{"gene":"CD83","run_date":"2026-04-28T17:28:52","timeline":{"discoveries":[{"year":2011,"finding":"The transmembrane domain of CD83 blocks IL-10-driven MARCH1-mediated ubiquitination and degradation of MHC class II and CD86 on dendritic cells, thereby stabilizing surface MHC II and CD86 expression.","method":"N-ethyl-N-nitrosourea-induced mouse mutation eliminating CD83 transmembrane region; genetic epistasis with MARCH1; functional rescue experiments","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 1-2 — in vivo genetic epistasis with defined molecular mechanism, multiple orthogonal approaches","pmids":["21220452"],"is_preprint":false},{"year":2016,"finding":"In cortical thymic epithelial cells (cTECs), CD83's transmembrane domain is necessary and sufficient for thymic CD4 T cell selection by antagonizing the E3 ubiquitin ligase March8 (not March1) to stabilize MHC II on cTECs.","method":"Viral reconstitution of CD83 gene function in thymic epithelial cells; Cd83-/- mice rescued by ablating March8; ubiquitination-resistant MHCII variant rescue","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal genetic rescue experiments, identifies specific E3 ligase substrate relationship","pmids":["27503071"],"is_preprint":false},{"year":2002,"finding":"CD83 expression by thymic epithelial and dendritic cells is required for CD4+ single-positive thymocyte development; CD83-deficient mice show a specific block in CD4+ T cell generation, and wild-type thymocytes fail to develop into CD4+ T cells in CD83-/- hosts.","method":"CD83-knockout mice; bone marrow and thymocyte transfer experiments","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 — clean KO with defined cellular phenotype replicated with adoptive transfer, published in high-impact journal","pmids":["11955430"],"is_preprint":false},{"year":2017,"finding":"Soluble CD83 (sCD83) binds to MD-2, the co-receptor of the TLR4/MD-2 complex on CD14+ monocytes, rapidly degrades IRAK-1, and induces anti-inflammatory mediators IDO, IL-10, and PGE2 in a COX-2-dependent manner, thereby suppressing T cell proliferation and IL-2 secretion.","method":"Binding assays identifying MD-2 as sCD83 partner; IRAK-1 degradation assays; pharmacological inhibition of COX-2; T cell proliferation assays","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 — receptor identification plus downstream signaling mechanism, multiple orthogonal methods","pmids":["28193829"],"is_preprint":false},{"year":2007,"finding":"HSV-1 immediate-early protein ICP0 drives proteasome-mediated degradation of CD83 in mature dendritic cells, with the RING finger E3 ubiquitin ligase activity of ICP0 required; proteasome inhibition restores CD83 surface expression.","method":"HSV-1 ICP0 deletion mutant infection; ICP0/CD83 co-transfection in 293T cells; RING finger mutant ICP0; proteasome inhibitor treatment; FACS and Western blot","journal":"Journal of virology","confidence":"High","confidence_rationale":"Tier 1-2 — multiple genetic and pharmacological approaches in same study demonstrating mechanism","pmids":["17428858"],"is_preprint":false},{"year":2014,"finding":"HSV-1 ICP0 alone is sufficient to degrade CD83 in mature dendritic cells, but this degradation is independent of ICP0's E3 ubiquitin ligase domain and independent of lysine ubiquitination, suggesting a distinct proteasomal degradation mechanism.","method":"Expression of ICP0 mutants lacking E3 ubiquitin ligase domain; E1 activating enzyme inhibitor; infection experiments in mDCs","journal":"The Journal of general virology","confidence":"Medium","confidence_rationale":"Tier 2 — single study with multiple mutant constructs, but partially contradicts prior finding on ICP0 RING domain requirement","pmids":["24643878"],"is_preprint":false},{"year":2015,"finding":"HSV-1 L particles (containing viral proteins but lacking capsid and DNA) transfer viral proteins from infected mature dendritic cells to uninfected bystander DCs, inducing CD83 downmodulation in the absence of productive infection.","method":"L particle isolation and incubation with uninfected mDCs; transwell exclusion of phagocytosis; FACS analysis of CD83","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 — mechanistic demonstration with isolated L particles and multiple controls","pmids":["26311871"],"is_preprint":false},{"year":2009,"finding":"The transmembrane RING finger E3 ubiquitin ligase GRAIL ubiquitinates CD83 on lysine residues K168 and K183 (but not K192) in its cytoplasmic domain, targeting it for 26S proteasome-mediated degradation in CD4+ T cells; GRAIL-mediated CD83 downregulation requires intact extracellular protease-associated and RING domains.","method":"Retroviral GRAIL transduction; RNA interference knockdown; site-directed mutagenesis of CD83 lysines; proteasome inhibitor assays; in vitro ubiquitination","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 1 — reconstituted ubiquitination with mutagenesis identifying specific lysines, multiple orthogonal methods","pmids":["19542455"],"is_preprint":false},{"year":2004,"finding":"HCMV infection of mature monocyte-derived dendritic cells causes shedding of CD83 from the cell surface into the supernatant as soluble CD83, and this soluble CD83 accounts for the immunosuppressive activity of infected DC supernatants on normal DC-mediated T cell stimulation.","method":"CD83 immunodepletion from HCMV-infected moDC supernatants; virion-depleted supernatant transfer; Western blot; ELISA","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 — immunodepletion demonstrates causality, single lab","pmids":["14962896"],"is_preprint":false},{"year":2001,"finding":"CD83 functions as an adhesion receptor; its soluble extracellular domain binds to monocytes and a subset of activated CD8+ T cells via a 72 kDa sialic acid-dependent counter-receptor; neuraminidase treatment abolishes binding.","method":"CD83-Ig fusion protein binding assays; immunoprecipitation of 72 kDa counter-receptor; neuraminidase treatment; CD83-transfected carcinoma cell adhesion