{"gene":"CCL8","run_date":"2026-06-09T22:57:17","timeline":{"discoveries":[{"year":1992,"finding":"CCL8/MCP-2 was isolated from cytokine-stimulated human osteosarcoma cells (MG-63), identified by peptide sequencing, and shown to specifically attract monocytes but not neutrophils in vitro and in vivo (intradermal injection in rabbits). It was classified as a CC chemokine with conserved cysteine residues, structurally related to MCP-1.","method":"Protein purification, peptide sequencing, chemotaxis assay (Boyden chamber), in vivo injection","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 1 / Strong — direct biochemical isolation, sequencing, and functional chemotaxis assays; foundational characterization paper replicated by subsequent studies","pmids":["1613466"],"is_preprint":false},{"year":1994,"finding":"Synthetic CCL8/MCP-2 (76-residue protein) was chemotactic for monocytes at 1 nM; IFN-γ was identified as a superior inducer of MCP-2 (compared to IL-1β for MCP-1) in fibroblasts, while granulocytes were inefficient producers. Regulation of MCP-1 and MCP-2 expression was shown to be non-identical.","method":"Chemical synthesis, radioimmunoassay (RIA), cytokine stimulation of human fibroblasts and leukocytes","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 1 / Strong — synthetic protein validated biochemically, multiple cell types and inducers tested with quantitative assays","pmids":["8189067"],"is_preprint":false},{"year":1994,"finding":"CCL8/MCP-2 induced migration of human CD4+ and CD8+ T lymphocytes with a bimodal concentration dependence, elicited cytosolic Ca2+ increases blocked by pertussis toxin (indicating G-protein-coupled receptor involvement), and desensitization experiments showed MCP-1, MCP-2, and MCP-3 share receptors on T cells.","method":"Chemotaxis assay, intracellular Ca2+ measurement, pertussis toxin treatment, receptor desensitization, radioligand binding","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal functional assays; receptor sharing confirmed by cross-desensitization and binding competition","pmids":["7926371"],"is_preprint":false},{"year":1994,"finding":"CCL8/MCP-2 attracted human eosinophils (ED50 ~40 nM) and cross-desensitized eosinophil chemotactic responses to RANTES, indicating CCL8 and MCP-3 signal through the same receptor on eosinophils as RANTES.","method":"Boyden chamber eosinophil chemotaxis assay, cross-desensitization experiments","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional chemotaxis and desensitization in primary cells, single lab","pmids":["7514401"],"is_preprint":false},{"year":1995,"finding":"CCL8/MCP-2 actions on human monocytes include bimodal migration, N-acetyl-β-D-glucosaminidase release, and Ca2+ transients. Cross-desensitization showed MCP-1, MCP-2, and MCP-3 share a receptor subgroup on monocytes distinct from the RANTES/MIP-1α/MIP-1β subgroup, though MCP-2 also partially interacts with the latter. Radiolabeled MCP-1 binding was competed by all MCPs; MCP-3 (but not MCP-1/MCP-2) fully displaced MIP-1α.","method":"Migration assay, exocytosis assay, Ca2+ measurement, cross-desensitization, radioligand binding competition","journal":"European journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods on primary human monocytes; receptor sharing established by reciprocal desensitization and binding","pmids":["7531149"],"is_preprint":false},{"year":1995,"finding":"CCL8/MCP-2 induced mediator release in human basophils (lower efficacy than MCP-1/MCP-3), Ca2+ transients, and chemotaxis in both basophils and eosinophils. Desensitization studies indicated MCP-2 interacts with receptors recognizing both MCP-1 and RANTES. In IL-3-untreated basophils, MCP-2 acted as a functional inhibitor of other CC chemokine actions.","method":"Mediator release assay, Ca2+ measurement, chemotaxis assay, cross-desensitization","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal functional assays in primary cells demonstrating both agonist and antagonist activities","pmids":["7535823"],"is_preprint":false},{"year":1995,"finding":"CCL8/MCP-2 and MCP-3 were chemically synthesized using Fmoc solid-phase chemistry, correctly folded with disulfide bridges in glutathione redox buffer, and shown to be chemotactic for monocytes at 7.5 ng/ml and 5 ng/ml respectively, equivalent to natural chemokines. Neither induced neutrophil chemotaxis.","method":"Solid-phase peptide synthesis, RP-HPLC purification, disulfide bridge formation, monocyte chemotaxis assay","journal":"Cytokine","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution from synthetic protein with full biochemical validation and functional equivalence to natural protein","pmids":["7780043"],"is_preprint":false},{"year":1997,"finding":"CCL8/MCP-2 uses CCR1 and CCR2B as functional receptors. 125I-MCP-2 bound to HEK293 cells transfected with CCR1 or CCR2B; binding was displaced by known CCR1/CCR2B ligands. Both CCR1- and CCR2B-transfected cells showed significant chemotactic migration in response to MCP-2.","method":"Radioiodinated ligand binding assay, receptor-transfected cell chemotaxis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct radioligand binding and functional migration assay on receptor-transfected cells; replicated by subsequent studies","pmids":["9115216"],"is_preprint":false},{"year":1997,"finding":"The human MCP-2/CCL8 gene (SCYA8) was cloned and localized to chromosome 17q11.2 within the CC chemokine gene contig. The gene shares a conserved intron-exon structure with MCP-1 and MCP-3 genes. MCP-2 mRNA (1.0 kb) was predominantly detected in small intestine, peripheral blood, heart, placenta, lung, and other tissues.","method":"YAC contig PCR cloning, genomic sequencing, Northern blot analysis","journal":"Genomics","confidence":"High","confidence_rationale":"Tier 1 / Strong — direct genomic cloning and sequencing with Northern blot expression profiling","pmids":["9119400"],"is_preprint":false},{"year":1998,"finding":"CCL8/MCP-2 binds CCR5 with high affinity and is a true CCR5 agonist, eliciting robust chemotaxis in CCR5 transfectants, cross-desensitization with RANTES on Ca2+ flux, and inhibiting M-tropic HIV-1 gp120 binding to CCR5 and HIV-1 infection of PBMCs. On activated CD3+/IL-2 T cells, CCL8-mediated chemotaxis was predominantly inhibited by anti-CCR5 mAb 2D7, establishing CCR5 as the primary receptor on these cells.","method":"Radioligand binding, chemotaxis of CCR5 transfectants, Ca2+ flux cross-desensitization, HIV-1 binding inhibition assay, anti-CCR5 mAb blocking","journal":"Cellular immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods including binding, functional migration, receptor blockade, and antiviral assays","pmids":["9790730"],"is_preprint":false},{"year":1999,"finding":"The CCL8/MCP-2 gene promoter region between -340 and -301 (relative to transcription start site) is required for IFN-γ-induced transcription in fibroblasts and osteosarcoma cells. The region -143 to -73 (containing putative GATA-1, H-APF1, AP-1, and GAS elements) is important for basal transcription. IL-1β alone failed to induce expression, but synergized with IFN-γ in osteosarcoma cells. Transcription factors in nuclear extracts were shown to bind the -340/-301 region by EMSA.","method":"5'-deletion mutagenesis, luciferase reporter assay, electromobility shift assay (EMSA)","journal":"Journal of leukocyte biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — promoter deletion mutagenesis with luciferase readout plus EMSA; single lab but two orthogonal methods","pmids":["10496322"],"is_preprint":false},{"year":2000,"finding":"Neutrophil gelatinase B (MMP-9) does not digest CCL8/MCP-2 (or RANTES), in contrast to its processing of IL-8, CTAP-III, PF-4, and GRO-alpha. This establishes that CCL8 is resistant to MMP-9-mediated aminoterminal processing.","method":"In vitro protease digestion assay with purified gelatinase B","journal":"Blood","confidence":"High","confidence_rationale":"Tier 1 / Strong — direct in vitro enzymatic assay with purified proteins; negative result for CCL8 is mechanistically informative","pmids":["11023497"],"is_preprint":false},{"year":2003,"finding":"The orphan mouse chemokine receptor L-CCR expressed in HEK293 cells showed pertussis toxin-sensitive chemotaxis and intracellular Ca2+ transients in response to CCL8 (and CCL2, CCL5, CCL7). Biotinylated CCL2 bound L-CCR-expressing cells, and L-CCR-GFP fusion protein localized to cell membranes.","method":"Receptor transfection in HEK293, chemotaxis assay, Ca2+ measurement, pertussis toxin treatment, biotinylated ligand binding, GFP fusion protein localization","journal":"Journal of leukocyte biology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — functional assays in transfected cells, single lab; radioligand binding not detected, limiting confidence","pmids":["12885941"],"is_preprint":false},{"year":2005,"finding":"TRAIL pretreatment of endothelial cells abrogated TNF-α-mediated upregulation of CCL8 and CXCL10 mRNA, as identified by cDNA microarray. Addition of recombinant CCL8 plus CXCL10 to endothelial cultures completely restored the proadhesive activity of TNF-α, demonstrating that CCL8 contributes to leukocyte/endothelial adhesion. Both TRAIL-R1 and TRAIL-R2 contributed to this chemokine modulation.","method":"cDNA microarray, qPCR, recombinant protein rescue experiment, agonistic anti-TRAIL receptor antibodies","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — microarray identified CCL8 target; functional rescue with recombinant protein confirmed mechanistic role; single lab","pmids":["15644410"],"is_preprint":false},{"year":2009,"finding":"Intact CCL8/MCP-2(1-76) produced by fibroblasts is processed into CCL8(6-75) under synergistic IFN-γ + IL-1β (or TLR ligand) stimulation. The truncated isoform CCL8(6-75) lacked chemotactic activity for monocytes and had severely reduced capacity to increase intracellular Ca2+ via CCR1, CCR2, CCR3, and CCR5. However, CCL8(6-75) still blocked these receptors, induced CCR2 internalization, inhibited MCP-1/CCL2 and MCP-2/CCL8 ERK signaling, and antagonized chemotactic activity of several CCR2 ligands.","method":"Protein purification, N-terminal sequencing, Ca2+ flux assay, chemotaxis assay, receptor internalization assay, ERK phosphorylation assay","journal":"European journal of immunology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — direct biochemical identification of cleavage product with multiple orthogonal functional readouts demonstrating agonist-to-antagonist conversion","pmids":["19224633"],"is_preprint":false},{"year":2010,"finding":"CCL8/MCP-2 is a direct target of miR-146a in HIV-1-infected human microglial cells. Overexpression of miR-146a prevented HIV-induced secretion of MCP-2. In HIV-encephalitis brain samples, decreased MCP-2 levels coincided with increased miR-146a, suggesting post-transcriptional regulation of CCL8 by miR-146a during chronic neuroinflammation.","method":"miRNA overexpression, ELISA for MCP-2 secretion, HIV-1 infection of primary microglial cells, brain tissue analysis","journal":"FASEB journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional overexpression experiment in primary cells with protein-level readout; mechanistic targeting confirmed but full luciferase validation not described in abstract","pmids":["20181935"],"is_preprint":false},{"year":2010,"finding":"Stromal cell-derived CCL8 cooperated with CXCL12 to attract hematopoietic progenitors capable of differentiating into regulatory dendritic cells. Leishmania donovani infection of murine bone marrow stromal cells enhanced CCL8 production and their capacity to support regulatory DC development. In experimental visceral leishmaniasis, CCL8 production was induced in splenic stromal cells.","method":"Hematopoietic progenitor migration assay, stromal cell infection, in vivo murine leishmaniasis model, DC differentiation assay","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional migration and differentiation assays with in vivo model; single lab","pmids":["20624948"],"is_preprint":false},{"year":2011,"finding":"Mouse CCL8 is a CCR8 agonist but not a CCR2 agonist, distinguishing it from all other MCP chemokines. CCL8-CCR8 signaling defines a population of highly differentiated CCR8-expressing inflammatory Th2 cells enriched for IL-5. Ccr8- and Ccl8-deficient mice had markedly less eosinophilic inflammation in a chronic atopic dermatitis model. Adoptive transfer studies established CCR8 as a key regulator of Th2 cell recruitment into allergen-inflamed skin.","method":"Receptor binding/signaling assays, Ccr8/Ccl8 knockout mice, chronic atopic dermatitis model, adoptive transfer studies, flow cytometry","journal":"Nature immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods including KO mice, adoptive transfer, and cell biology; replicated in human CCR8+ T cell subset","pmids":["21217759"],"is_preprint":false},{"year":2013,"finding":"Mycobacterium bovis BCG and M. tuberculosis H37Rv infection induced CCL8/MCP-2 production in macrophage cell lines and primary macrophages through TLR2/PI3K/Akt and p38 signaling pathways. CCR5 (primary receptor for MCP-2/CCL8) was predominantly expressed on pleural CD4+ T lymphocytes in TB patients, suggesting CCL8 mediates T lymphocyte recruitment in pleural TB.","method":"Mycobacterial infection of macrophages, signaling pathway inhibitors, qPCR, protein array, flow cytometry on patient samples","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pathway inhibitor experiments in multiple cell types; single lab, no genetic confirmation of TLR2 requirement","pmids":["23418602"],"is_preprint":false},{"year":2014,"finding":"BLIMP1 is a direct transcriptional repressor of CCL8 in macrophages. BLIMP1-deficient macrophages expressed elevated Ccl8, and Blimp1 CKO mice had higher circulating CCL8 and increased neutrophils, promoting antibacterial responses. CCL8 was chemotactic for γ/δ T cells enriched for IL-17F, and CCL8-mediated clearance of Listeria monocytogenes was dependent on γ/δ T cells. CCL8 failed to recruit neutrophils directly.","method":"Conditional knockout mice (Blimp1 CKO in myeloid cells), transcriptome analysis, Ccl8 knockout mice, Listeria infection model, chemotaxis assay, γ/δ T cell depletion","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO with transcriptomics, Ccl8 KO mice, infection model, and cell depletion experiments; multiple orthogonal approaches","pmids":["24477914"],"is_preprint":false},{"year":2014,"finding":"LAcmvIL-10 (HCMV latency-associated viral IL-10) is responsible for increased CCL8 secretion from latently infected myeloid progenitors. This occurs through LAcmvIL-10-mediated suppression of cellular microRNA hsa-miR-92a, which directly targets CCL8. Downregulation of hsa-miR-92a thus upregulates CCL8 during HCMV latency.","method":"Latent infection of primary myeloid progenitors, miRNA expression analysis, secretome analysis","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional viral gene expression experiments linking viral protein to miRNA to CCL8; single lab","pmids":["25253336"],"is_preprint":false},{"year":2016,"finding":"CCL8 is produced by F4/80+ macrophages in the lungs of mice with metastatic primary tumors and drives CCR5-dependent Treg migration. Ex vivo Treg migration toward CCL8 was reduced by CCR5 inhibitor Maraviroc. Maraviroc treatment reduced CCR5+ Tregs and metastatic tumor burden in lungs, establishing a CCL8/CCR5 signaling axis for Treg recruitment.","method":"Ex vivo migration assay, flow cytometry, Maraviroc treatment, immunofluorescence, in vivo metastasis model","journal":"Oncoimmunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional migration assay with pharmacological inhibition and in vivo validation; single lab","pmids":["27471618"],"is_preprint":false},{"year":2017,"finding":"Recombinant CCL8 produced in E. coli binds CCR3 with a dissociation equilibrium constant (KD) of 1.2 × 10-7 M as measured by quartz crystal microbalance. CCL8 induced internalization of CCR3 in vivo within 1 hour at 100 nM and elicited weaker chemotactic effects in CCR3-expressing cells compared to CCL11 and CCL24.","method":"Recombinant protein production, quartz crystal microbalance binding assay, receptor internalization assay, chemotaxis assay","journal":"BMC immunology","confidence":"Medium","confidence_rationale":"Tier 1-2 / Moderate — direct in vitro binding assay with defined KD and functional internalization assay; single lab","pmids":["29281969"],"is_preprint":false},{"year":2017,"finding":"CCL8 expression in spinal neurons (co-localized with NeuN marker) was upregulated following TNBS-induced colonic inflammation. Intrathecal CCL8 neutralizing antibody or CCR5 antagonist DAPTA dose-dependently suppressed TNBS-evoked visceral hyperalgesia and spinal ERK activation, establishing a CCL8/CCR5/ERK pathway in spinal cord visceral pain maintenance.","method":"TNBS colitis model, immunohistochemistry, qPCR/Western blot, intrathecal antibody/antagonist injection, colorectal distension pain assay, ERK phosphorylation analysis","journal":"Brain research bulletin","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological blockade with defined pathway readout in vivo; single lab","pmids":["29037608"],"is_preprint":false},{"year":2018,"finding":"miR-146a-5p directly targets the 3'-UTR of CCL8, as confirmed by dual-luciferase reporter assay. In Neuro-2a cells, TNF-α-induced CCL8 upregulation was decreased by miR-146a-5p mimic. Intrathecal miR-146a-5p agomir reduced CCL8 expression and relieved visceral pain in colitis mice; intrathecal antagomir upregulated CCL8 and induced pain hypersensitivity that was partially rescued by CCL8 neutralization.","method":"Dual-luciferase reporter assay, miRNA mimic/inhibitor transfection, intrathecal injection, TNBS colitis model, pain threshold measurement","journal":"Brain research bulletin","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — luciferase 3'-UTR validation plus in vivo gain/loss of function with rescue experiment; single lab but multiple orthogonal approaches","pmids":["29550454"],"is_preprint":false},{"year":2019,"finding":"Hypoxia-induced ZEB1 activates CCL8 transcription in cervical cancer cells, which attracts macrophages via the CCR2-NF-κB pathway. ZEB1 knockdown altered expression of multiple chemokines with CCL8 being most affected, and CCL8-dependent macrophage migration was demonstrated in vitro.","method":"Hypoxia treatment, ZEB1 knockdown/overexpression, chemokine expression profiling, macrophage migration assay, CCR2-NF-κB pathway analysis","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain/loss of function with defined pathway; single lab, in vitro mechanism","pmids":["31263103"],"is_preprint":false},{"year":2019,"finding":"miR-345-5p directly targets CCL8 (confirmed by luciferase assay) and inversely correlates with CCL8 expression in PDAC samples. CCL8 activates the NF-κB signaling pathway to promote proliferation and invasiveness of pancreatic cancer cells.","method":"Luciferase reporter assay, miRNA overexpression, Western blot for NF-κB pathway, Transwell invasion assay","journal":"Biomedicine & pharmacotherapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — luciferase 3'-UTR validation and pathway analysis; single lab","pmids":["30841468"],"is_preprint":false},{"year":2020,"finding":"CCL8 promotes migratory ability of endometrial epithelial and stromal cells and increases proliferation, migration, and tube formation of endothelial cells through CCR1. CCR1, overexpressed in ectopic endometrium and co-localized with blood vessels, when inhibited suppressed endometriosis development and angiogenesis in vivo. CCL8 was upregulated in mast cells when co-cultured with endometrial cells.","method":"Co-culture system, Transwell migration assay, CCK-8 proliferation assay, tube formation assay, CCR1 inhibition in vivo mouse model","journal":"Biomedicine & pharmacotherapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional assays in vitro and in vivo with CCR1 inhibitor; single lab","pmids":["32768961"],"is_preprint":false},{"year":2020,"finding":"CCL8 is highly expressed during mammary gland involution and enhances infiltration of M2 subtype macrophages at the second phase of involution. In Ccl8-deficient animals, CCL8 accelerated tumor onset during involution but not in nulliparous animals. Macrophage depletion abolished the tumor-promoting effect of CCL8, establishing that CCL8 promotes postpartum breast cancer by recruiting M2 macrophages.","method":"Ccl8-deficient mice, cancer cell inoculation studies, macrophage depletion, immunohistochemistry","journal":"iScience","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mice with macrophage depletion rescue experiment; multiple orthogonal approaches confirming mechanism","pmids":["32535027"],"is_preprint":false},{"year":2021,"finding":"CCL8 from endothelial colony forming cells (ECFCs) induces IL-8 secretion from TNBC cells via c-Jun as a transcription factor. A positive feedback loop between CCL8 and IL-8 contributes to invasion, migration, MMP-2 secretion, and angiogenesis. CCL8 was crucial for ECFC-induced invasion of MDA-MB-231 cells.","method":"Indirect co-culture, cytokine antibody array, RT-PCR, siRNA knockdown, xenograft model, transcription factor identification","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional co-culture with knockdown and in vivo validation; single lab","pmids":["33833397"],"is_preprint":false},{"year":2021,"finding":"CCL8 plays a major role in acute GVHD pathogenesis. CCL8-knockout mice showed markedly reduced mortality (23.4% vs. 90% in wild-type) and attenuated liver dysfunction after allogeneic bone marrow transplantation. CCL8 deficiency was associated with a surge in plasma IL-6 in allograft recipients, suggesting CCL8 involvement in an IL-6 signaling cascade during aGVHD.","method":"CCL8 knockout mice, allogeneic bone marrow transplantation, survival analysis, plasma cytokine measurement, histopathology","journal":"Experimental hematology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO with clear phenotypic outcome and cytokine pathway identification; single lab but definitive genetic evidence","pmids":["34808257"],"is_preprint":false},{"year":2022,"finding":"Iron augmented Fusobacterium nucleatum-induced CCL8 expression in macrophages via TLR4/NF-κB signaling. Mechanistically, iron attenuated inhibitory phosphorylation of NF-κB p65 by activating serine/threonine phosphatases, thereby augmenting tumor-promoting chemokine production.","method":"qRT-PCR, Western blot, NF-κB signaling analysis, iron deficiency/supplementation experiments","journal":"JCI insight","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mechanistic signaling pathway identified with biochemical validation; single lab","pmids":["36136589"],"is_preprint":false},{"year":2022,"finding":"Donor kidney resident macrophages rapidly induced Ccl8 expression within 3 days post-transplant, which promoted recipient monocyte graft infiltration and their differentiation to resident macrophages, which in turn also expressed Ccl8. CCL8-CCR8 signaling then enhanced CCR8+ T cell (CD4, CD8, γδ) infiltration. Blocking CCL8-CCR8 or depleting donor kidney resident macrophages significantly inhibited early allograft immune cell infiltration and improved short-term function.","method":"Allogeneic murine kidney transplant model, CCL8-CCR8 blockade, macrophage depletion, flow cytometry, single-cell analysis","journal":"Journal of the American Society of Nephrology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic/pharmacological blockade in vivo with functional outcome; multiple cell populations characterized","pmids":["35973731"],"is_preprint":false},{"year":2023,"finding":"Lactate induced M2 macrophage polarization via AKT/ERK signaling pathway; M2 macrophages subsequently secreted CCL8 which facilitated colorectal cancer cell proliferation and metastasis by activating the CCL8/CCR5/mTORC1 axis. CCR5 antagonism or knockdown inhibited this protumorigenic effect.","method":"qRT-PCR, Western blot, RNA-seq, wound healing assay, colony formation assay, CCR5 knockdown/antagonist, allograft mouse model","journal":"Cancers","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CCR5 genetic knockdown and pharmacological inhibition with in vivo validation; single lab","pmids":["38136340"],"is_preprint":false},{"year":2023,"finding":"IFN-γ stimulation of fibroblasts via JAK-STAT signaling upregulated CCL2 and CCL8 expression. CCL2 addition to naïve T cell polarization promoted type 2 cytokine secretion. JAK inhibitor peficitinib abrogated IFN-γ-induced CCL2 and CCL8 upregulation in fibroblasts.","method":"RNA sequencing of vitiligo mouse model fibroblasts, JAK inhibitor treatment, qPCR, Western blot, T cell polarization assay, flow cytometry","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — JAK-STAT pathway identified with pharmacological validation; single lab","pmids":["36672151"],"is_preprint":false},{"year":2023,"finding":"MSCs enhanced CCL8 expression by podocytes in a contact-dependent manner (blocked by anti-VCAM-1 antibody, shown by transwell assay). Conversely, podocyte-derived CCL8 potentiated immunosuppressive activity of MSCs (increased IL-10, IDO, TGF-β1, iNOS production and stronger inhibition of IFN-γ by T cells).","method":"Co-culture, transwell assay, anti-VCAM-1 antibody blocking, qPCR/Western blot, T cell suppression assay","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — contact-dependent mechanism established with blocking antibody; bidirectional functional readouts; single lab","pmids":["37567910"],"is_preprint":false},{"year":2024,"finding":"Muscle cell-derived Ccl8 (from Pax7+, Myf5+, or MyoD+ myogenic progenitor cells) negatively regulates skeletal muscle regeneration. CRISPR-based depletion of Ccl8 in Pax7+ MPCs accelerated muscle regeneration after injury in both young and middle-aged mice. Intramuscular administration of recombinant Ccl8 reversed this accelerated regeneration phenotype, establishing Ccl8 as a negative regulator of myogenic differentiation initiation.","method":"Ccl8 knockdown in C2C12 myoblasts, AAV9-delivered sgRNA/Cas9 in vivo gene editing in Pax7+/Myf5+/MyoD+ cells, barium chloride injury model, recombinant CCL8 rescue","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo conditional gene editing with recombinant protein rescue in multiple MPC lineages; multiple orthogonal approaches","pmids":["39051762"],"is_preprint":false},{"year":2025,"finding":"CCL8 is identified as a critical mediator downstream of GAS6/AXL/MERTK signaling in tumor-associated macrophages (Reg-TAMs) that facilitates immune escape of tumor-initiating cells primarily by inhibiting Treg infiltration into the tumor. AXL/MERTK inhibition reactivated antitumor immunity and sensitized tumor cells to anti-PD-1 treatment.","method":"scRNA-seq, lineage tracing, chemical inhibitors, Axl/Mertk conditional double-KO mice, anti-PD-1 combination studies","journal":"The Journal of clinical investigation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — conditional KO with scRNA-seq and functional immunological readouts; single lab","pmids":["39774471"],"is_preprint":false},{"year":2025,"finding":"USP18 stabilizes SOCS1 by inhibiting its ubiquitination and degradation, leading to reduced CCL8 production in AT2 cells through the ERK-STAT3 signaling pathway. USP18 deficiency increased CCL8 in AT2 cells, recruiting Th2 cells and eosinophils to exacerbate allergic asthma. CCL8 knockdown in AT2 cells of USP18 KO mice alleviated asthma symptoms.","method":"USP18 KO mice, AT2 cell-specific CCL8 knockdown, exogenous CCL8 treatment, SOCS1 ubiquitination assay, ERK-STAT3 pathway analysis","journal":"Respiratory research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with pathway mechanistic analysis and CCL8 knockdown rescue; single lab","pmids":["41354823"],"is_preprint":false},{"year":2025,"finding":"DTCCL8, a chimeric diphtheria toxin-CCL8 cytotoxic peptide, was developed to ablate cells expressing CCL8 receptors (particularly CCR5). Its specificity was confirmed in vitro by testing cytotoxic activity on CCR5-overexpressing breast cancer cells and by neutralizing anti-CCL8 antibody. In vivo, DTCCL8 showed anticancer activity in polyoma middle T oncogene-driven mouse breast cancers.","method":"Chimeric protein construction, in vitro cytotoxicity on CCR5-expressing cells, anti-CCL8 neutralizing antibody, in vivo mouse breast cancer model","journal":"Molecular oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro and in vivo functional validation of CCL8-receptor targeting; single lab","pmids":["40545574"],"is_preprint":false},{"year":2025,"finding":"HSP90 interacts with transcription factor STAT1 and stabilizes its expression, driving CCL8 expression in atrial cardiomyocytes. CCL8 mediates macrophage recruitment and local atrial inflammation in hypertension-induced atrial fibrillation. STAT1 knockdown attenuated CCL8 upregulation and the inflammatory cascade.","method":"RNA sequencing, AngII-induced AF mouse model, HSP90 inhibitor (17AAG), STAT1 knockdown, Western blot, co-IP (HSP90-STAT1 interaction inferred)","journal":"Life sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — STAT1 KD with in vivo model and HSP90 inhibitor; mechanistic link established but co-IP confirmation not explicitly described in abstract","pmids":["41720180"],"is_preprint":false},{"year":2025,"finding":"JMJD1A (KDM3A) promotes CCL8 expression in colonic epithelial cells by demethylating H3K9me2 on both the IRF1 promoter (cooperating with STAT1 to upregulate IRF1) and the CCL8 promoter directly (cooperating with IRF1). CCL8 mediates recruitment of macrophages and CD4+ T cells, and JMJD1A-/- mice showed impaired CCL8 induction and reduced immune cell recruitment after C. rodentium infection.","method":"JMJD1A knockout mice, C. rodentium infection model, ChIP for H3K9me2, promoter analysis, flow cytometry for immune cell recruitment","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO mice with ChIP-based epigenetic mechanism; single lab","pmids":["41779805"],"is_preprint":false},{"year":2025,"finding":"CBX6 promotes CCL8 expression in esophageal squamous cell carcinoma cells through SMARCD1-mediated chromatin remodeling. CBX6 regulated SMARCD1 expression to modulate chromatin remodeling, thereby promoting CCL8 transcription. CCL8 secretion contributed to CD8+ T cell exhaustion and reduced cytotoxicity.","method":"Cbx6 knockdown, SMARCD1 overexpression, co-culture with CD8+ T cells, in vivo tumorigenesis model, tissue microarray","journal":"Cell biology and toxicology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic knockdown with in vivo validation and chromatin remodeling mechanism; single lab","pmids":["41219497"],"is_preprint":false},{"year":2026,"finding":"P16+ fibroblasts and macrophages after myocardial infarction are the main sources of CCL8 in the heart. CCL8 blockade or genetic deletion of Ccl8 in P16+ cells reduced infiltration of cytotoxic lymphocytes (CD8+ T cells and NK cells), decreased cardiomyocyte apoptosis, and enhanced cardiac repair. Ablation of P16+ fibroblasts (but not macrophages) diminished fibrosis.","method":"p16-CreER reporter mice, dasatinib/quercetin senolytic treatment, bulk and scRNA-seq of P16+ cells, CCL8 neutralization, Ccl8 deletion in P16+ cells, CD8+ T cell depletion, dual-recombinase intersectional genetics","journal":"Circulation","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional genetic deletion, neutralization antibody, cell depletion, and dual-recombinase lineage tools; multiple orthogonal approaches confirming CCL8 mechanism","pmids":["41766526"],"is_preprint":false},{"year":2021,"finding":"Recombinant mouse CCL8 stimulation of NIH/3T3 fibroblasts significantly increased collagen expression and ERK1/2 phosphorylation, suggesting CCL8 drives fibrosis via ERK1/2 phosphorylation. Anti-CCL8 neutralizing antibody improved focus and fibrosis scores in an IgG4-related sialadenitis mouse model (LAT Y136F knockin mice).","method":"Recombinant CCL8 stimulation of fibroblasts, Western blot for ERK1/2 phosphorylation, collagen expression assay, anti-CCL8 antibody treatment in vivo","journal":"Arthritis research & therapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro signaling pathway with in vivo antibody blockade; single lab","pmids":["34391459"],"is_preprint":false},{"year":2025,"finding":"CCL8 induced M1 macrophage polarization in THP1-derived macrophages; conditioned medium from these macrophages suppressed ovarian cancer cell proliferation, migration, invasion, and EMT. Mechanistically, CCL8-induced macrophages promoted apoptosis in OC cells via activation of the NF-κB p65 pathway (increased Bax and Caspase3), which was reversed by p65 inhibition.","method":"Macrophage polarization assay, conditioned medium transfer, NF-κB inhibition, Western blot for apoptosis markers, proliferation/invasion assays","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pathway inhibition rescue experiment with functional readouts; single lab","pmids":["41408455"],"is_preprint":false},{"year":2026,"finding":"Neoadjuvant chemotherapy activates the MAPK pathway in gastric cancer cells, inducing CCL8 secretion which facilitates NK cell recruitment. In vitro, NACT-treated tumor cells showed enhanced chemotactic effects on NK92 cells, and NACT-induced CCL8 was identified as the mechanistic driver of NK cell recruitment.","method":"In vitro NACT treatment, chemotaxis assay, MAPK pathway analysis, in vivo NK cell depletion","journal":"Cancer immunology, immunotherapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — MAPK pathway identified with functional chemotaxis assay and NK depletion in vivo; single lab","pmids":["41843172"],"is_preprint":false}],"current_model":"CCL8/MCP-2 is a secreted CC chemokine that signals through multiple receptors (CCR1, CCR2B, CCR3, CCR5, and CCR8 in mice) via pertussis toxin-sensitive G-protein-coupled pathways to attract monocytes, T cells, basophils, eosinophils, and NK cells; its transcription is induced by IFN-γ via a promoter element at -340/-301 (and synergistically by IL-1β), repressed by BLIMP1 and miR-146a/miR-92a, and can be processed from active CCL8(1-76) into a receptor-blocking antagonist form CCL8(6-75); in disease contexts CCL8 drives Th2 inflammation through the CCL8-CCR8 axis, promotes macrophage and Treg recruitment in tumors, drives fibrosis via ERK1/2 in fibroblasts, mediates visceral pain through spinal CCR5/ERK signaling, acts as a negative regulator of muscle regeneration from myogenic progenitors, and orchestrates post-myocardial infarction remodeling through P16+ cell-derived CCL8-dependent cytotoxic lymphocyte recruitment."},"narrative":{"mechanistic_narrative":"CCL8/MCP-2 is a secreted CC chemokine that orchestrates leukocyte recruitment across inflammation, infection, fibrosis, and tumor immunity by signaling through multiple G-protein-coupled receptors [PMID:1613466, PMID:7926371]. Originally isolated from cytokine-stimulated osteosarcoma cells as a monocyte-specific chemoattractant structurally related to MCP-1, it also recruits CD4+ and CD8+ T lymphocytes, eosinophils, and basophils via pertussis toxin-sensitive, calcium-mobilizing signaling [PMID:1613466, PMID:7926371, PMID:7514401, PMID:7535823]. CCL8 is functionally promiscuous, acting as an agonist at CCR1 and CCR2B [PMID:9115216], CCR5 [PMID:9790730], and CCR3 [PMID:29281969], with cross-desensitization establishing overlapping receptor usage shared with MCP-1, MCP-3, and RANTES on monocytes and eosinophils [PMID:7514401, PMID:7531149]; in mice CCL8 uniquely activates CCR8 rather than CCR2, defining a CCL8-CCR8 axis that recruits inflammatory Th2 cells and drives eosinophilic skin inflammation [PMID:21217759]. The mature CCL8(1-76) protein is proteolytically converted under synergistic IFN-γ plus IL-1β/TLR stimulation into CCL8(6-75), which loses agonist activity yet retains the ability to block CCR1/2/3/5, internalize CCR2, and antagonize ERK signaling and chemotaxis—an agonist-to-antagonist switch—while remaining resistant to MMP-9 processing [PMID:11023497, PMID:19224633]. Its expression is induced by IFN-γ through a -340/-301 promoter element and JAK-STAT signaling [PMID:10496322, PMID:36672151], by NF-κB downstream of TLR2/TLR4 microbial sensing [PMID:23418602, PMID:36136589], and by chromatin and transcription factor regulators including ZEB1, STAT1, IRF1/JMJD1A, and CBX6/SMARCD1 [PMID:31263103, PMID:41720180, PMID:41779805, PMID:41219497], and is repressed transcriptionally by BLIMP1 and post-transcriptionally by miR-146a and miR-92a [PMID:24477914, PMID:20181935, PMID:25253336, PMID:29550454]. Through these axes CCL8 recruits immunosuppressive and cytotoxic cells in disease: it drives macrophage and Treg recruitment to promote tumor growth and metastasis [PMID:27471618, PMID:32535027], mediates allograft rejection and acute GVHD [PMID:34808257, PMID:35973731], drives ERK1/2-dependent fibroblast collagen production in fibrosis [PMID:34391459], maintains spinal CCR5/ERK visceral pain signaling [PMID:29037608, PMID:29550454], negatively regulates myogenic muscle regeneration [PMID:39051762], and is produced by P16+ senescent fibroblasts and macrophages after myocardial infarction to recruit cytotoxic lymphocytes and impair cardiac repair [PMID:41766526].","teleology":[{"year":1992,"claim":"Establishing that a distinct MCP-1-related CC chemokine existed answered whether a separate monocyte-selective chemoattractant could be biochemically purified and functionally defined.","evidence":"Protein purification, peptide sequencing, and chemotaxis from cytokine-stimulated osteosarcoma cells","pmids":["1613466"],"confidence":"High","gaps":["No receptor identified","Cell selectivity beyond monocytes/neutrophils unexplored"]},{"year":1994,"claim":"Synthetic protein and cytokine-induction studies established CCL8's intrinsic chemotactic potency and that its regulation diverges from MCP-1, with IFN-γ as the superior inducer.","evidence":"Chemical synthesis, RIA, and cytokine stimulation of fibroblasts/leukocytes; T-cell chemotaxis with pertussis-toxin-sensitive Ca2+ flux","pmids":["8189067","7926371"],"confidence":"High","gaps":["Specific receptor identity not resolved","Mechanism of differential regulation versus MCP-1 unknown"]},{"year":1995,"claim":"Cross-desensitization across leukocyte types resolved the question of CCL8 receptor usage, showing it shares receptor subgroups with MCP-1/MCP-3 and partially with RANTES, and can act as a functional inhibitor on basophils.","evidence":"Chemotaxis, Ca2+, mediator-release and radioligand competition on primary monocytes, eosinophils, and basophils","pmids":["7531149","7535823","7514401","7780043"],"confidence":"High","gaps":["Receptor identities defined only by cross-competition, not molecular cloning","Basis of agonist versus inhibitor behavior unclear"]},{"year":1997,"claim":"Receptor-transfection binding assays identified the molecular receptors CCR1 and CCR2B, converting inferred receptor sharing into defined ligand-receptor pairs, alongside genomic cloning to chromosome 17q11.2.","evidence":"Radioiodinated ligand binding and chemotaxis on CCR1/CCR2B-transfected HEK293 cells; YAC contig cloning and Northern blot","pmids":["9115216","9119400"],"confidence":"High","gaps":["Relative contribution of each receptor in vivo unknown","Tissue-specific receptor coupling not addressed"]},{"year":1998,"claim":"Demonstration of high-affinity CCR5 agonism resolved CCL8's primary receptor on activated T cells and revealed an antiviral capacity by blocking M-tropic HIV-1 entry.","evidence":"Radioligand binding, CCR5-transfectant chemotaxis, anti-CCR5 mAb blockade, and HIV-1 gp120 binding/infection inhibition","pmids":["9790730"],"confidence":"High","gaps":["In vivo relevance of HIV inhibition untested","CCR5 signaling output not detailed"]},{"year":1999,"claim":"Promoter dissection answered how IFN-γ drives CCL8 transcription, mapping an inducible -340/-301 element and a basal -143/-73 region with IL-1β synergy.","evidence":"5'-deletion luciferase reporters and EMSA in fibroblasts/osteosarcoma cells","pmids":["10496322"],"confidence":"High","gaps":["Identity of the -340/-301 binding factors not established","STAT involvement inferred, not proven at this stage"]},{"year":2000,"claim":"Protease specificity testing established that CCL8 resists MMP-9 N-terminal processing, distinguishing its post-translational regulation from CXC chemokines.","evidence":"In vitro digestion with purified gelatinase B","pmids":["11023497"],"confidence":"High","gaps":["Other processing proteases not surveyed here","Functional consequence of resistance unaddressed"]},{"year":2009,"claim":"Identification of the CCL8(6-75) cleavage product answered how CCL8 activity is switched off and inverted, converting an agonist into a multi-receptor antagonist that blocks ERK and chemotaxis.","evidence":"Protein purification, N-terminal sequencing, Ca2+ flux, chemotaxis, receptor internalization, and ERK assays","pmids":["19224633"],"confidence":"High","gaps":["Identity of the processing protease not determined","In vivo abundance of antagonist form unknown"]},{"year":2010,"claim":"Discovery of miR-146a and miR-92a targeting CCL8 established post-transcriptional control during viral infection, complementing transcriptional regulation.","evidence":"miRNA overexpression with ELISA in HIV-infected microglia; HCMV latency secretome and miRNA analysis in myeloid progenitors","pmids":["20181935","25253336"],"confidence":"Medium","gaps":["Direct 3'-UTR binding not fully validated in 2010 microglial study","Generalizability across cell types unknown"]},{"year":2011,"claim":"Knockout and adoptive-transfer studies defined the mouse CCL8-CCR8 axis as a Th2-recruitment pathway, revealing receptor specificity distinct from all other MCPs.","evidence":"Ccl8/Ccr8 knockout mice, atopic dermatitis model, adoptive transfer, flow cytometry","pmids":["21217759"],"confidence":"High","gaps":["Human CCR8 agonism by CCL8 not equally established","Upstream inducers of CCL8 in skin not defined here"]},{"year":2014,"claim":"Genetic studies identified BLIMP1 as a direct transcriptional repressor of CCL8 and linked CCL8 to γδ T-cell-dependent antibacterial defense, defining a repression-controlled effector arm.","evidence":"Blimp1 conditional KO, Ccl8 KO, Listeria infection, chemotaxis, and γδ T-cell depletion","pmids":["24477914"],"confidence":"High","gaps":["Direct BLIMP1 binding site on Ccl8 not mapped","Receptor mediating γδ recruitment not identified"]},{"year":2016,"claim":"Tumor studies established a CCL8/CCR5 axis recruiting regulatory T cells, framing CCL8 as a driver of an immunosuppressive metastatic niche.","evidence":"Ex vivo Treg migration, Maraviroc CCR5 blockade, and in vivo lung metastasis model","pmids":["27471618"],"confidence":"Medium","gaps":["Maraviroc effects not CCL8-specific","Source-cell genetics not dissected"]},{"year":2020,"claim":"Macrophage-dependent tumor promotion by CCL8 was established genetically, showing CCL8 accelerates postpartum mammary tumorigenesis by recruiting M2 macrophages.","evidence":"Ccl8-deficient mice, tumor inoculation, and macrophage depletion rescue","pmids":["32535027"],"confidence":"High","gaps":["Receptor on recruited macrophages not specified","Context dependence on involution unexplained mechanistically"]},{"year":2021,"claim":"Genetic and pharmacologic studies extended CCL8's pathogenic reach to acute GVHD mortality and to ERK1/2-driven fibroblast collagen production in fibrosis.","evidence":"Ccl8 KO with allogeneic BMT and survival; recombinant CCL8 on fibroblasts with anti-CCL8 in IgG4-related sialadenitis","pmids":["34808257","34391459"],"confidence":"High","gaps":["GVHD effector receptor and cell type not defined","Fibroblast receptor mediating ERK activation not identified"]},{"year":2022,"claim":"Transplant and microbial studies clarified upstream control and downstream effects, showing donor macrophage Ccl8 drives CCR8+ T-cell graft infiltration and that iron amplifies TLR4/NF-κB-driven CCL8.","evidence":"Murine kidney transplant with CCL8-CCR8 blockade and macrophage depletion; iron/F. nucleatum macrophage NF-κB analysis","pmids":["35973731","36136589"],"confidence":"Medium","gaps":["Long-term graft outcomes not assessed","Phosphatase target of iron not fully mapped"]},{"year":2023,"claim":"Multiple studies converged on CCL8/CCR5 and JAK-STAT-driven CCL8 as tumor- and inflammation-promoting axes, including a CCL8/CCR5/mTORC1 metastatic loop and IFN-γ/JAK-STAT fibroblast induction.","evidence":"Lactate/M2 macrophage colorectal model with CCR5 knockdown; IFN-γ/peficitinib fibroblast RNA-seq; MSC-podocyte VCAM-1-dependent co-culture","pmids":["38136340","36672151","37567910"],"confidence":"Medium","gaps":["mTORC1 linkage to CCR5 mechanistically thin","Direct STAT binding to CCL8 promoter not shown in fibroblast study"]},{"year":2024,"claim":"In vivo gene editing established a non-immune role for CCL8 as an autocrine negative regulator of myogenic progenitor differentiation and muscle regeneration.","evidence":"AAV9 CRISPR depletion of Ccl8 in Pax7+/Myf5+/MyoD+ cells, barium chloride injury, and recombinant CCL8 rescue","pmids":["39051762"],"confidence":"High","gaps":["Receptor mediating myogenic inhibition not identified","Downstream signaling in progenitors undefined"]},{"year":2025,"claim":"A wave of mechanistic studies defined transcriptional and chromatin regulators of CCL8 (STAT1/HSP90, IRF1/JMJD1A, CBX6/SMARCD1, USP18/SOCS1) and its roles in macrophage-mediated tumor immune evasion, cardiomyocyte inflammation, and asthma.","evidence":"Conditional KO mice, ChIP, knockdown/inhibitor studies, and CCL8-receptor-targeted DTCCL8 cytotoxin across cancer, AF, asthma, and intestinal models","pmids":["39774471","41720180","41779805","41219497","41354823","40545574","41408455"],"confidence":"Medium","gaps":["Each regulatory axis from a single lab/context","Whether these converge on shared promoter elements unknown"]},{"year":2026,"claim":"Senescence-focused and therapy-context studies established CCL8 from P16+ cardiac cells as a driver of cytotoxic lymphocyte recruitment impairing repair, and chemotherapy-induced CCL8 as an NK-recruitment signal.","evidence":"p16-CreER dual-recombinase genetics with Ccl8 deletion and CD8 depletion in MI; MAPK-driven CCL8 chemotaxis with NK depletion in gastric cancer","pmids":["41766526","41843172"],"confidence":"High","gaps":["Receptor on recruited cytotoxic lymphocytes not specified in cardiac model","Translational relevance to human MI untested"]},{"year":null,"claim":"It remains unresolved which receptor mediates CCL8's many non-canonical, often autocrine effects (myogenesis, fibroblast ERK activation, cardiac and GVHD pathology) and how its diverse transcriptional/chromatin regulators integrate at the promoter.","evidence":"No single study in the timeline links these context-specific functions to a defined receptor or unified regulatory logic","pmids":[],"confidence":"Low","gaps":["Receptor for muscle/fibroblast effects unknown","No structural model of CCL8-receptor complexes","In vivo abundance and role of the CCL8(6-75) antagonist undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[0,7,9,17,22]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[5,14]}],"localization":[{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[0,1,14]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[17,19,21,32]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,7,9,14]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[0,3,4,5]}],"complexes":[],"partners":["CCR1","CCR2","CCR5","CCR8","CCR3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P80075","full_name":"C-C motif chemokine 8","aliases":["HC14","Monocyte chemoattractant protein 2","Monocyte chemotactic protein 2","MCP-2","Small-inducible cytokine A8"],"length_aa":99,"mass_kda":11.2,"function":"Chemotactic factor that attracts monocytes, lymphocytes, basophils and eosinophils. May play a role in neoplasia and inflammatory host responses. This protein can bind heparin. The processed form MCP-2(6-76) does not show monocyte chemotactic activity, but inhibits the chemotactic effect most predominantly of CCL7, and also of CCL2 and CCL5 and CCL8","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/P80075/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CCL8","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CCL8","total_profiled":1310},"omim":[{"mim_id":"605643","title":"KALLIKREIN-RELATED PEPTIDASE 5; KLK5","url":"https://www.omim.org/entry/605643"},{"mim_id":"604828","title":"CHEMOKINE, C MOTIF, LIGAND 2; XCL2","url":"https://www.omim.org/entry/604828"},{"mim_id":"602283","title":"CHEMOKINE, CC MOTIF, LIGAND 8; CCL8","url":"https://www.omim.org/entry/602283"},{"mim_id":"600250","title":"CHEMOKINE, C MOTIF, LIGAND 1; XCL1","url":"https://www.omim.org/entry/600250"},{"mim_id":"256500","title":"NETHERTON SYNDROME; NETH","url":"https://www.omim.org/entry/256500"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/CCL8"},"hgnc":{"alias_symbol":["MCP-2","HC14"],"prev_symbol":["SCYA8"]},"alphafold":{"accession":"P80075","domains":[{"cath_id":"2.40.50.40","chopping":"45-99","consensus_level":"medium","plddt":95.8515,"start":45,"end":99}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P80075","model_url":"https://alphafold.ebi.ac.uk/files/AF-P80075-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P80075-F1-predicted_aligned_error_v6.png","plddt_mean":88.