assay","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 — Co-IP and functional binding assays identifying counter-receptor properties, single lab","pmids":["11238630"],"is_preprint":false},{"year":2001,"finding":"Soluble CD83 released from activated dendritic cells and B lymphocytes is generated by shedding of membrane CD83 (inhibition of protein synthesis does not prevent short-term sCD83 release); it is detectable in normal human serum.","method":"sCD83-specific ELISA; Western blotting; cycloheximide inhibition of protein synthesis; mCD83+ and mCD83- cell line comparison","journal":"International immunology","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological dissection of shedding mechanism, multiple methods","pmids":["11431426"],"is_preprint":false},{"year":2005,"finding":"CD83 is preformed as an intracellular protein in immature DCs, monocytes, and macrophages; its rapid surface expression upon activation is post-translationally regulated, requires glycosylation (blocked by tunicamycin), and occurs via a brefeldin A-sensitive (secretory pathway) but cycloheximide-insensitive (pre-existing protein) mechanism. Mature DCs express a 50 kDa glycoform while immature cells express a 37 kDa form.","method":"Western blotting; indirect immunofluorescence; brefeldin A, cycloheximide, and tunicamycin treatment; PNGase F digestion; flow cytometry","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1-2 — multiple pharmacological and biochemical approaches establishing post-translational regulation mechanism","pmids":["15320871"],"is_preprint":false},{"year":2006,"finding":"CD83 mRNA contains a novel cis-acting post-transcriptional regulatory element in its coding region that binds the RNA-binding protein HuR; HuR is required for cytoplasmic accumulation of CD83 mRNA via the CRM1 nuclear export pathway, and this process depends on the nucleoporin Nup214/CAN.","method":"RNA interference knockdown of HuR; transient transfection with CD83 cis-element constructs; leptomycin B (CRM1 inhibitor) treatment; dominant-negative Nup214/CAN overexpression; RNA stability assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods identifying specific RNA element, binding protein, and export pathway","pmids":["16484227"],"is_preprint":false},{"year":2006,"finding":"The HuR ligand APRIL (ANP32B) contributes to nuclear export and subsequent translation of CD83 mRNA; phosphorylation of APRIL at threonine 244 regulates its nuclear export, and APRIL knockdown reduces cytoplasmic CD83 mRNA levels.","method":"RNA interference knockdown of APRIL; identification of NLS and NES of APRIL; phosphorylation site mapping by mutagenesis; subcellular fractionation","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — RNAi plus mutagenesis in single study","pmids":["17178712"],"is_preprint":false},{"year":2005,"finding":"CD83 can be expressed as soluble forms generated by alternative splicing of CD83 mRNA; at least one splice variant is efficiently translated into protein, and recombinant soluble CD83 strongly inhibits T cell proliferation in mixed lymphocyte reactions.","method":"RT-PCR cloning and sequence analysis of CD83 transcripts from PBMCs; recombinant protein expression; MLR inhibition assays","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 — transcript characterization plus functional assay, single lab","pmids":["15905506"],"is_preprint":false},{"year":2005,"finding":"CD83 is a disulfide-linked dimer; the fifth cysteine residue at amino acid position 129 in the extracellular Ig domain mediates dimerization via an intermolecular disulfide bond, and a C129S mutant monomeric form retains inhibitory activity on DC maturation and allogeneic T cell stimulation in MLR.","method":"Recombinant mutagenesis (C129S substitution); non-reducing SDS-PAGE; MLR assays; DC maturation assays","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 1-2 — mutagenesis combined with biochemical and functional assays, single study","pmids":["15721284"],"is_preprint":false},{"year":2002,"finding":"The CD83 promoter contains four SP1 binding sites and one NF-κB element; NF-κB factors specifically bind the NF-κB element (confirmed by EMSA), and promoter activity is inducible by TNF-α in a manner strictly dependent on the intact NF-κB element.","method":"Promoter deletion constructs; luciferase reporter assays; electrophoretic mobility shift assays (EMSA); TNF-α stimulation","journal":"Immunobiology","confidence":"Medium","confidence_rationale":"Tier 1-2 — EMSA and functional promoter mutagenesis, single lab","pmids":["12182451"],"is_preprint":false},{"year":2003,"finding":"EBV latent membrane protein 1 (LMP1) induces CD83 expression in B cells via NF-κB activation; LMP1 mutant studies and luciferase reporter assays with the CD83 promoter demonstrated NF-κB dependence; signaling through CD40, TNF-R1, or TNF-R2 intracellular domains fused to LMP1 transmembrane domain similarly activates the CD83 promoter.","method":"Inducible LMP1 expression system (NGFR-LMP1 fusion); luciferase reporter assays with CD83 promoter and LMP1 mutants; EBNA2-inducible LCL system","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 — multiple genetic constructs establishing NF-κB as the upstream transcriptional activator of CD83 in B cells","pmids":["12857898"],"is_preprint":false},{"year":2011,"finding":"CD83 on monocytes, when stimulated by CD83 (membrane CD83 on DCs or T cells), induces COX-2-dependent PGE2 production via NF-κB activation, and this PGE2 mediates T cell suppression (inhibiting IL-2 and IFN-γ); COX-2-selective inhibitor NS-398 fully prevented CD83-triggered T cell inhibition.","method":"COX-2 inhibitor (NS-398) treatment; NF-κB pathway analysis; ELISA for PGE2 and cytokines; T cell proliferation assays with monocyte co-cultures","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological epistasis with multiple readouts, single lab","pmids":["22065790"],"is_preprint":false},{"year":2014,"finding":"CD83 homotypic interactions between dendritic cells (via cell-cell contact) inhibit