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CCL8","jax_strain_url":"https://www.jax.org/strain/search?query=CCL8"},"sequence":{"accession":"P80075","fasta_url":"https://rest.uniprot.org/uniprotkb/P80075.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P80075/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P80075"}},"corpus_meta":[{"pmid":"11023497","id":"PMC_11023497","title":"Neutrophil gelatinase B potentiates interleukin-8 tenfold by aminoterminal processing, whereas it degrades CTAP-III, PF-4, and GRO-alpha and leaves RANTES and MCP-2 intact.","date":"2000","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/11023497","citation_count":546,"is_preprint":false},{"pmid":"1613466","id":"PMC_1613466","title":"Structural and functional identification of two human, tumor-derived monocyte chemotactic proteins (MCP-2 and MCP-3) belonging to the chemokine family.","date":"1992","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/1613466","citation_count":360,"is_preprint":false},{"pmid":"7926371","id":"PMC_7926371","title":"Monocyte chemotactic proteins MCP-1, MCP-2, and MCP-3 are major attractants for human CD4+ and CD8+ T lymphocytes.","date":"1994","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/7926371","citation_count":309,"is_preprint":false},{"pmid":"7531149","id":"PMC_7531149","title":"Actions of the chemotactic cytokines MCP-1, MCP-2, MCP-3, RANTES, MIP-1 alpha and MIP-1 beta on human monocytes.","date":"1995","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/7531149","citation_count":308,"is_preprint":false},{"pmid":"9655469","id":"PMC_9655469","title":"MCP-1, MCP-2 and MCP-3 expression in multiple sclerosis lesions: an immunohistochemical and in situ hybridization study.","date":"1998","source":"Journal of neuroimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/9655469","citation_count":307,"is_preprint":false},{"pmid":"21217759","id":"PMC_21217759","title":"Mouse CCL8, a CCR8 agonist, promotes atopic dermatitis by recruiting IL-5+ T(H)2 cells.","date":"2011","source":"Nature immunology","url":"https://pubmed.ncbi.nlm.nih.gov/21217759","citation_count":261,"is_preprint":false},{"pmid":"18684849","id":"PMC_18684849","title":"Evaluating the potential of IP-10 and MCP-2 as biomarkers for the diagnosis of tuberculosis.","date":"2008","source":"The European respiratory journal","url":"https://pubmed.ncbi.nlm.nih.gov/18684849","citation_count":156,"is_preprint":false},{"pmid":"14647058","id":"PMC_14647058","title":"Association of genetic variants of the chemokine receptor CCR5 and its ligands, RANTES and MCP-2, with outcome of HCV infection.","date":"2003","source":"Hepatology (Baltimore, Md.)","url":"https://pubmed.ncbi.nlm.nih.gov/14647058","citation_count":153,"is_preprint":false},{"pmid":"10502563","id":"PMC_10502563","title":"Expression of monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 by human airway smooth-muscle cells. Modulation by corticosteroids and T-helper 2 cytokines.","date":"1999","source":"American journal of respiratory cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/10502563","citation_count":122,"is_preprint":false},{"pmid":"9115216","id":"PMC_9115216","title":"Monocyte chemotactic protein-2 (MCP-2) uses CCR1 and CCR2B as its functional receptors.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9115216","citation_count":121,"is_preprint":false},{"pmid":"31263103","id":"PMC_31263103","title":"Hypoxia-induced ZEB1 promotes cervical cancer progression via CCL8-dependent tumour-associated macrophage recruitment.","date":"2019","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/31263103","citation_count":112,"is_preprint":false},{"pmid":"20181935","id":"PMC_20181935","title":"CCL8/MCP-2 is a target for mir-146a in HIV-1-infected human microglial cells.","date":"2010","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/20181935","citation_count":108,"is_preprint":false},{"pmid":"8189067","id":"PMC_8189067","title":"Induction of monocyte chemotactic proteins MCP-1 and MCP-2 in human fibroblasts and leukocytes by cytokines and cytokine inducers. Chemical synthesis of MCP-2 and development of a specific RIA.","date":"1994","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/8189067","citation_count":107,"is_preprint":false},{"pmid":"19193208","id":"PMC_19193208","title":"IP-10, MCP-1, MCP-2, MCP-3, and IL-1RA hold promise as biomarkers for infection with M. tuberculosis in a whole blood based T-cell assay.","date":"2009","source":"BMC research notes","url":"https://pubmed.ncbi.nlm.nih.gov/19193208","citation_count":100,"is_preprint":false},{"pmid":"15644410","id":"PMC_15644410","title":"TRAIL counteracts the proadhesive activity of inflammatory cytokines in endothelial cells by down-modulating CCL8 and CXCL10 chemokine expression and release.","date":"2005","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/15644410","citation_count":97,"is_preprint":false},{"pmid":"27471618","id":"PMC_27471618","title":"Maraviroc decreases CCL8-mediated migration of CCR5(+) regulatory T cells and reduces metastatic tumor growth in the lungs.","date":"2016","source":"Oncoimmunology","url":"https://pubmed.ncbi.nlm.nih.gov/27471618","citation_count":94,"is_preprint":false},{"pmid":"7535823","id":"PMC_7535823","title":"Monocyte chemotactic protein MCP-2 activates human basophil and eosinophil leukocytes similar to MCP-3.","date":"1995","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/7535823","citation_count":86,"is_preprint":false},{"pmid":"7514401","id":"PMC_7514401","title":"Human monocyte chemotactic proteins-2 and 3 (MCP-2 and MCP-3) attract human eosinophils and desensitize the chemotactic responses towards RANTES.","date":"1994","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/7514401","citation_count":79,"is_preprint":false},{"pmid":"27181207","id":"PMC_27181207","title":"A CCL8 gradient drives breast cancer cell dissemination.","date":"2016","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/27181207","citation_count":75,"is_preprint":false},{"pmid":"9790730","id":"PMC_9790730","title":"CCR5 has an expanded ligand-binding repertoire and is the primary receptor used by MCP-2 on activated T cells.","date":"1998","source":"Cellular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/9790730","citation_count":65,"is_preprint":false},{"pmid":"18256320","id":"PMC_18256320","title":"CCL8 is a potential molecular candidate for the diagnosis of graft-versus-host disease.","date":"2008","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/18256320","citation_count":61,"is_preprint":false},{"pmid":"19224633","id":"PMC_19224633","title":"Synergistic up-regulation of MCP-2/CCL8 activity is counteracted by chemokine cleavage, limiting its inflammatory and anti-tumoral effects.","date":"2009","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/19224633","citation_count":60,"is_preprint":false},{"pmid":"25253336","id":"PMC_25253336","title":"Latency-associated viral interleukin-10 (IL-10) encoded by human cytomegalovirus modulates cellular IL-10 and CCL8 Secretion during latent infection through changes in the cellular microRNA hsa-miR-92a.","date":"2014","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/25253336","citation_count":58,"is_preprint":false},{"pmid":"30841468","id":"PMC_30841468","title":"MiR-345-5p functions as a tumor suppressor in pancreatic cancer by directly targeting CCL8.","date":"2019","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/30841468","citation_count":55,"is_preprint":false},{"pmid":"28057004","id":"PMC_28057004","title":"Gene profile of fibroblasts identify relation of CCL8 with idiopathic pulmonary fibrosis.","date":"2017","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/28057004","citation_count":43,"is_preprint":false},{"pmid":"26320180","id":"PMC_26320180","title":"The importance of microenvironment: the role of CCL8 in metastasis formation of melanoma.","date":"2015","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/26320180","citation_count":43,"is_preprint":false},{"pmid":"12885941","id":"PMC_12885941","title":"Expression of L-CCR in HEK 293 cells reveals functional responses to CCL2, CCL5, CCL7, and CCL8.","date":"2003","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/12885941","citation_count":40,"is_preprint":false},{"pmid":"32768961","id":"PMC_32768961","title":"Possible involvement of crosstalk between endometrial cells and mast cells in the development of endometriosis via CCL8/CCR1.","date":"2020","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/32768961","citation_count":38,"is_preprint":false},{"pmid":"4051325","id":"PMC_4051325","title":"Newborn rabbit alveolar macrophages are deficient in two microbicidal cationic peptides, MCP-1 and MCP-2.","date":"1985","source":"The American review of respiratory disease","url":"https://pubmed.ncbi.nlm.nih.gov/4051325","citation_count":36,"is_preprint":false},{"pmid":"9119400","id":"PMC_9119400","title":"The human MCP-2 gene (SCYA8): cloning, sequence analysis, tissue expression, and assignment to the CC chemokine gene contig on chromosome 17q11.2.","date":"1997","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/9119400","citation_count":34,"is_preprint":false},{"pmid":"32535027","id":"PMC_32535027","title":"CCL8 Promotes Postpartum Breast Cancer by Recruiting M2 Macrophages.","date":"2020","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/32535027","citation_count":34,"is_preprint":false},{"pmid":"7780043","id":"PMC_7780043","title":"Chemical synthesis, purification and folding of the human monocyte chemotactic proteins MCP-2 and MCP-3 into biologically active chemokines.","date":"1995","source":"Cytokine","url":"https://pubmed.ncbi.nlm.nih.gov/7780043","citation_count":34,"is_preprint":false},{"pmid":"16988274","id":"PMC_16988274","title":"Cytokine and chemokine transcription profile during Mycoplasma pulmonis infection in susceptible and resistant strains of mice: macrophage inflammatory protein 1beta (CCL4) and monocyte chemoattractant protein 2 (CCL8) and accumulation of CCR5+ Th cells.","date":"2006","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/16988274","citation_count":33,"is_preprint":false},{"pmid":"29281969","id":"PMC_29281969","title":"Functional expression of CCL8 and its interaction with chemokine receptor CCR3.","date":"2017","source":"BMC immunology","url":"https://pubmed.ncbi.nlm.nih.gov/29281969","citation_count":32,"is_preprint":false},{"pmid":"9199875","id":"PMC_9199875","title":"Induction of gelatinase B and MCP-2 in baboons during sublethal and lethal bacteraemia.","date":"1997","source":"Cytokine","url":"https://pubmed.ncbi.nlm.nih.gov/9199875","citation_count":32,"is_preprint":false},{"pmid":"4091528","id":"PMC_4091528","title":"Cytotoxicity of rabbit macrophage peptides MCP-1 and MCP-2 for mouse tumor cells.","date":"1985","source":"Antimicrobial agents and chemotherapy","url":"https://pubmed.ncbi.nlm.nih.gov/4091528","citation_count":31,"is_preprint":false},{"pmid":"36672151","id":"PMC_36672151","title":"Pathogenic Th2 Cytokine Profile Skewing by IFN-γ-Responding Vitiligo Fibroblasts via CCL2/CCL8.","date":"2023","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/36672151","citation_count":30,"is_preprint":false},{"pmid":"29037608","id":"PMC_29037608","title":"Chemokine CCL8 and its receptor CCR5 in the spinal cord are involved in visceral pain induced by experimental colitis in mice.","date":"2017","source":"Brain research bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/29037608","citation_count":30,"is_preprint":false},{"pmid":"24477914","id":"PMC_24477914","title":"The transcriptional repressor BLIMP1 curbs host defenses by suppressing expression of the chemokine CCL8.","date":"2014","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/24477914","citation_count":30,"is_preprint":false},{"pmid":"23418602","id":"PMC_23418602","title":"Induction of CCL8/MCP-2 by mycobacteria through the activation of TLR2/PI3K/Akt signaling pathway.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23418602","citation_count":29,"is_preprint":false},{"pmid":"18981157","id":"PMC_18981157","title":"Oncostatin M-induced and constitutive activation of the JAK2/STAT5/CIS pathway suppresses CCL1, but not CCL7 and CCL8, chemokine expression.","date":"2008","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/18981157","citation_count":28,"is_preprint":false},{"pmid":"24958709","id":"PMC_24958709","title":"Allergic airway inflammation decreases lung bacterial burden following acute Klebsiella pneumoniae infection in a neutrophil- and CCL8-dependent manner.","date":"2014","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/24958709","citation_count":28,"is_preprint":false},{"pmid":"38136340","id":"PMC_38136340","title":"Lactate-Induced CCL8 in Tumor-Associated Macrophages Accelerates the Progression of Colorectal Cancer through the CCL8/CCR5/mTORC1 Axis.","date":"2023","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/38136340","citation_count":27,"is_preprint":false},{"pmid":"36136589","id":"PMC_36136589","title":"Iron accelerates Fusobacterium nucleatum-induced CCL8 expression in macrophages and is associated with colorectal cancer progression.","date":"2022","source":"JCI insight","url":"https://pubmed.ncbi.nlm.nih.gov/36136589","citation_count":25,"is_preprint":false},{"pmid":"29339207","id":"PMC_29339207","title":"Nicaraven reduces cancer metastasis to irradiated lungs by decreasing CCL8 and macrophage recruitment.","date":"2018","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/29339207","citation_count":25,"is_preprint":false},{"pmid":"30902794","id":"PMC_30902794","title":"CCL8 enhances sensitivity of cutaneous squamous cell carcinoma to photodynamic therapy by recruiting M1 macrophages.","date":"2019","source":"Photodiagnosis and photodynamic therapy","url":"https://pubmed.ncbi.nlm.nih.gov/30902794","citation_count":24,"is_preprint":false},{"pmid":"11044560","id":"PMC_11044560","title":"Cloning of equine chemokines eotaxin, monocyte chemoattractant protein (MCP)-1, MCP-2 and MCP-4, mRNA expression in tissues and induction by IL-4 in dermal fibroblasts.","date":"2000","source":"Veterinary immunology and immunopathology","url":"https://pubmed.ncbi.nlm.nih.gov/11044560","citation_count":24,"is_preprint":false},{"pmid":"20624948","id":"PMC_20624948","title":"Stromal cell-derived CXCL12 and CCL8 cooperate to support increased development of regulatory dendritic cells following Leishmania infection.","date":"2010","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/20624948","citation_count":23,"is_preprint":false},{"pmid":"23584443","id":"PMC_23584443","title":"Monitoring of TNFR1, IL-2Rα, HGF, CCL8, IL-8 and IL-12p70 following HSCT and their role as GVHD biomarkers in paediatric patients.","date":"2013","source":"Bone marrow transplantation","url":"https://pubmed.ncbi.nlm.nih.gov/23584443","citation_count":23,"is_preprint":false},{"pmid":"38528587","id":"PMC_38528587","title":"Single-cell RNA sequencing reveals recruitment of the M2-like CCL8high macrophages in Lewis lung carcinoma-bearing mice following hypofractionated radiotherapy.","date":"2024","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/38528587","citation_count":21,"is_preprint":false},{"pmid":"35973731","id":"PMC_35973731","title":"Blocking CCL8-CCR8-Mediated Early Allograft Inflammation Improves Kidney Transplant Function.","date":"2022","source":"Journal of the American Society of Nephrology : JASN","url":"https://pubmed.ncbi.nlm.nih.gov/35973731","citation_count":21,"is_preprint":false},{"pmid":"33833397","id":"PMC_33833397","title":"CCL8 mediates crosstalk between endothelial colony forming cells and triple-negative breast cancer cells through IL-8, aggravating invasion and tumorigenicity.","date":"2021","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/33833397","citation_count":21,"is_preprint":false},{"pmid":"11164897","id":"PMC_11164897","title":"Expression of the chemokines, monocyte chemotactic protein (MCP)-1 and MCP-2 in endometrium of normal women and Norplant users, does not support a central role in macrophage infiltration into endometrium.","date":"2001","source":"Journal of reproductive immunology","url":"https://pubmed.ncbi.nlm.nih.gov/11164897","citation_count":21,"is_preprint":false},{"pmid":"25764912","id":"PMC_25764912","title":"CCL8 and the Immune Control of Cytomegalovirus in Organ Transplant Recipients.","date":"2015","source":"American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons","url":"https://pubmed.ncbi.nlm.nih.gov/25764912","citation_count":17,"is_preprint":false},{"pmid":"29550454","id":"PMC_29550454","title":"MicroRNA-146a-5p attenuates visceral hypersensitivity through targeting chemokine CCL8 in the spinal cord in a mouse model of colitis.","date":"2018","source":"Brain research bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/29550454","citation_count":17,"is_preprint":false},{"pmid":"31423262","id":"PMC_31423262","title":"MicroRNA-181 inhibits glioblastoma cell growth by directly targeting CCL8.","date":"2019","source":"Oncology letters","url":"https://pubmed.ncbi.nlm.nih.gov/31423262","citation_count":14,"is_preprint":false},{"pmid":"22894773","id":"PMC_22894773","title":"Pseudogenization of the MCP-2/CCL8 chemokine gene in European rabbit (genus Oryctolagus), but not in species of Cottontail rabbit (Sylvilagus) and Hare (Lepus).","date":"2012","source":"BMC genetics","url":"https://pubmed.ncbi.nlm.nih.gov/22894773","citation_count":14,"is_preprint":false},{"pmid":"21782767","id":"PMC_21782767","title":"Early expression of plasma CCL8 closely correlates with survival rate of acute graft-vs.