pro-inflammatory responses by suppressing p38α phosphorylation in the MAPK pathway; CD83 cytoplasmic truncation or knockdown abolishes this homotypic inhibitory signaling.","method":"DC conditional knockout of CD83; CD83 overexpression; CD83 knockdown; cytoplasmic truncation mutants; p38α phosphorylation assays; in vitro and in vivo colitis models","journal":"Mucosal immunology","confidence":"Medium","confidence_rationale":"Tier 2 — domain-specific mutants establishing signaling mechanism, multiple methods, single lab","pmids":["25204675"],"is_preprint":false},{"year":2007,"finding":"CD83 knockdown by siRNA in human monocyte-derived DCs significantly reduces DC-mediated T cell proliferation and alters cytokine expression during T cell priming, demonstrating CD83's role as an enhancer of T cell stimulatory capacity.","method":"siRNA electroporation into immature DCs; flow cytometry; allogeneic T cell proliferation assays; cytokine measurements","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 — specific RNAi knockdown with functional readout, single lab","pmids":["17442926"],"is_preprint":false},{"year":2008,"finding":"Retroviral transduction of CD83 into naive CD4+CD25- T cells induces a regulatory phenotype including Foxp3 expression; CD83+Foxp3+ T cells suppress contact hypersensitivity and prevent EAE in vivo, reducing IFN-γ and IL-17 while increasing IL-10.","method":"Retroviral transduction of CD83 into T cells; adoptive transfer into EAE and contact hypersensitivity models; cytokine measurement","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 — gain-of-function with in vivo functional readout, single lab","pmids":["18424708"],"is_preprint":false},{"year":2018,"finding":"Treg-intrinsic CD83 expression is essential for Treg differentiation upon activation; conditional Treg-specific CD83 knockout mice develop a pro-inflammatory phenotype with loss of Treg-specific differentiation markers and induction of an inflammatory profile.","method":"Treg-specific conditional CD83 knockout mice; scRNA-seq; flow cytometry; autoimmunity models","journal":"JCI insight","confidence":"Medium","confidence_rationale":"Tier 2 — conditional KO with defined cellular phenotype, single lab","pmids":["29875316"],"is_preprint":false},{"year":2019,"finding":"DC-specific conditional CD83 knockout DCs produce drastically increased IL-2, higher CD25 and OX40L expression, causing superior T cell responses and compromised Treg suppressive functions; CD83-deficient DCs express increased IL-12 after bacterial encounter, leading to accelerated immune responses and exacerbated autoimmunity in EAE.","method":"DC-specific CD83 conditional KO (CD83ΔDC) mice; bacterial infection models (Salmonella, Listeria); EAE model; flow cytometry; cytokine measurements","journal":"JCI insight","confidence":"Medium","confidence_rationale":"Tier 2 — cell-type-specific KO with multiple functional readouts, single lab","pmids":["31527313"],"is_preprint":false},{"year":2016,"finding":"B cell-specific CD83 knockout B cells show defective upregulation of MHC class II and CD86 after stimulation, impaired proliferation, a shift toward increased dark zone GC B cells, and enhanced IgE responses; CD83-deficient B cells have a competitive disadvantage in GC responses.","method":"B cell-specific CD83 conditional KO mice; mixed BM chimeras; GC analysis by flow cytometry; immunization experiments; Borrelia burgdorferi infection model","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 — cell-type-specific KO with multiple functional readouts, single lab","pmids":["26983787"],"is_preprint":false},{"year":2011,"finding":"Activated T cells induce CD83 expression on B cells through CD40 engagement (not TCR/MHC binding or soluble factors), as demonstrated by anti-CD40L antibody blockade and transwell experiments.","method":"T cell receptor transgenic mice; transwell co-culture; anti-CD40L antibody blockade; in vivo peptide injection; flow cytometry","journal":"Immunology letters","confidence":"Medium","confidence_rationale":"Tier 2 — receptor blockade and contact-dependency experiments establishing CD40-CD40L as the induction signal","pmids":["21277328"],"is_preprint":false},{"year":2004,"finding":"Soluble CD83 treatment of mature DCs completely alters their cytoskeleton (assessed by phalloidin, tubulin, and fascin staining), causing cell rounding and loss of veils, and completely inhibits DC-T cell cluster formation.","method":"Phalloidin, tubulin, and fascin immunofluorescence staining; DC-T cell clustering assays; recombinant sCD83 treatment","journal":"Immunobiology","confidence":"Low","confidence_rationale":"Tier 3 — single lab, descriptive morphological readout without defined molecular mechanism","pmids":["15481147"],"is_preprint":false},{"year":2023,"finding":"CD83 expression in murine microglia is associated with pro-resolving functions; conditional deletion of CD83 in microglia results in an over-activated state during EAE neuroinflammation, with increased recruitment of pathogenic immune cells to the CNS and exacerbated disease.","method":"Conditional microglia-specific CD83 KO mice; EAE model; single-cell RNA-sequencing; flow cytometry of CNS infiltrates","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 — cell-type-specific KO with scRNA-seq and functional in vivo readout","pmids":["37528070"],"is_preprint":false},{"year":2014,"finding":"Membrane CD83 on mature DCs enhances intracellular calcium release in T lymphocytes upon DC-T cell contact; CD83 knockdown or antibody blockade reduces calcium signal amplitude and T cell proliferation.","method":"siRNA knockdown of CD83; anti-CD83 antibody blockade; Fluo-4-AM calcium indicator; flow cytometry and confocal microscopy; CFSE proliferation assay; calcium chelation","journal":"Journal of leukocyte biology","confidence":"Medium","confidence_rationale":"Tier 2 — two independent perturbation approaches (RNAi and antibody) with calcium signaling readout","pmids":["24436459"],"is_preprint":false},{"year":2019,"finding":"Soluble CD83 enhances