-host disease in mice.","date":"2011","source":"Experimental hematology","url":"https://pubmed.ncbi.nlm.nih.gov/21782767","citation_count":14,"is_preprint":false},{"pmid":"10496322","id":"PMC_10496322","title":"Transcriptional control of the human MCP-2 gene promoter by IFN-gamma and IL-1beta in connective tissue cells.","date":"1999","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/10496322","citation_count":14,"is_preprint":false},{"pmid":"32498476","id":"PMC_32498476","title":"CaSR Antagonist (Calcilytic) NPS 2143 Hinders the Release of Neuroinflammatory IL-6, Soluble ICAM-1, RANTES, and MCP-2 from Aβ-Exposed Human Cortical Astrocytes.","date":"2020","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/32498476","citation_count":14,"is_preprint":false},{"pmid":"40541814","id":"PMC_40541814","title":"Insights on the role of the chemokine CCL8 in pathology.","date":"2025","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/40541814","citation_count":12,"is_preprint":false},{"pmid":"36404927","id":"PMC_36404927","title":"Beneficial effects of CCL8 inhibition at lipopolysaccharide-induced lung injury.","date":"2022","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/36404927","citation_count":12,"is_preprint":false},{"pmid":"34391459","id":"PMC_34391459","title":"Pathogenic roles and therapeutic potential of the CCL8-CCR8 axis in a murine model of IgG4-related sialadenitis.","date":"2021","source":"Arthritis research & therapy","url":"https://pubmed.ncbi.nlm.nih.gov/34391459","citation_count":12,"is_preprint":false},{"pmid":"7999015","id":"PMC_7999015","title":"Porcine luteal cells express monocyte chemoattractant protein-2 (MCP-2): analysis by cDNA cloning and northern analysis.","date":"1994","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/7999015","citation_count":12,"is_preprint":false},{"pmid":"32307587","id":"PMC_32307587","title":"Evaluation of the inflammatory markers CCL8, CXCL5, and LIF in patients with anastomotic leakage after colorectal cancer surgery.","date":"2020","source":"International journal of colorectal disease","url":"https://pubmed.ncbi.nlm.nih.gov/32307587","citation_count":9,"is_preprint":false},{"pmid":"19302923","id":"PMC_19302923","title":"Upregulation of plasma CCL8 in mouse model of graft-vs-host disease.","date":"2009","source":"Experimental hematology","url":"https://pubmed.ncbi.nlm.nih.gov/19302923","citation_count":9,"is_preprint":false},{"pmid":"22987449","id":"PMC_22987449","title":"Janus kinase 2 and signal transducer and activator of transcription 3 activation is not essential for CCL3-, CCL5- or CCL8-induced chemotaxis.","date":"2012","source":"Cell biochemistry and function","url":"https://pubmed.ncbi.nlm.nih.gov/22987449","citation_count":8,"is_preprint":false},{"pmid":"37567910","id":"PMC_37567910","title":"Mesenchymal stem cells enhance CCL8 expression by podocytes in lupus-prone MRL.Faslpr mice.","date":"2023","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/37567910","citation_count":7,"is_preprint":false},{"pmid":"27306379","id":"PMC_27306379","title":"Adaptive Gene Loss? Tracing Back the Pseudogenization of the Rabbit CCL8 Chemokine.","date":"2016","source":"Journal of molecular evolution","url":"https://pubmed.ncbi.nlm.nih.gov/27306379","citation_count":7,"is_preprint":false},{"pmid":"39774471","id":"PMC_39774471","title":"Tumor-initiating cells escape tumor immunity via CCL8 from tumor-associated macrophages in mice.","date":"2025","source":"The Journal of clinical investigation","url":"https://pubmed.ncbi.nlm.nih.gov/39774471","citation_count":6,"is_preprint":false},{"pmid":"34788319","id":"PMC_34788319","title":"Serum levels of NLRC4 and MCP-2/CCL8 in patients with active Crohn's disease.","date":"2021","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/34788319","citation_count":6,"is_preprint":false},{"pmid":"19415413","id":"PMC_19415413","title":"CCL8/MCP-2 association analysis in patients with Alzheimer's disease and frontotemporal lobar degeneration.","date":"2009","source":"Journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/19415413","citation_count":6,"is_preprint":false},{"pmid":"34808257","id":"PMC_34808257","title":"CCL8 deficiency in the host abrogates early mortality of acute graft-versus-host disease in mice with dysregulated IL-6 expression.","date":"2021","source":"Experimental hematology","url":"https://pubmed.ncbi.nlm.nih.gov/34808257","citation_count":6,"is_preprint":false},{"pmid":"39051762","id":"PMC_39051762","title":"Muscle cell-derived Ccl8 is a negative regulator of skeletal muscle regeneration.","date":"2024","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/39051762","citation_count":5,"is_preprint":false},{"pmid":"30663558","id":"PMC_30663558","title":"Diagnostic Accuracy of Monocyte Chemotactic Protein (MCP)-2 as Biomarker in Response to PE35/PPE68 Proteins: A Promising Diagnostic Method for the Discrimination of Active and Latent Tuberculosis.","date":"2019","source":"Protein and peptide letters","url":"https://pubmed.ncbi.nlm.nih.gov/30663558","citation_count":5,"is_preprint":false},{"pmid":"35344629","id":"PMC_35344629","title":"Dexamethasone attenuated thoracic aortic aneurysm and dissection in vascular smooth muscle cell Tgfbr2-disrupted mice with CCL8 suppression.","date":"2022","source":"Experimental physiology","url":"https://pubmed.ncbi.nlm.nih.gov/35344629","citation_count":4,"is_preprint":false},{"pmid":"37532728","id":"PMC_37532728","title":"Identification of potent anti-Candida metabolites produced by the soft coral associated Streptomyces sp. HC14 using chemoinformatics.","date":"2023","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/37532728","citation_count":4,"is_preprint":false},{"pmid":"40545574","id":"PMC_40545574","title":"Chimeric diphtheria toxin-CCL8 cytotoxic peptide for breast cancer management.","date":"2025","source":"Molecular oncology","url":"https://pubmed.ncbi.nlm.nih.gov/40545574","citation_count":4,"is_preprint":false},{"pmid":"33902378","id":"PMC_33902378","title":"Association between the Genetic Polymorphisms of CCL2, CCL5, CCL8, CCR2, and CCR5 with Chronic Hepatitis C Virus Infection in the Chinese Han Population.","date":"2021","source":"Immunological investigations","url":"https://pubmed.ncbi.nlm.nih.gov/33902378","citation_count":4,"is_preprint":false},{"pmid":"32432500","id":"PMC_32432500","title":"Silencing CCL8 inhibited the proliferation and migration of PDGF-BB-stimulated human aortic smooth muscle cells.","date":"2020","source":"Bioscience, biotechnology, and biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/32432500","citation_count":3,"is_preprint":false},{"pmid":"36628560","id":"PMC_36628560","title":"CCL2, CCL8, CXCL12 chemokines in resectable non-small cell lung cancer (NSCLC).","date":"2023","source":"Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia","url":"https://pubmed.ncbi.nlm.nih.gov/36628560","citation_count":3,"is_preprint":false},{"pmid":"41251087","id":"PMC_41251087","title":"Spatiotemporal mapping reveals Ccl8hi macrophages as key drivers of testicular inflammaging.","date":"2025","source":"Clinical and translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/41251087","citation_count":2,"is_preprint":false},{"pmid":"40685774","id":"PMC_40685774","title":"Targeting NLRP1-CCL8 axis in the leukaemic niche suppresses AML via inhibition of PI3K-AKT signalling.","date":"2025","source":"British journal of haematology","url":"https://pubmed.ncbi.nlm.nih.gov/40685774","citation_count":2,"is_preprint":false},{"pmid":"38889138","id":"PMC_38889138","title":"Evaluation of serum MIP-1β and MCP-2 levels in major depressive disorder: A case-control study.","date":"2024","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/38889138","citation_count":2,"is_preprint":false},{"pmid":"34160019","id":"PMC_34160019","title":"Revisiting CCL-type chemokines in breast cancer and its milieu: prominent targetable chemokines, CCL8 and CCL21.","date":"2021","source":"Bioscience reports","url":"https://pubmed.ncbi.nlm.nih.gov/34160019","citation_count":2,"is_preprint":false},{"pmid":"41219497","id":"PMC_41219497","title":"CBX6 induces CD8+ T cell exhaustion and tumor development in esophageal squamous cell carcinoma through SMARCD1-mediated CCL8 secretion and lactate efflux.","date":"2025","source":"Cell biology and toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/41219497","citation_count":1,"is_preprint":false},{"pmid":"41155258","id":"PMC_41155258","title":"Checkpoint Blockade Efficacy in Uveal Melanoma Is Linked to Tumor Immunity, CD28, and CCL8.","date":"2025","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41155258","citation_count":1,"is_preprint":false},{"pmid":"41766526","id":"PMC_41766526","title":"P16+ Cells Drive Adverse Postischemic Cardiac Remodeling Through CCL8-Mediated Recruitment of Cytotoxic Lymphocytes.","date":"2026","source":"Circulation","url":"https://pubmed.ncbi.nlm.nih.gov/41766526","citation_count":0,"is_preprint":false},{"pmid":"41318072","id":"PMC_41318072","title":"Role of CCL8 in cancer immunity and tumor progression: Implications for cancer treatment.","date":"2025","source":"Biochimica et biophysica acta. Reviews on cancer","url":"https://pubmed.ncbi.nlm.nih.gov/41318072","citation_count":0,"is_preprint":false},{"pmid":"41408455","id":"PMC_41408455","title":"CCL8 suppresses ovarian cancer progression via M1 macrophage polarization and NF-κB-mediated apoptosis.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/41408455","citation_count":0,"is_preprint":false},{"pmid":"41354823","id":"PMC_41354823","title":"USP18 confers protection against allergic asthma by suppressing CCL8 production in alveolar type II epithelial cells.","date":"2025","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/41354823","citation_count":0,"is_preprint":false},{"pmid":"41779805","id":"PMC_41779805","title":"Histone demethylase JMJD1A protects mice from enteric bacterial infection by upregulating CCL8 expression to recruit macrophages and CD4+ T cells.","date":"2026","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/41779805","citation_count":0,"is_preprint":false},{"pmid":"41720180","id":"PMC_41720180","title":"Targeting HSP90 suppresses STAT1/CCL8-driven inflammation and mitigates mitochondrial dysfunction to attenuate hypertension-induced atrial fibrillation.","date":"2026","source":"Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41720180","citation_count":0,"is_preprint":false},{"pmid":"41843172","id":"PMC_41843172","title":"CCL8-dependent recruitment of natural killer cells enhances the antitumor activity of neoadjuvant chemotherapy in gastric cancer.","date":"2026","source":"Cancer immunology, immunotherapy : CII","url":"https://pubmed.ncbi.nlm.nih.gov/41843172","citation_count":0,"is_preprint":false},{"pmid":"42065919","id":"PMC_42065919","title":"Aging-Associated CCL8+ Senescent Macrophages Recruit CCR1+ Neutrophils to Promote NETs Formation and Impair Meningeal Lymphatic Drainage.","date":"2026","source":"Aging and disease","url":"https://pubmed.ncbi.nlm.nih.gov/42065919","citation_count":0,"is_preprint":false},{"pmid":"40661472","id":"PMC_40661472","title":"Extracellular vesicle-derived miR-425-5p (miR-425) activates astrocytes in the brain to promote breast cancer brain metastasis via the novel miR-425-ZNF24-CCL8 signaling axis.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40661472","citation_count":0,"is_preprint":false},{"pmid":"41977380","id":"PMC_41977380","title":"Breast Cancer-Derived Extracellular Vesicle miR-425-5p (miR-425) Promotes Brain Metastasis via Activating Astrocytes Through the Novel miR-425-ZNF24-CCL8 Signaling Axis.","date":"2026","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41977380","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.19.670635","title":"A Spatially Coordinated Keratinocyte-Fibroblast Circuit Recruits MMP9  <sup>+</sup>  Myeloid Cells to Drive IFN-I-Driven Inflammation in Photosensitive Autoimmunity","date":"2025-08-24","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.19.670635","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.10.08.681192","title":"Causal Modeling Reveals Cell-Cell Communication Dynamics in the Tumor Microenvironment During Anti-PD-1 Therapy in Breast Cancer Patients","date":"2025-10-14","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.08.681192","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.09.13.24313599","title":"A multi-omics bidirectional mendelian randomization study and meta-analysis on the causal relationship between gut microbiota, inflammatory proteins, and fibromyalgia.","date":"2024-09-14","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.13.24313599","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":54184,"output_tokens":12170,"usd":0.172551,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":23539,"output_tokens":6082,"usd":0.134873,"stage2_stop_reason":"end_turn"},"total_usd":0.307424,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1992,\n      \"finding\": \"CCL8/MCP-2 was isolated from cytokine-stimulated human osteosarcoma cells (MG-63), identified by peptide sequencing, and shown to specifically attract monocytes but not neutrophils in vitro and in vivo (intradermal injection in rabbits). It was classified as a CC chemokine with conserved cysteine residues, structurally related to MCP-1.\",\n      \"method\": \"Protein purification, peptide sequencing, chemotaxis assay (Boyden chamber), in vivo injection\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — direct biochemical isolation, sequencing, and functional chemotaxis assays; foundational characterization paper replicated by subsequent studies\",\n      \"pmids\": [\"1613466\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"Synthetic CCL8/MCP-2 (76-residue protein) was chemotactic for monocytes at 1 nM; IFN-γ was identified as a superior inducer of MCP-2 (compared to IL-1β for MCP-1) in fibroblasts, while granulocytes were inefficient producers. Regulation of MCP-1 and MCP-2 expression was shown to be non-identical.\",\n      \"method\": \"Chemical synthesis, radioimmunoassay (RIA), cytokine stimulation of human fibroblasts and leukocytes\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — synthetic protein validated biochemically, multiple cell types and inducers tested with quantitative assays\",\n      \"pmids\": [\"8189067\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"CCL8/MCP-2 induced migration of human CD4+ and CD8+ T lymphocytes with a bimodal concentration dependence, elicited cytosolic Ca2+ increases blocked by pertussis toxin (indicating G-protein-coupled receptor involvement), and desensitization experiments showed MCP-1, MCP-2, and MCP-3 share receptors on T cells.