resolution of antigen-induced arthritis by reducing IL-17A, IFN-γ, IL-6, TNF-α, and RANKL in joints; this mechanism is IDO-dependent (abrogated by 1-methyltryptophan) and also involves TGF-β (blocked by anti-TGF-β antibodies), with induction of regulatory T cells.","method":"Mouse AIA model; IDO inhibitor (1-methyltryptophan); anti-TGF-β antibody blockade; flow cytometry of Tregs; cytokine measurement; histological analysis of bone destruction","journal":"Frontiers in immunology","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological epistasis with multiple pathway inhibitors and functional readouts, single lab","pmids":["31001257"],"is_preprint":false}],"current_model":"CD83 is a transmembrane immunoglobulin superfamily glycoprotein expressed on mature dendritic cells, activated lymphocytes, and regulatory T cells that functions as an immune checkpoint: its transmembrane domain stabilizes surface MHC II and CD86 by blocking ubiquitin E3 ligases MARCH1 (in DCs) and March8 (in cortical thymic epithelial cells), thereby enabling CD4+ T cell selection; its expression is post-translationally regulated by glycosylation and at the mRNA level through a HuR/CRM1-dependent nuclear export pathway; its promoter is activated by NF-κB (induced by TNF-α and viral LMP1); HSV-1 ICP0 drives proteasomal degradation of CD83 as a viral immune escape mechanism; GRAIL ubiquitinates CD83 at K168/K183 for proteasomal degradation in anergic CD4+ T cells; membrane CD83 enhances T cell activation by boosting intracellular calcium release; soluble CD83 (generated by alternative splicing and shedding) exerts immunosuppressive effects by binding MD-2 within the TLR4/MD-2 complex on monocytes to induce IDO, IL-10, and PGE2 production, and by engaging CD40 to regulate B cell antibody responses; CD83 expression in DCs, Tregs, and microglia restrains excessive inflammation and promotes immune tolerance."},"narrative":{"teleology":[{"year":2001,"claim":"Establishing that CD83 has a ligand-binding function: the extracellular domain was shown to engage a 72 kDa sialic acid-dependent counter-receptor on monocytes and activated CD8+ T cells, and that membrane CD83 is shed to produce a soluble form detectable in serum, framing CD83 as both a membrane receptor and a released immunomodulator.","evidence":"CD83-Ig fusion protein binding assays with neuraminidase treatment; sCD83-specific ELISA with cycloheximide blockade showing shedding mechanism","pmids":["11238630","11431426"],"confidence":"Medium","gaps":["Identity of the 72 kDa counter-receptor was not determined","Protease responsible for shedding not identified","Physiological relevance of serum sCD83 levels not established"]},{"year":2002,"claim":"Demonstrating that CD83 is non-redundantly required for CD4+ T cell development: CD83-knockout mice showed a specific block in CD4+ single-positive thymocyte generation, and the defect mapped to thymic stromal cells rather than thymocytes, establishing CD83 as essential for thymic positive selection.","evidence":"CD83-knockout mice with bone marrow and thymocyte adoptive transfer experiments","pmids":["11955430"],"confidence":"High","gaps":["Molecular mechanism by which CD83 promotes CD4 selection was unknown","Whether CD83 acted on MHC II stability or via a signaling pathway was unresolved"]},{"year":2002,"claim":"Defining the transcriptional regulation of CD83: the promoter was shown to be NF-κB-dependent and TNF-α-inducible, and EBV LMP1 was later shown to activate CD83 transcription through the same NF-κB element, linking viral latency to CD83 upregulation in B cells.","evidence":"Promoter deletion/reporter assays with EMSA; LMP1 mutant and chimeric receptor reporter assays","pmids":["12182451","12857898"],"confidence":"Medium","gaps":["Other transcription factors contributing to cell-type-specific CD83 expression were not characterized","Epigenetic regulation not examined"]},{"year":2005,"claim":"Resolving how CD83 surface expression is so rapidly induced: preformed CD83 protein exists intracellularly in immature DCs and is trafficked to the surface upon activation through a glycosylation-dependent, secretory-pathway mechanism that does not require new protein synthesis, revealing post-translational rather than transcriptional control as the primary switch.","evidence":"Brefeldin A, cycloheximide, and tunicamycin treatment of DCs; PNGase F digestion; flow cytometry and Western blot","pmids":["15320871"],"confidence":"High","gaps":["Glycosyltransferases responsible for the 37→50 kDa modification not identified","Signal triggering ER-to-surface trafficking not defined"]},{"year":2005,"claim":"Characterizing alternative forms of soluble CD83: alternative splicing was identified as a second source (beyond shedding) of soluble CD83, and the soluble protein was shown to potently inhibit T cell proliferation, while structural analysis revealed CD83 forms a disulfide-linked dimer via C129, though dimerization is dispensable for immunosuppressive function.","evidence":"RT-PCR cloning of splice variants; recombinant sCD83 in MLR; C129S mutagenesis with non-reducing SDS-PAGE","pmids":["15905506","15721284"],"confidence":"Medium","gaps":["Relative contributions of splicing versus shedding to sCD83 pools in vivo unknown","Whether dimerization affects receptor binding affinity not tested"]},{"year":2006,"claim":"Uncovering a post-transcriptional regulatory circuit: CD83 mRNA contains a cis-acting element bound by HuR, which mediates CRM1/Nup214-dependent nuclear export; the HuR co-factor APRIL/ANP32B further promotes this export in a phosphorylation-dependent manner, establishing mRNA export as a rate-limiting step in CD83 expression.","evidence":"HuR and APRIL RNAi; leptomycin B treatment; dominant-negative Nup214; phosphorylation site mutagenesis","pmids":["16484227","17178712"],"confidence":"High","gaps":["Whether this mRNA export mechanism operates in all CD83-expressing cell types not tested","Kinase phosphorylating APRIL T244 not identified"]},{"year":2007,"claim":"Identifying viral