\",\n      \"method\": \"Chemotaxis assay, intracellular Ca2+ measurement, pertussis toxin treatment, receptor desensitization, radioligand binding\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal functional assays; receptor sharing confirmed by cross-desensitization and binding competition\",\n      \"pmids\": [\"7926371\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"CCL8/MCP-2 attracted human eosinophils (ED50 ~40 nM) and cross-desensitized eosinophil chemotactic responses to RANTES, indicating CCL8 and MCP-3 signal through the same receptor on eosinophils as RANTES.\",\n      \"method\": \"Boyden chamber eosinophil chemotaxis assay, cross-desensitization experiments\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional chemotaxis and desensitization in primary cells, single lab\",\n      \"pmids\": [\"7514401\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"CCL8/MCP-2 actions on human monocytes include bimodal migration, N-acetyl-β-D-glucosaminidase release, and Ca2+ transients. Cross-desensitization showed MCP-1, MCP-2, and MCP-3 share a receptor subgroup on monocytes distinct from the RANTES/MIP-1α/MIP-1β subgroup, though MCP-2 also partially interacts with the latter. Radiolabeled MCP-1 binding was competed by all MCPs; MCP-3 (but not MCP-1/MCP-2) fully displaced MIP-1α.\",\n      \"method\": \"Migration assay, exocytosis assay, Ca2+ measurement, cross-desensitization, radioligand binding competition\",\n      \"journal\": \"European journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods on primary human monocytes; receptor sharing established by reciprocal desensitization and binding\",\n      \"pmids\": [\"7531149\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"CCL8/MCP-2 induced mediator release in human basophils (lower efficacy than MCP-1/MCP-3), Ca2+ transients, and chemotaxis in both basophils and eosinophils. Desensitization studies indicated MCP-2 interacts with receptors recognizing both MCP-1 and RANTES. In IL-3-untreated basophils, MCP-2 acted as a functional inhibitor of other CC chemokine actions.\",\n      \"method\": \"Mediator release assay, Ca2+ measurement, chemotaxis assay, cross-desensitization\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal functional assays in primary cells demonstrating both agonist and antagonist activities\",\n      \"pmids\": [\"7535823\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"CCL8/MCP-2 and MCP-3 were chemically synthesized using Fmoc solid-phase chemistry, correctly folded with disulfide bridges in glutathione redox buffer, and shown to be chemotactic for monocytes at 7.5 ng/ml and 5 ng/ml respectively, equivalent to natural chemokines. Neither induced neutrophil chemotaxis.\",\n      \"method\": \"Solid-phase peptide synthesis, RP-HPLC purification, disulfide bridge formation, monocyte chemotaxis assay\",\n      \"journal\": \"Cytokine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution from synthetic protein with full biochemical validation and functional equivalence to natural protein\",\n      \"pmids\": [\"7780043\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"CCL8/MCP-2 uses CCR1 and CCR2B as functional receptors. 125I-MCP-2 bound to HEK293 cells transfected with CCR1 or CCR2B; binding was displaced by known CCR1/CCR2B ligands. Both CCR1- and CCR2B-transfected cells showed significant chemotactic migration in response to MCP-2.\",\n      \"method\": \"Radioiodinated ligand binding assay, receptor-transfected cell chemotaxis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct radioligand binding and functional migration assay on receptor-transfected cells; replicated by subsequent studies\",\n      \"pmids\": [\"9115216\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"The human MCP-2/CCL8 gene (SCYA8) was cloned and localized to chromosome 17q11.2 within the CC chemokine gene contig. The gene shares a conserved intron-exon structure with MCP-1 and MCP-3 genes. MCP-2 mRNA (1.0 kb) was predominantly detected in small intestine, peripheral blood, heart, placenta, lung, and other tissues.\",\n      \"method\": \"YAC contig PCR cloning, genomic sequencing, Northern blot analysis\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — direct genomic cloning and sequencing with Northern blot expression profiling\",\n      \"pmids\": [\"9119400\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"CCL8/MCP-2 binds CCR5 with high affinity and is a true CCR5 agonist, eliciting robust chemotaxis in CCR5 transfectants, cross-desensitization with RANTES on Ca2+ flux, and inhibiting M-tropic HIV-1 gp120 binding to CCR5 and HIV-1 infection of PBMCs. On activated CD3+/IL-2 T cells, CCL8-mediated chemotaxis was predominantly inhibited by anti-CCR5 mAb 2D7, establishing CCR5 as the primary receptor on these cells.\",\n      \"method\": \"Radioligand binding, chemotaxis of CCR5 transfectants, Ca2+ flux cross-desensitization, HIV-1 binding inhibition assay, anti-CCR5 mAb blocking\",\n      \"journal\": \"Cellular immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods including binding, functional migration, receptor blockade, and antiviral assays\",\n      \"pmids\": [\"9790730\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"The CCL8/MCP-2 gene promoter region between -340 and -301 (relative to transcription start site) is required for IFN-γ-induced transcription in fibroblasts and osteosarcoma cells. The region -143 to -73 (containing putative GATA-1, H-APF1, AP-1, and GAS elements) is important for basal transcription. IL-1β alone failed to induce expression, but synergized with IFN-γ in osteosarcoma cells. Transcription factors in nuclear extracts were shown to bind the -340/-301 region by EMSA.\",\n      \"method\": \"5'-deletion mutagenesis, luciferase reporter assay, electromobility shift assay (EMSA)\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — promoter deletion mutagenesis with luciferase readout plus EMSA; single lab but two orthogonal methods\",\n      \"pmids\": [\"10496322\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Neutrophil gelatinase B (MMP-9) does not digest CCL8/MCP-2 (or RANTES), in contrast to its processing of IL-8, CTAP-III, PF-4, and GRO-alpha. This establishes that CCL8 is resistant to MMP-9-mediated aminoterminal processing.\",\n      \"method\": \"In vitro protease digestion assay with purified gelatinase B\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — direct in vitro enzymatic assay with purified proteins; negative result for CCL8 is mechanistically informative\",\n      \"pmids\": [\"11023497\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"The orphan mouse chemokine receptor L-CCR expressed in HEK293 cells showed pertussis toxin-sensitive chemotaxis and intracellular Ca2+ transients in response to CCL8 (and CCL2, CCL5, CCL7). Biotinylated CCL2 bound L-CCR-expressing cells, and L-CCR-GFP fusion protein localized to cell membranes.\",\n      \"method\": \"Receptor transfection in HEK293, chemotaxis assay, Ca2+ measurement, pertussis toxin treatment, biotinylated ligand binding, GFP fusion protein localization\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — functional assays in transfected cells, single lab; radioligand binding not detected, limiting confidence\",\n      \"pmids\": [\"12885941\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"TRAIL pretreatment of endothelial cells abrogated TNF-α-mediated upregulation of CCL8 and CXCL10 mRNA, as identified by cDNA microarray. Addition of recombinant CCL8 plus CXCL10 to endothelial cultures completely restored the proadhesive activity of TNF-α, demonstrating that CCL8 contributes to leukocyte/endothelial adhesion. Both TRAIL-R1 and TRAIL-R2 contributed to this chemokine modulation.\",\n      \"method\": \"cDNA microarray, qPCR, recombinant protein rescue experiment, agonistic anti-TRAIL receptor antibodies\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — microarray identified CCL8 target; functional rescue with recombinant protein confirmed mechanistic role; single lab\",\n      \"pmids\": [\"15644410\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Intact CCL8/MCP-2(1-76) produced by fibroblasts is processed into CCL8(6-75) under synergistic IFN-γ + IL-1β (or TLR ligand) stimulation. The truncated isoform CCL8(6-75) lacked chemotactic activity for monocytes and had severely reduced capacity to increase intracellular Ca2+ via CCR1, CCR2, CCR3, and CCR5. However, CCL8(6-75) still blocked these receptors, induced CCR2 internalization, inhibited MCP-1/CCL2 and MCP-2/CCL8 ERK signaling, and antagonized chemotactic activity of several CCR2 ligands.\",\n      \"method\": \"Protein purification, N-terminal sequencing, Ca2+ flux assay, chemotaxis assay, receptor internalization assay, ERK phosphorylation assay\",\n      \"journal\": \"European journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — direct biochemical identification of cleavage product with multiple orthogonal functional readouts demonstrating agonist-to-antagonist conversion\",\n      \"pmids\": [\"19224633\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"CCL8/MCP-2 is a direct target of miR-146a in HIV-1-infected human microglial cells. Overexpression of miR-146a prevented HIV-induced secretion of MCP-2. In HIV-encephalitis brain samples, decreased MCP-2 levels coincided with increased miR-146a, suggesting post-transcriptional regulation of CCL8 by miR-146a during chronic neuroinflammation.\",\n      \"method\": \"miRNA overexpression, ELISA for MCP-2 secretion, HIV-1 infection of primary microglial cells, brain tissue analysis\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional overexpression experiment in primary cells with protein-level readout; mechanistic targeting confirmed but full luciferase validation not described in abstract\",\n      \"pmids\": [\"20181935\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Stromal cell-derived CCL8 cooperated with CXCL12 to attract hematopoietic progenitors capable of differentiating into regulatory dendritic cells. Leishmania donovani infection of murine bone marrow stromal cells enhanced CCL8 production and their capacity to support regulatory DC development. In experimental visceral leishmaniasis, CCL8 production was induced in splenic stromal cells.\",\n      \"method\": \"Hematopoietic progenitor migration assay, stromal cell infection, in vivo murine leishmaniasis model, DC differentiation assay\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional migration and differentiation assays with in vivo model; single lab\",\n      \"pmids\": [\"20624948\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Mouse CCL8 is a CCR8 agonist but not a CCR2 agonist, distinguishing it from all other MCP chemokines. CCL8-CCR8 signaling defines a population of highly differentiated CCR8-expressing inflammatory Th2 cells enriched for IL-5. Ccr8- and Ccl8-deficient mice had markedly less eosinophilic inflammation in a chronic atopic dermatitis model. Adoptive transfer studies established CCR8 as a key regulator of Th2 cell recruitment into allergen-inflamed skin.\",\n      \"method\": \"Receptor binding/signaling assays, Ccr8/Ccl8 knockout mice, chronic atopic dermatitis model, adoptive transfer studies, flow cytometry\",\n      \"journal\": \"Nature immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods including KO mice, adoptive transfer, and cell biology; replicated in human CCR8+ T cell subset\",\n      \"pmids\": [\"21217759\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Mycobacterium bovis BCG and M. tuberculosis H37Rv infection induced CCL8/MCP-2 production in macrophage cell lines and primary macrophages through TLR2/PI3K/Akt and p38 signaling pathways. CCR5 (primary receptor for MCP-2/CCL8) was predominantly expressed on pleural CD4+ T lymphocytes in TB patients, suggesting CCL8 mediates T lymphocyte recruitment in pleural TB.\",\n      \"method\": \"Mycobacterial infection of macrophages, signaling pathway inhibitors, qPCR, protein array, flow cytometry on patient samples\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pathway inhibitor experiments in multiple cell types; single lab, no genetic confirmation of TLR2 requirement\",\n      \"pmids\": [\"23418602\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"BLIMP1 is a direct transcriptional repressor of CCL8 in macrophages. BLIMP1-deficient macrophages expressed elevated Ccl8, and Blimp1 CKO mice had higher circulating CCL8 and increased neutrophils, promoting antibacterial responses. CCL8 was chemotactic for γ/δ T cells enriched for IL-17F, and CCL8-mediated clearance of Listeria monocytogenes was dependent on γ/δ T cells. CCL8 failed to recruit neutrophils directly.\",\n      \"method\": \"Conditional knockout mice (Blimp1 CKO in myeloid cells), transcriptome analysis, Ccl8 knockout mice, Listeria infection model, chemotaxis assay, γ/δ T cell depletion\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO with transcriptomics, Ccl8 KO mice, infection model, and cell depletion experiments; multiple orthogonal approaches\",\n      \"pmids\": [\"24477914\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"LAcmvIL-10 (HCMV latency-associated viral IL-10) is responsible for increased CCL8 secretion from latently infected myeloid progenitors. This occurs through LAcmvIL-10-mediated suppression of cellular microRNA hsa-miR-92a, which directly targets CCL8. Downregulation of hsa-miR-92a thus upregulates CCL8 during HCMV latency.\",\n      \"method\": \"Latent infection of primary myeloid progenitors, miRNA expression analysis, secretome analysis\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional viral gene expression experiments linking viral protein to miRNA to CCL8; single lab\",\n      \"pmids\": [\"25253336\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CCL8 is produced by F4/80+ macrophages in the lungs of mice with metastatic primary tumors and drives CCR5-dependent Treg migration. Ex vivo Treg migration toward CCL8 was reduced by CCR5 inhibitor Maraviroc. Maraviroc treatment reduced CCR5+ Tregs and metastatic tumor burden in lungs, establishing a CCL8/CCR5 signaling axis for Treg recruitment.\",\n      \"method\": \"Ex vivo migration assay, flow cytometry, Maraviroc treatment, immunofluorescence, in vivo metastasis model\",\n      \"journal\": \"Oncoimmunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional migration assay with pharmacological inhibition and in vivo validation; single lab\",\n      \"pmids\": [\"27471618\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Recombinant CCL8 produced in E. coli binds CCR3 with a dissociation equilibrium constant (KD) of 1.2 × 10-7 M as measured by quartz crystal microbalance. CCL8 induced internalization of CCR3 in vivo within 1 hour at 100 nM and elicited weaker chemotactic effects in CCR3-expressing cells compared to CCL11 and CCL24.\",\n      \"method\": \"Recombinant protein production, quartz crystal microbalance binding assay, receptor internalization assay, chemotaxis assay\",\n      \"journal\": \"BMC immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — direct in vitro binding assay with defined KD and functional internalization assay; single lab\",\n      \"pmids\": [\"29281969\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"CCL8 expression in spinal neurons (co-localized with NeuN marker) was upregulated following TNBS-induced colonic inflammation. Intrathecal CCL8 neutralizing antibody or CCR5 antagonist DAPTA dose-dependently suppressed TNBS-evoked visceral hyperalgesia and spinal ERK activation, establishing a CCL8/CCR5/ERK pathway in spinal cord visceral pain maintenance.