immune evasion targeting CD83: HSV-1 ICP0 was shown to drive proteasomal degradation of CD83 in mature DCs, initially attributed to ICP0's RING finger E3 ligase activity, though a subsequent study found degradation to be independent of this domain, leaving the precise mechanism debated.","evidence":"HSV-1 ICP0 deletion/RING mutants; proteasome inhibitor rescue; FACS and Western blot in mDCs and 293T cells","pmids":["17428858","24643878"],"confidence":"Medium","gaps":["Whether ICP0 directly ubiquitinates CD83 or recruits another E3 ligase is unresolved","The contradictory findings on RING domain requirement have not been reconciled"]},{"year":2009,"claim":"Defining a T cell-intrinsic ubiquitin-dependent degradation pathway for CD83: GRAIL was identified as the E3 ligase ubiquitinating CD83 at K168 and K183 for proteasomal degradation in CD4+ T cells, providing a molecular mechanism for CD83 downregulation during T cell anergy.","evidence":"Retroviral GRAIL transduction; site-directed mutagenesis of CD83 lysines; in vitro ubiquitination assay; proteasome inhibitor rescue","pmids":["19542455"],"confidence":"High","gaps":["Whether GRAIL targets CD83 in vivo during anergy induction not demonstrated","Signals coupling anergy to GRAIL-CD83 interaction not defined"]},{"year":2011,"claim":"Solving the molecular mechanism of CD83 in MHC II stabilization: the transmembrane domain of CD83 was shown to block MARCH1-mediated ubiquitination and degradation of MHC II and CD86 on DCs, establishing CD83 as a competitive inhibitor of MARCH E3 ligases rather than a conventional signaling receptor.","evidence":"ENU-induced CD83 transmembrane mutant mice; genetic epistasis with MARCH1 knockout; functional rescue","pmids":["21220452"],"confidence":"High","gaps":["Whether CD83 TMD directly binds MARCH1 TMD or acts indirectly not determined","Stoichiometry of CD83–MARCH1 interaction unknown"]},{"year":2011,"claim":"Identifying the signal inducing CD83 on B cells and a downstream immunosuppressive effector: CD40 engagement by T cells was shown to drive CD83 upregulation on B cells, and membrane CD83 engagement on monocytes triggers COX-2-dependent PGE2 production via NF-κB, mediating T cell suppression.","evidence":"Anti-CD40L blockade and transwell experiments; COX-2 inhibitor NS-398 treatment with cytokine and proliferation assays","pmids":["21277328","22065790"],"confidence":"Medium","gaps":["Direct receptor for membrane CD83 on monocytes not identified at this stage","Whether PGE2 pathway operates in vivo not shown"]},{"year":2014,"claim":"Demonstrating that membrane CD83 actively promotes T cell activation through calcium signaling and that homotypic DC–DC CD83 interactions suppress inflammation via p38α: these findings revealed CD83 has dual context-dependent functions—costimulatory in DC–T cell contact and inhibitory in DC–DC contact.","evidence":"CD83 siRNA and anti-CD83 antibody with Fluo-4-AM calcium imaging; CD83 cytoplasmic truncation mutants with p38α phosphorylation assays in colitis models","pmids":["24436459","25204675"],"confidence":"Medium","gaps":["T cell receptor for membrane CD83 not identified","Whether cytoplasmic domain signals directly or via adaptor proteins unknown"]},{"year":2016,"claim":"Extending the MARCH-antagonism model to thymic selection: in cortical thymic epithelial cells, CD83 TMD antagonizes March8 (not March1) to stabilize MHC II, directly explaining the CD4+ T cell selection defect in CD83-knockout mice identified 14 years earlier.","evidence":"Cd83−/− cTEC reconstitution; March8 ablation rescue; ubiquitination-resistant MHC II variant rescue in CD83-deficient thymus","pmids":["27503071"],"confidence":"High","gaps":["Whether CD83 TMD binds March8 directly or competes for substrate access not resolved","Structural basis of E3 ligase selectivity (March1 in DCs vs March8 in cTECs) unknown"]},{"year":2016,"claim":"Establishing a B cell-intrinsic role for CD83: B cell-specific CD83 deletion revealed impaired MHC II and CD86 upregulation, defective germinal center responses, and dysregulated IgE production, extending the MARCH-antagonism paradigm to the B cell lineage.","evidence":"B cell-specific CD83 conditional KO mice; mixed bone marrow chimeras; immunization and infection models","pmids":["26983787"],"confidence":"Medium","gaps":["Which MARCH family member CD83 antagonizes in B cells not determined","Whether GC phenotype is solely due to MHC II instability or additional pathways unclear"]},{"year":2017,"claim":"Identifying the receptor for soluble CD83: sCD83 was shown to bind MD-2 within the TLR4/MD-2 complex on monocytes, triggering IRAK-1 degradation and inducing IDO, IL-10, and PGE2, providing a unified molecular explanation for the immunosuppressive activity of sCD83.","evidence":"Direct binding assays identifying MD-2; IRAK-1 degradation kinetics; COX-2 inhibition; T cell proliferation assays","pmids":["28193829"],"confidence":"High","gaps":["Whether sCD83 competes with LPS for MD-2 binding not addressed","Crystal structure of sCD83–MD-2 complex not available"]},{"year":2018,"claim":"Demonstrating Treg-intrinsic requirement for CD83: conditional Treg-specific CD83 deletion caused loss of Treg differentiation markers and a pro-inflammatory phenotype, establishing that CD83 is not merely a Treg marker but functions cell-autonomously in Treg identity and suppressive capacity.","evidence":"Treg-specific conditional CD83 KO mice; scRNA-seq; autoimmunity phenotyping","pmids":["29875316"],"confidence":"Medium","gaps":["Whether Treg CD83 acts via MARCH antagonism or an independent mechanism not determined","Direct target of CD83 signaling within Tregs unknown"]},{"year":2019,"claim":"Extending CD83's immune-regulatory role to DCs and demonstrating sCD83 therapeutic mechanism: DC-specific CD83 deletion caused hyperactivated DCs with excess IL-2 and IL-12 production leading to exacerbated autoimmunity, while sCD83 resolved arthritis via IDO- and TGF-β-dependent Treg induction.","evidence":"DC-specific CD83 conditional KO in EAE and