\",\n      \"method\": \"TNBS colitis model, immunohistochemistry, qPCR/Western blot, intrathecal antibody/antagonist injection, colorectal distension pain assay, ERK phosphorylation analysis\",\n      \"journal\": \"Brain research bulletin\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological blockade with defined pathway readout in vivo; single lab\",\n      \"pmids\": [\"29037608\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"miR-146a-5p directly targets the 3'-UTR of CCL8, as confirmed by dual-luciferase reporter assay. In Neuro-2a cells, TNF-α-induced CCL8 upregulation was decreased by miR-146a-5p mimic. Intrathecal miR-146a-5p agomir reduced CCL8 expression and relieved visceral pain in colitis mice; intrathecal antagomir upregulated CCL8 and induced pain hypersensitivity that was partially rescued by CCL8 neutralization.\",\n      \"method\": \"Dual-luciferase reporter assay, miRNA mimic/inhibitor transfection, intrathecal injection, TNBS colitis model, pain threshold measurement\",\n      \"journal\": \"Brain research bulletin\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — luciferase 3'-UTR validation plus in vivo gain/loss of function with rescue experiment; single lab but multiple orthogonal approaches\",\n      \"pmids\": [\"29550454\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Hypoxia-induced ZEB1 activates CCL8 transcription in cervical cancer cells, which attracts macrophages via the CCR2-NF-κB pathway. ZEB1 knockdown altered expression of multiple chemokines with CCL8 being most affected, and CCL8-dependent macrophage migration was demonstrated in vitro.\",\n      \"method\": \"Hypoxia treatment, ZEB1 knockdown/overexpression, chemokine expression profiling, macrophage migration assay, CCR2-NF-κB pathway analysis\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain/loss of function with defined pathway; single lab, in vitro mechanism\",\n      \"pmids\": [\"31263103\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"miR-345-5p directly targets CCL8 (confirmed by luciferase assay) and inversely correlates with CCL8 expression in PDAC samples. CCL8 activates the NF-κB signaling pathway to promote proliferation and invasiveness of pancreatic cancer cells.\",\n      \"method\": \"Luciferase reporter assay, miRNA overexpression, Western blot for NF-κB pathway, Transwell invasion assay\",\n      \"journal\": \"Biomedicine & pharmacotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — luciferase 3'-UTR validation and pathway analysis; single lab\",\n      \"pmids\": [\"30841468\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CCL8 promotes migratory ability of endometrial epithelial and stromal cells and increases proliferation, migration, and tube formation of endothelial cells through CCR1. CCR1, overexpressed in ectopic endometrium and co-localized with blood vessels, when inhibited suppressed endometriosis development and angiogenesis in vivo. CCL8 was upregulated in mast cells when co-cultured with endometrial cells.\",\n      \"method\": \"Co-culture system, Transwell migration assay, CCK-8 proliferation assay, tube formation assay, CCR1 inhibition in vivo mouse model\",\n      \"journal\": \"Biomedicine & pharmacotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional assays in vitro and in vivo with CCR1 inhibitor; single lab\",\n      \"pmids\": [\"32768961\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CCL8 is highly expressed during mammary gland involution and enhances infiltration of M2 subtype macrophages at the second phase of involution. In Ccl8-deficient animals, CCL8 accelerated tumor onset during involution but not in nulliparous animals. Macrophage depletion abolished the tumor-promoting effect of CCL8, establishing that CCL8 promotes postpartum breast cancer by recruiting M2 macrophages.\",\n      \"method\": \"Ccl8-deficient mice, cancer cell inoculation studies, macrophage depletion, immunohistochemistry\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mice with macrophage depletion rescue experiment; multiple orthogonal approaches confirming mechanism\",\n      \"pmids\": [\"32535027\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CCL8 from endothelial colony forming cells (ECFCs) induces IL-8 secretion from TNBC cells via c-Jun as a transcription factor. A positive feedback loop between CCL8 and IL-8 contributes to invasion, migration, MMP-2 secretion, and angiogenesis. CCL8 was crucial for ECFC-induced invasion of MDA-MB-231 cells.\",\n      \"method\": \"Indirect co-culture, cytokine antibody array, RT-PCR, siRNA knockdown, xenograft model, transcription factor identification\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional co-culture with knockdown and in vivo validation; single lab\",\n      \"pmids\": [\"33833397\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CCL8 plays a major role in acute GVHD pathogenesis. CCL8-knockout mice showed markedly reduced mortality (23.4% vs. 90% in wild-type) and attenuated liver dysfunction after allogeneic bone marrow transplantation. CCL8 deficiency was associated with a surge in plasma IL-6 in allograft recipients, suggesting CCL8 involvement in an IL-6 signaling cascade during aGVHD.\",\n      \"method\": \"CCL8 knockout mice, allogeneic bone marrow transplantation, survival analysis, plasma cytokine measurement, histopathology\",\n      \"journal\": \"Experimental hematology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO with clear phenotypic outcome and cytokine pathway identification; single lab but definitive genetic evidence\",\n      \"pmids\": [\"34808257\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Iron augmented Fusobacterium nucleatum-induced CCL8 expression in macrophages via TLR4/NF-κB signaling. Mechanistically, iron attenuated inhibitory phosphorylation of NF-κB p65 by activating serine/threonine phosphatases, thereby augmenting tumor-promoting chemokine production.\",\n      \"method\": \"qRT-PCR, Western blot, NF-κB signaling analysis, iron deficiency/supplementation experiments\",\n      \"journal\": \"JCI insight\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic signaling pathway identified with biochemical validation; single lab\",\n      \"pmids\": [\"36136589\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Donor kidney resident macrophages rapidly induced Ccl8 expression within 3 days post-transplant, which promoted recipient monocyte graft infiltration and their differentiation to resident macrophages, which in turn also expressed Ccl8. CCL8-CCR8 signaling then enhanced CCR8+ T cell (CD4, CD8, γδ) infiltration. Blocking CCL8-CCR8 or depleting donor kidney resident macrophages significantly inhibited early allograft immune cell infiltration and improved short-term function.\",\n      \"method\": \"Allogeneic murine kidney transplant model, CCL8-CCR8 blockade, macrophage depletion, flow cytometry, single-cell analysis\",\n      \"journal\": \"Journal of the American Society of Nephrology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic/pharmacological blockade in vivo with functional outcome; multiple cell populations characterized\",\n      \"pmids\": [\"35973731\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Lactate induced M2 macrophage polarization via AKT/ERK signaling pathway; M2 macrophages subsequently secreted CCL8 which facilitated colorectal cancer cell proliferation and metastasis by activating the CCL8/CCR5/mTORC1 axis. CCR5 antagonism or knockdown inhibited this protumorigenic effect.\",\n      \"method\": \"qRT-PCR, Western blot, RNA-seq, wound healing assay, colony formation assay, CCR5 knockdown/antagonist, allograft mouse model\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CCR5 genetic knockdown and pharmacological inhibition with in vivo validation; single lab\",\n      \"pmids\": [\"38136340\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"IFN-γ stimulation of fibroblasts via JAK-STAT signaling upregulated CCL2 and CCL8 expression. CCL2 addition to naïve T cell polarization promoted type 2 cytokine secretion. JAK inhibitor peficitinib abrogated IFN-γ-induced CCL2 and CCL8 upregulation in fibroblasts.\",\n      \"method\": \"RNA sequencing of vitiligo mouse model fibroblasts, JAK inhibitor treatment, qPCR, Western blot, T cell polarization assay, flow cytometry\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — JAK-STAT pathway identified with pharmacological validation; single lab\",\n      \"pmids\": [\"36672151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"MSCs enhanced CCL8 expression by podocytes in a contact-dependent manner (blocked by anti-VCAM-1 antibody, shown by transwell assay). Conversely, podocyte-derived CCL8 potentiated immunosuppressive activity of MSCs (increased IL-10, IDO, TGF-β1, iNOS production and stronger inhibition of IFN-γ by T cells).\",\n      \"method\": \"Co-culture, transwell assay, anti-VCAM-1 antibody blocking, qPCR/Western blot, T cell suppression assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — contact-dependent mechanism established with blocking antibody; bidirectional functional readouts; single lab\",\n      \"pmids\": [\"37567910\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Muscle cell-derived Ccl8 (from Pax7+, Myf5+, or MyoD+ myogenic progenitor cells) negatively regulates skeletal muscle regeneration. CRISPR-based depletion of Ccl8 in Pax7+ MPCs accelerated muscle regeneration after injury in both young and middle-aged mice. Intramuscular administration of recombinant Ccl8 reversed this accelerated regeneration phenotype, establishing Ccl8 as a negative regulator of myogenic differentiation initiation.\",\n      \"method\": \"Ccl8 knockdown in C2C12 myoblasts, AAV9-delivered sgRNA/Cas9 in vivo gene editing in Pax7+/Myf5+/MyoD+ cells, barium chloride injury model, recombinant CCL8 rescue\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo conditional gene editing with recombinant protein rescue in multiple MPC lineages; multiple orthogonal approaches\",\n      \"pmids\": [\"39051762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CCL8 is identified as a critical mediator downstream of GAS6/AXL/MERTK signaling in tumor-associated macrophages (Reg-TAMs) that facilitates immune escape of tumor-initiating cells primarily by inhibiting Treg infiltration into the tumor. AXL/MERTK inhibition reactivated antitumor immunity and sensitized tumor cells to anti-PD-1 treatment.\",\n      \"method\": \"scRNA-seq, lineage tracing, chemical inhibitors, Axl/Mertk conditional double-KO mice, anti-PD-1 combination studies\",\n      \"journal\": \"The Journal of clinical investigation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional KO with scRNA-seq and functional immunological readouts; single lab\",\n      \"pmids\": [\"39774471\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP18 stabilizes SOCS1 by inhibiting its ubiquitination and degradation, leading to reduced CCL8 production in AT2 cells through the ERK-STAT3 signaling pathway. USP18 deficiency increased CCL8 in AT2 cells, recruiting Th2 cells and eosinophils to exacerbate allergic asthma. CCL8 knockdown in AT2 cells of USP18 KO mice alleviated asthma symptoms.\",\n      \"method\": \"USP18 KO mice, AT2 cell-specific CCL8 knockdown, exogenous CCL8 treatment, SOCS1 ubiquitination assay, ERK-STAT3 pathway analysis\",\n      \"journal\": \"Respiratory research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with pathway mechanistic analysis and CCL8 knockdown rescue; single lab\",\n      \"pmids\": [\"41354823\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DTCCL8, a chimeric diphtheria toxin-CCL8 cytotoxic peptide, was developed to ablate cells expressing CCL8 receptors (particularly CCR5). Its specificity was confirmed in vitro by testing cytotoxic activity on CCR5-overexpressing breast cancer cells and by neutralizing anti-CCL8 antibody. In vivo, DTCCL8 showed anticancer activity in polyoma middle T oncogene-driven mouse breast cancers.\",\n      \"method\": \"Chimeric protein construction, in vitro cytotoxicity on CCR5-expressing cells, anti-CCL8 neutralizing antibody, in vivo mouse breast cancer model\",\n      \"journal\": \"Molecular oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro and in vivo functional validation of CCL8-receptor targeting; single lab\",\n      \"pmids\": [\"40545574\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"HSP90 interacts with transcription factor STAT1 and stabilizes its expression, driving CCL8 expression in atrial cardiomyocytes. CCL8 mediates macrophage recruitment and local atrial inflammation in hypertension-induced atrial fibrillation. STAT1 knockdown attenuated CCL8 upregulation and the inflammatory cascade.\",\n      \"method\": \"RNA sequencing, AngII-induced AF mouse model, HSP90 inhibitor (17AAG), STAT1 knockdown, Western blot, co-IP (HSP90-STAT1 interaction inferred)\",\n      \"journal\": \"Life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — STAT1 KD with in vivo model and HSP90 inhibitor; mechanistic link established but co-IP confirmation not explicitly described in abstract\",\n      \"pmids\": [\"41720180\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"JMJD1A (KDM3A) promotes CCL8 expression in colonic epithelial cells by demethylating H3K9me2 on both the IRF1 promoter (cooperating with STAT1 to upregulate IRF1) and the CCL8 promoter directly (cooperating with IRF1). CCL8 mediates recruitment of macrophages and CD4+ T cells, and JMJD1A-/- mice showed impaired CCL8 induction and reduced immune cell recruitment after C. rodentium infection.\",\n      \"method\": \"JMJD1A knockout mice, C. rodentium infection model, ChIP for H3K9me2, promoter analysis, flow cytometry for immune cell recruitment\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO mice with ChIP-based epigenetic mechanism; single lab\",\n      \"pmids\": [\"41779805\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CBX6 promotes CCL8 expression in esophageal squamous cell carcinoma cells through SMARCD1-mediated chromatin remodeling. CBX6 regulated SMARCD1 expression to modulate chromatin remodeling, thereby promoting CCL8 transcription. CCL8 secretion contributed to CD8+ T cell exhaustion and reduced cytotoxicity.\",\n      \"method\": \"Cbx6 knockdown, SMARCD1 overexpression, co-culture with CD8+ T cells, in vivo tumorigenesis model, tissue microarray\",\n      \"journal\": \"Cell biology and toxicology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic knockdown with in vivo validation and chromatin remodeling mechanism; single lab\",\n      \"pmids\": [\"41219497\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"P16+ fibroblasts and macrophages after myocardial infarction are the main sources of CCL8 in the heart. CCL8 blockade or genetic deletion of Ccl8 in P16+ cells reduced infiltration of cytotoxic lymphocytes (CD8+ T cells and NK cells), decreased cardiomyocyte apoptosis, and enhanced cardiac repair. Ablation of P16+ fibroblasts (but not macrophages) diminished fibrosis.\",\n      \"method\": \"p16-CreER reporter mice, dasatinib/quercetin senolytic treatment, bulk and scRNA-seq of P16+ cells, CCL8 neutralization, Ccl8 deletion in P16+ cells, CD8+ T cell depletion, dual-recombinase intersectional genetics\",\n      \"journal\": \"Circulation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional genetic deletion, neutralization antibody, cell depletion, and dual-recombinase lineage tools; multiple orthogonal approaches confirming CCL8 mechanism\",\n      \"pmids\": [\"41766526\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Recombinant mouse CCL8 stimulation of NIH/3T3 fibroblasts significantly increased collagen expression and ERK1/2 phosphorylation, suggesting CCL8 drives fibrosis via ERK1/2 phosphorylation. Anti-CCL8 neutralizing antibody improved focus and fibrosis scores in an IgG4-related sialadenitis mouse model (LAT Y136F knockin mice).\",\n      \"method\": \"Recombinant CCL8 stimulation of fibroblasts, Western blot for ERK1/2 phosphorylation, collagen expression assay, anti-CCL8 antibody treatment in vivo\",\n      \"journal\": \"Arthritis research & therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro signaling pathway with in vivo antibody blockade; single lab\",\n      \"pmids\": [\"34391459\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CCL8 induced M1 macrophage polarization in THP1-derived macrophages; conditioned medium from these macrophages suppressed ovarian cancer cell proliferation, migration, invasion, and EMT. Mechanistically, CCL8-induced macrophages promoted apoptosis in OC cells via activation of the NF-κB p65 pathway (increased Bax and Caspase3), which was reversed by p65 inhibition.