infection models; sCD83 treatment in antigen-induced arthritis with IDO inhibitor and anti-TGF-β blockade","pmids":["31527313","31001257"],"confidence":"Medium","gaps":["Whether DC CD83 restraint operates through MARCH1 antagonism or additional pathways not fully resolved","Pharmacokinetics and in vivo receptor engagement of sCD83 not characterized"]},{"year":2023,"claim":"Extending CD83 immune-regulatory function to the CNS: microglia-specific CD83 deletion led to over-activated microglia and exacerbated neuroinflammation in EAE, demonstrating that CD83's tolerance-promoting role extends beyond classical adaptive immune cells to CNS-resident innate immune cells.","evidence":"Conditional microglia-specific CD83 KO mice; EAE model; single-cell RNA-seq; CNS infiltrate analysis","pmids":["37528070"],"confidence":"Medium","gaps":["Whether microglial CD83 antagonizes a MARCH ligase or acts via a distinct mechanism unknown","Microglial CD83 ligand or signaling partners not identified"]},{"year":null,"claim":"Key unresolved questions include the structural basis of CD83 transmembrane domain interaction with MARCH E3 ligases, the identity of the membrane CD83 counter-receptor on T cells, whether MARCH antagonism fully explains CD83 function in Tregs and microglia, and the in vivo therapeutic potential of sCD83 via the MD-2 axis.","evidence":"Open questions from the accumulated literature","pmids":[],"confidence":"Medium","gaps":["No structural model of CD83 TMD–MARCH interaction exists","T cell counter-receptor for membrane CD83 remains unidentified","Cell-type-specific mechanisms beyond MARCH antagonism are undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,24]},{"term_id":"GO:0098631","term_label":"cell adhesion mediator activity","supporting_discovery_ids":[9]},{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[3,18]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,1,11,28]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[3,10,14]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[11]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0,1,2,3,22,23,27]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,1,7]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,18,19]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[1,2]}],"complexes":[],"partners":["MARCH1","MARCH8","LY96","RNF128","ELAVL1","CD40"],"other_free_text":[]},"mechanistic_narrative":"CD83 is an immunoglobulin superfamily glycoprotein that functions as a central regulator of antigen presentation and immune tolerance across dendritic cells, B cells, regulatory T cells, and microglia. Its transmembrane domain stabilizes surface MHC class II and CD86 by antagonizing MARCH1-mediated ubiquitination in dendritic cells and March8-mediated ubiquitination in cortical thymic epithelial cells, a mechanism essential for CD4+ T cell thymic selection and peripheral T cell priming [PMID:21220452, PMID:27503071, PMID:11955430]. Soluble CD83, generated by both alternative splicing and proteolytic shedding, exerts immunosuppressive effects by binding MD-2 in the TLR4/MD-2 complex on monocytes to induce IDO, IL-10, and PGE2 production, and CD83 expression in Tregs, DCs, and microglia restrains inflammatory responses, as conditional deletion in each lineage results in exacerbated autoimmunity [PMID:28193829, PMID:29875316, PMID:31527313, PMID:37528070]. CD83 protein levels are regulated post-translationally by glycosylation-dependent trafficking from preformed intracellular stores, by GRAIL-mediated ubiquitination at K168/K183 in anergic T cells, and by HSV-1 ICP0-directed proteasomal degradation as a viral immune evasion strategy [PMID:15320871, PMID:19542455, PMID:17428858]."},"prefetch_data":{"uniprot":{"accession":"Q01151","full_name":"CD83 antigen","aliases":["B-cell activation protein","Cell surface protein HB15"],"length_aa":205,"mass_kda":23.0,"function":"Transmembrane glycoprotein predominantly found on the surface of many immune cells including dendritic cells or lymphocytes that plays various roles in immune response regulation. Plays an essential role in CD4(+) T-selection, differentiation and stability by regulating the activity of the major E3 ubiquitin ligase responsible for controlling MHCII trafficking MARCHF8. Also inhibits MARCHF1 association with MHCII or CD86 to prevent their ubiquitination and subsequent degradation (PubMed:21220452). In addition, acts as an important modulator of protective responses against acute infections (By similarity)","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/Q01151/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CD83","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CD83","total_profiled":1310},"omim":[{"mim_id":"618806","title":"T-CELL LYMPHOPENIA, INFANTILE, WITH OR WITHOUT NAIL DYSTROPHY, AUTOSOMAL DOMINANT; TLIND","url":"https://www.omim.org/entry/618806"},{"mim_id":"614372","title":"MANNOSE-BINDING LECTIN DEFICIENCY; MBLD","url":"https://www.omim.org/entry/614372"},{"mim_id":"609888","title":"LEPROSY, SUSCEPTIBILITY TO, 1; LPRS1","url":"https://www.omim.org/entry/609888"},{"mim_id":"604534","title":"CD83 ANTIGEN; CD83","url":"https://www.omim.org/entry/604534"},{"mim_id":"604472","title":"TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY, MEMBER 13; TNFSF13","url":"https://www.omim.org/entry/604472"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Plasma membrane","reliability":"Approved"},{"location":"Nucleoli","reliability":"Additional"},{"location":"Golgi apparatus","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"bone marrow","ntpm":197.9}],"url":"https://www.proteinatlas.org/search/CD83"},"hgnc":{"alias_symbol":["HB15","BL11"],"prev_symbol":[]},"alphafold":{"accession":"Q01151","domains":[{"cath_id":"2.60.40.10","chopping":"17-128","consensus_level":"high","plddt":78.2339,"start":17,"end":128},{"cath_id":"1.20.5","chopping":"134-166","consensus_level":"medium","plddt":85.5897,"start":134,"end":166}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q01151","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q01151-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q01151-F1-predicted_aligned_error_v6.png","plddt_mean":72.