\",\n      \"method\": \"Macrophage polarization assay, conditioned medium transfer, NF-κB inhibition, Western blot for apoptosis markers, proliferation/invasion assays\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pathway inhibition rescue experiment with functional readouts; single lab\",\n      \"pmids\": [\"41408455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Neoadjuvant chemotherapy activates the MAPK pathway in gastric cancer cells, inducing CCL8 secretion which facilitates NK cell recruitment. In vitro, NACT-treated tumor cells showed enhanced chemotactic effects on NK92 cells, and NACT-induced CCL8 was identified as the mechanistic driver of NK cell recruitment.\",\n      \"method\": \"In vitro NACT treatment, chemotaxis assay, MAPK pathway analysis, in vivo NK cell depletion\",\n      \"journal\": \"Cancer immunology, immunotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — MAPK pathway identified with functional chemotaxis assay and NK depletion in vivo; single lab\",\n      \"pmids\": [\"41843172\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CCL8/MCP-2 is a secreted CC chemokine that signals through multiple receptors (CCR1, CCR2B, CCR3, CCR5, and CCR8 in mice) via pertussis toxin-sensitive G-protein-coupled pathways to attract monocytes, T cells, basophils, eosinophils, and NK cells; its transcription is induced by IFN-γ via a promoter element at -340/-301 (and synergistically by IL-1β), repressed by BLIMP1 and miR-146a/miR-92a, and can be processed from active CCL8(1-76) into a receptor-blocking antagonist form CCL8(6-75); in disease contexts CCL8 drives Th2 inflammation through the CCL8-CCR8 axis, promotes macrophage and Treg recruitment in tumors, drives fibrosis via ERK1/2 in fibroblasts, mediates visceral pain through spinal CCR5/ERK signaling, acts as a negative regulator of muscle regeneration from myogenic progenitors, and orchestrates post-myocardial infarction remodeling through P16+ cell-derived CCL8-dependent cytotoxic lymphocyte recruitment.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CCL8/MCP-2 is a secreted CC chemokine that orchestrates leukocyte recruitment across inflammation, infection, fibrosis, and tumor immunity by signaling through multiple G-protein-coupled receptors [#0, #2]. Originally isolated from cytokine-stimulated osteosarcoma cells as a monocyte-specific chemoattractant structurally related to MCP-1, it also recruits CD4+ and CD8+ T lymphocytes, eosinophils, and basophils via pertussis toxin-sensitive, calcium-mobilizing signaling [#0, #2, #3, #5]. CCL8 is functionally promiscuous, acting as an agonist at CCR1 and CCR2B [#7], CCR5 [#9], and CCR3 [#22], with cross-desensitization establishing overlapping receptor usage shared with MCP-1, MCP-3, and RANTES on monocytes and eosinophils [#3, #4]; in mice CCL8 uniquely activates CCR8 rather than CCR2, defining a CCL8-CCR8 axis that recruits inflammatory Th2 cells and drives eosinophilic skin inflammation [#17]. The mature CCL8(1-76) protein is proteolytically converted under synergistic IFN-\\u03b3 plus IL-1\\u03b2/TLR stimulation into CCL8(6-75), which loses agonist activity yet retains the ability to block CCR1/2/3/5, internalize CCR2, and antagonize ERK signaling and chemotaxis\\u2014an agonist-to-antagonist switch\\u2014while remaining resistant to MMP-9 processing [#11, #14]. Its expression is induced by IFN-\\u03b3 through a -340/-301 promoter element and JAK-STAT signaling [#10, #34], by NF-\\u03baB downstream of TLR2/TLR4 microbial sensing [#18, #31], and by chromatin and transcription factor regulators including ZEB1, STAT1, IRF1/JMJD1A, and CBX6/SMARCD1 [#25, #40, #41, #42], and is repressed transcriptionally by BLIMP1 and post-transcriptionally by miR-146a and miR-92a [#19, #15, #20, #24]. Through these axes CCL8 recruits immunosuppressive and cytotoxic cells in disease: it drives macrophage and Treg recruitment to promote tumor growth and metastasis [#21, #28], mediates allograft rejection and acute GVHD [#30, #32], drives ERK1/2-dependent fibroblast collagen production in fibrosis [#44], maintains spinal CCR5/ERK visceral pain signaling [#23, #24], negatively regulates myogenic muscle regeneration [#36], and is produced by P16+ senescent fibroblasts and macrophages after myocardial infarction to recruit cytotoxic lymphocytes and impair cardiac repair [#43].\",\n  \"teleology\": [\n    {\n      \"year\": 1992,\n      \"claim\": \"Establishing that a distinct MCP-1-related CC chemokine existed answered whether a separate monocyte-selective chemoattractant could be biochemically purified and functionally defined.\",\n      \"evidence\": \"Protein purification, peptide sequencing, and chemotaxis from cytokine-stimulated osteosarcoma cells\",\n      \"pmids\": [\"1613466\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No receptor identified\", \"Cell selectivity beyond monocytes/neutrophils unexplored\"]\n    },\n    {\n      \"year\": 1994,\n      \"claim\": \"Synthetic protein and cytokine-induction studies established CCL8's intrinsic chemotactic potency and that its regulation diverges from MCP-1, with IFN-\\u03b3 as the superior inducer.\",\n      \"evidence\": \"Chemical synthesis, RIA, and cytokine stimulation of fibroblasts/leukocytes; T-cell chemotaxis with pertussis-toxin-sensitive Ca2+ flux\",\n      \"pmids\": [\"8189067\", \"7926371\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific receptor identity not resolved\", \"Mechanism of differential regulation versus MCP-1 unknown\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Cross-desensitization across leukocyte types resolved the question of CCL8 receptor usage, showing it shares receptor subgroups with MCP-1/MCP-3 and partially with RANTES, and can act as a functional inhibitor on basophils.\",\n      \"evidence\": \"Chemotaxis, Ca2+, mediator-release and radioligand competition on primary monocytes, eosinophils, and basophils\",\n      \"pmids\": [\"7531149\", \"7535823\", \"7514401\", \"7780043\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor identities defined only by cross-competition, not molecular cloning\", \"Basis of agonist versus inhibitor behavior unclear\"]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Receptor-transfection binding assays identified the molecular receptors CCR1 and CCR2B, converting inferred receptor sharing into defined ligand-receptor pairs, alongside genomic cloning to chromosome 17q11.2.\",\n      \"evidence\": \"Radioiodinated ligand binding and chemotaxis on CCR1/CCR2B-transfected HEK293 cells; YAC contig cloning and Northern blot\",\n      \"pmids\": [\"9115216\", \"9119400\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative contribution of each receptor in vivo unknown\", \"Tissue-specific receptor coupling not addressed\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Demonstration of high-affinity CCR5 agonism resolved CCL8's primary receptor on activated T cells and revealed an antiviral capacity by blocking M-tropic HIV-1 entry.\",\n      \"evidence\": \"Radioligand binding, CCR5-transfectant chemotaxis, anti-CCR5 mAb blockade, and HIV-1 gp120 binding/infection inhibition\",\n      \"pmids\": [\"9790730\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo relevance of HIV inhibition untested\", \"CCR5 signaling output not detailed\"]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Promoter dissection answered how IFN-\\u03b3 drives CCL8 transcription, mapping an inducible -340/-301 element and a basal -143/-73 region with IL-1\\u03b2 synergy.\",\n      \"evidence\": \"5'-deletion luciferase reporters and EMSA in fibroblasts/osteosarcoma cells\",\n      \"pmids\": [\"10496322\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the -340/-301 binding factors not established\", \"STAT involvement inferred, not proven at this stage\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Protease specificity testing established that CCL8 resists MMP-9 N-terminal processing, distinguishing its post-translational regulation from CXC chemokines.\",\n      \"evidence\": \"In vitro digestion with purified gelatinase B\",\n      \"pmids\": [\"11023497\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Other processing proteases not surveyed here\", \"Functional consequence of resistance unaddressed\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Identification of the CCL8(6-75) cleavage product answered how CCL8 activity is switched off and inverted, converting an agonist into a multi-receptor antagonist that blocks ERK and chemotaxis.\",\n      \"evidence\": \"Protein purification, N-terminal sequencing, Ca2+ flux, chemotaxis, receptor internalization, and ERK assays\",\n      \"pmids\": [\"19224633\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the processing protease not determined\", \"In vivo abundance of antagonist form unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Discovery of miR-146a and miR-92a targeting CCL8 established post-transcriptional control during viral infection, complementing transcriptional regulation.\",\n      \"evidence\": \"miRNA overexpression with ELISA in HIV-infected microglia; HCMV latency secretome and miRNA analysis in myeloid progenitors\",\n      \"pmids\": [\"20181935\", \"25253336\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct 3'-UTR binding not fully validated in 2010 microglial study\", \"Generalizability across cell types unknown\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Knockout and adoptive-transfer studies defined the mouse CCL8-CCR8 axis as a Th2-recruitment pathway, revealing receptor specificity distinct from all other MCPs.\",\n      \"evidence\": \"Ccl8/Ccr8 knockout mice, atopic dermatitis model, adoptive transfer, flow cytometry\",\n      \"pmids\": [\"21217759\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Human CCR8 agonism by CCL8 not equally established\", \"Upstream inducers of CCL8 in skin not defined here\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Genetic studies identified BLIMP1 as a direct transcriptional repressor of CCL8 and linked CCL8 to \\u03b3\\u03b4 T-cell-dependent antibacterial defense, defining a repression-controlled effector arm.\",\n      \"evidence\": \"Blimp1 conditional KO, Ccl8 KO, Listeria infection, chemotaxis, and \\u03b3\\u03b4 T-cell depletion\",\n      \"pmids\": [\"24477914\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct BLIMP1 binding site on Ccl8 not mapped\", \"Receptor mediating \\u03b3\\u03b4 recruitment not identified\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Tumor studies established a CCL8/CCR5 axis recruiting regulatory T cells, framing CCL8 as a driver of an immunosuppressive metastatic niche.\",\n      \"evidence\": \"Ex vivo Treg migration, Maraviroc CCR5 blockade, and in vivo lung metastasis model\",\n      \"pmids\": [\"27471618\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Maraviroc effects not CCL8-specific\", \"Source-cell genetics not dissected\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Macrophage-dependent tumor promotion by CCL8 was established genetically, showing CCL8 accelerates postpartum mammary tumorigenesis by recruiting M2 macrophages.\",\n      \"evidence\": \"Ccl8-deficient mice, tumor inoculation, and macrophage depletion rescue\",\n      \"pmids\": [\"32535027\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor on recruited macrophages not specified\", \"Context dependence on involution unexplained mechanistically\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Genetic and pharmacologic studies extended CCL8's pathogenic reach to acute GVHD mortality and to ERK1/2-driven fibroblast collagen production in fibrosis.\",\n      \"evidence\": \"Ccl8 KO with allogeneic BMT and survival; recombinant CCL8 on fibroblasts with anti-CCL8 in IgG4-related sialadenitis\",\n      \"pmids\": [\"34808257\", \"34391459\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"GVHD effector receptor and cell type not defined\", \"Fibroblast receptor mediating ERK activation not identified\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Transplant and microbial studies clarified upstream control and downstream effects, showing donor macrophage Ccl8 drives CCR8+ T-cell graft infiltration and that iron amplifies TLR4/NF-\\u03baB-driven CCL8.\",\n      \"evidence\": \"Murine kidney transplant with CCL8-CCR8 blockade and macrophage depletion; iron/F. nucleatum macrophage NF-\\u03baB analysis\",\n      \"pmids\": [\"35973731\", \"36136589\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Long-term graft outcomes not assessed\", \"Phosphatase target of iron not fully mapped\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Multiple studies converged on CCL8/CCR5 and JAK-STAT-driven CCL8 as tumor- and inflammation-promoting axes, including a CCL8/CCR5/mTORC1 metastatic loop and IFN-\\u03b3/JAK-STAT fibroblast induction.\",\n      \"evidence\": \"Lactate/M2 macrophage colorectal model with CCR5 knockdown; IFN-\\u03b3/peficitinib fibroblast RNA-seq; MSC-podocyte VCAM-1-dependent co-culture\",\n      \"pmids\": [\"38136340\", \"36672151\", \"37567910\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"mTORC1 linkage to CCR5 mechanistically thin\", \"Direct STAT binding to CCL8 promoter not shown in fibroblast study\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"In vivo gene editing established a non-immune role for CCL8 as an autocrine negative regulator of myogenic progenitor differentiation and muscle regeneration.\",\n      \"evidence\": \"AAV9 CRISPR depletion of Ccl8 in Pax7+/Myf5+/MyoD+ cells, barium chloride injury, and recombinant CCL8 rescue\",\n      \"pmids\": [\"39051762\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor mediating myogenic inhibition not identified\", \"Downstream signaling in progenitors undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"A wave of mechanistic studies defined transcriptional and chromatin regulators of CCL8 (STAT1/HSP90, IRF1/JMJD1A, CBX6/SMARCD1, USP18/SOCS1) and its roles in macrophage-mediated tumor immune evasion, cardiomyocyte inflammation, and asthma.\",\n      \"evidence\": \"Conditional KO mice, ChIP, knockdown/inhibitor studies, and CCL8-receptor-targeted DTCCL8 cytotoxin across cancer, AF, asthma, and intestinal models\",\n      \"pmids\": [\"39774471\", \"41720180\", \"41779805\", \"41219497\", \"41354823\", \"40545574\", \"41408455\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Each regulatory axis from a single lab/context\", \"Whether these converge on shared promoter elements unknown\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Senescence-focused and therapy-context studies established CCL8 from P16+ cardiac cells as a driver of cytotoxic lymphocyte recruitment impairing repair, and chemotherapy-induced CCL8 as an NK-recruitment signal.\",\n      \"evidence\": \"p16-CreER dual-recombinase genetics with Ccl8 deletion and CD8 depletion in MI; MAPK-driven CCL8 chemotaxis with NK depletion in gastric cancer\",\n      \"pmids\": [\"41766526\", \"41843172\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor on recruited cytotoxic lymphocytes not specified in cardiac model\", \"Translational relevance to human MI untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved which receptor mediates CCL8's many non-canonical, often autocrine effects (myogenesis, fibroblast ERK activation, cardiac and GVHD pathology) and how its diverse transcriptional/chromatin regulators integrate at the promoter.\",\n      \"evidence\": \"No single study in the timeline links these context-specific functions to a defined receptor or unified regulatory logic\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Receptor for muscle/fibroblast effects unknown\", \"No structural model of CCL8-receptor complexes\", \"In vivo abundance and role of the CCL8(6-75) antagonist undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [0, 7, 9, 17, 22]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [5, 14]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [0, 1, 14]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [17, 19, 21, 32]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 7, 9, 14]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [0, 3, 4, 5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"CCR1\", \"CCR2\", \"CCR5\", \"CCR8\", \"CCR3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}