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CD83","jax_strain_url":"https://www.jax.org/strain/search?query=CD83"},"sequence":{"accession":"Q01151","fasta_url":"https://rest.uniprot.org/uniprotkb/Q01151.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q01151/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q01151"}},"corpus_meta":[{"pmid":"7706722","id":"PMC_7706722","title":"Human blood dendritic cells selectively express CD83, a member of the immunoglobulin superfamily.","date":"1995","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/7706722","citation_count":640,"is_preprint":false},{"pmid":"20484028","id":"PMC_20484028","title":"Immature immunosuppressive CD14+HLA-DR-/low cells in melanoma patients are Stat3hi and overexpress CD80, CD83, and DC-sign.","date":"2010","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/20484028","citation_count":330,"is_preprint":false},{"pmid":"9743339","id":"PMC_9743339","title":"Prostaglandin E2 induces the final maturation of IL-12-deficient CD1a+CD83+ dendritic cells: the levels of IL-12 are determined during the final dendritic cell maturation and are resistant to further modulation.","date":"1998","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/9743339","citation_count":245,"is_preprint":false},{"pmid":"16203865","id":"PMC_16203865","title":"IL-18-induced CD83+CCR7+ NK helper cells.","date":"2005","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/16203865","citation_count":235,"is_preprint":false},{"pmid":"12072358","id":"PMC_12072358","title":"CD83 on dendritic cells: more than just a marker for maturation.","date":"2002","source":"Trends in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/12072358","citation_count":191,"is_preprint":false},{"pmid":"21220452","id":"PMC_21220452","title":"CD83 increases MHC II and CD86 on dendritic cells by opposing IL-10-driven MARCH1-mediated ubiquitination and degradation.","date":"2011","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/21220452","citation_count":187,"is_preprint":false},{"pmid":"11955430","id":"PMC_11955430","title":"CD83 expression influences CD4+ T cell development in the thymus.","date":"2002","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/11955430","citation_count":173,"is_preprint":false},{"pmid":"17301951","id":"PMC_17301951","title":"CD83 expression on dendritic cells and T cells: correlation with effective immune responses.","date":"2007","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/17301951","citation_count":168,"is_preprint":false},{"pmid":"10880386","id":"PMC_10880386","title":"Human decidua contains potent immunostimulatory CD83(+) dendritic cells.","date":"2000","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/10880386","citation_count":144,"is_preprint":false},{"pmid":"15320871","id":"PMC_15320871","title":"CD83 is preformed inside monocytes, macrophages and dendritic cells, but it is only stably expressed on activated dendritic cells.","date":"2005","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/15320871","citation_count":141,"is_preprint":false},{"pmid":"16239433","id":"PMC_16239433","title":"Engagement of CD83 ligand induces prolonged expansion of CD8+ T cells and preferential enrichment for antigen specificity.","date":"2005","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/16239433","citation_count":139,"is_preprint":false},{"pmid":"31231400","id":"PMC_31231400","title":"CD83: Activation Marker for Antigen Presenting Cells and Its Therapeutic Potential.","date":"2019","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/31231400","citation_count":138,"is_preprint":false},{"pmid":"14962896","id":"PMC_14962896","title":"Infection of mature monocyte-derived dendritic cells with human cytomegalovirus inhibits stimulation of T-cell proliferation via the release of soluble CD83.","date":"2004","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/14962896","citation_count":122,"is_preprint":false},{"pmid":"17334966","id":"PMC_17334966","title":"CD83: an update on functions and prospects of the maturation marker of dendritic cells.","date":"2007","source":"Archives of dermatological research","url":"https://pubmed.ncbi.nlm.nih.gov/17334966","citation_count":120,"is_preprint":false},{"pmid":"18292234","id":"PMC_18292234","title":"Rheumatoid arthritis synovium contains two subsets of CD83-DC-LAMP- dendritic cells with distinct cytokine profiles.","date":"2008","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/18292234","citation_count":120,"is_preprint":false},{"pmid":"15289503","id":"PMC_15289503","title":"Prevention and treatment of experimental autoimmune encephalomyelitis by soluble CD83.","date":"2004","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/15289503","citation_count":116,"is_preprint":false},{"pmid":"11090084","id":"PMC_11090084","title":"Expression of CCR6 and CD83 by cytokine-activated human neutrophils.","date":"2000","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/11090084","citation_count":114,"is_preprint":false},{"pmid":"11431426","id":"PMC_11431426","title":"A soluble form of CD83 is released from activated dendritic cells and B lymphocytes, and is detectable in normal human sera.","date":"2001","source":"International immunology","url":"https://pubmed.ncbi.nlm.nih.gov/11431426","citation_count":113,"is_preprint":false},{"pmid":"32362900","id":"PMC_32362900","title":"The CD83 Molecule - An Important Immune Checkpoint.","date":"2020","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/32362900","citation_count":109,"is_preprint":false},{"pmid":"10360962","id":"PMC_10360962","title":"HLA-G in the human thymus: a subpopulation of medullary epithelial but not CD83(+) dendritic cells expresses HLA-G as a membrane-bound and soluble protein.","date":"1999","source":"International immunology","url":"https://pubmed.ncbi.nlm.nih.gov/10360962","citation_count":108,"is_preprint":false},{"pmid":"18329338","id":"PMC_18329338","title":"CD83 regulates lymphocyte maturation, activation and homeostasis.","date":"2008","source":"Trends in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/18329338","citation_count":98,"is_preprint":false},{"pmid":"17442926","id":"PMC_17442926","title":"CD83 knockdown in monocyte-derived dendritic cells by small interfering RNA leads to a diminished T cell stimulation.","date":"2007","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/17442926","citation_count":98,"is_preprint":false},{"pmid":"11884422","id":"PMC_11884422","title":"Cutting edge: CD83 regulates the development of cellular immunity.","date":"2002","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/11884422","citation_count":90,"is_preprint":false},{"pmid":"15699136","id":"PMC_15699136","title":"TGF-beta and vitamin D3 utilize distinct pathways to suppress IL-12 production and modulate rapid differentiation of human monocytes into CD83+ dendritic cells.","date":"2005","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/15699136","citation_count":84,"is_preprint":false},{"pmid":"11238630","id":"PMC_11238630","title":"CD83 is an I-type lectin adhesion receptor that binds monocytes and a subset of activated CD8+ T cells [corrected].","date":"2001","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/11238630","citation_count":83,"is_preprint":false},{"pmid":"26983787","id":"PMC_26983787","title":"CD83 Modulates B Cell Activation and Germinal Center Responses.","date":"2016","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/26983787","citation_count":79,"is_preprint":false},{"pmid":"11511977","id":"PMC_11511977","title":"Transdifferentiation of polymorphonuclear neutrophils: acquisition of CD83 and other functional characteristics of dendritic cells.","date":"2001","source":"Journal of molecular medicine (Berlin, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/11511977","citation_count":73,"is_preprint":false},{"pmid":"12403928","id":"PMC_12403928","title":"Role of CD83 in the immunomodulation of dendritic cells.","date":"2002","source":"International archives of allergy and immunology","url":"https://pubmed.ncbi.nlm.nih.gov/12403928","citation_count":69,"is_preprint":false},{"pmid":"17428858","id":"PMC_17428858","title":"Herpes simplex virus type 1 induces CD83 degradation in mature dendritic cells with immediate-early kinetics via the cellular proteasome.","date":"2007","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/17428858","citation_count":68,"is_preprint":false},{"pmid":"16484227","id":"PMC_16484227","title":"Expression of CD83 is regulated by HuR via a novel cis-active coding region RNA element.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16484227","citation_count":66,"is_preprint":false},{"pmid":"27503071","id":"PMC_27503071","title":"Thymic CD4 T cell selection requires attenuation of March8-mediated MHCII turnover in cortical epithelial cells through CD83.","date":"2016","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/27503071","citation_count":66,"is_preprint":false},{"pmid":"18424708","id":"PMC_18424708","title":"CD83 expression in CD4+ T cells modulates inflammation and autoimmunity.","date":"2008","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/18424708","citation_count":64,"is_preprint":false},{"pmid":"15383588","id":"PMC_15383588","title":"Homologs of CD83 from elasmobranch and teleost fish.","date":"2004","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/15383588","citation_count":64,"is_preprint":false},{"pmid":"14972446","id":"PMC_14972446","title":"CD83(+)dendritic cells in the decidua of women with recurrent miscarriage and normal pregnancy.","date":"2004","source":"Placenta","url":"https://pubmed.ncbi.nlm.nih.gov/14972446","citation_count":64,"is_preprint":false},{"pmid":"19171763","id":"PMC_19171763","title":"Antibody to the dendritic cell surface activation antigen CD83 prevents acute graft-versus-host disease.","date":"2009","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/19171763","citation_count":61,"is_preprint":false},{"pmid":"11536161","id":"PMC_11536161","title":"Human monocyte-derived and CD83(+) blood dendritic cells enhance NK cell-mediated cytotoxicity.","date":"2001","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/11536161","citation_count":60,"is_preprint":false},{"pmid":"28193829","id":"PMC_28193829","title":"Soluble CD83 Inhibits T Cell Activation by Binding to the TLR4/MD-2 Complex on CD14+ Monocytes.","date":"2017","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/28193829","citation_count":56,"is_preprint":false},{"pmid":"14687618","id":"PMC_14687618","title":"The soluble form of CD83 is present at elevated levels in a number of hematological malignancies.","date":"2004","source":"Leukemia research","url":"https://pubmed.ncbi.nlm.nih.gov/14687618","citation_count":56,"is_preprint":false},{"pmid":"20861805","id":"PMC_20861805","title":"Immunosuppression involving soluble CD83 induces tolerogenic dendritic cells that prevent cardiac allograft rejection.","date":"2010","source":"Transplantation","url":"https://pubmed.ncbi.nlm.nih.gov/20861805","citation_count":54,"is_preprint":false},{"pmid":"17178712","id":"PMC_17178712","title":"Analysis of nucleocytoplasmic trafficking of the HuR ligand APRIL and its influence on CD83 expression.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17178712","citation_count":53,"is_preprint":false},{"pmid":"11588047","id":"PMC_11588047","title":"Calcium signaling inhibits interleukin-12 production and activates CD83(+) dendritic cells that induce Th2 cell development.","date":"2001","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/11588047","citation_count":52,"is_preprint":false},{"pmid":"15905506","id":"PMC_15905506","title":"Alternative splicing generates putative soluble CD83 proteins that inhibit T cell proliferation.","date":"2005","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/15905506","citation_count":51,"is_preprint":false},{"pmid":"29875316","id":"PMC_29875316","title":"CD83 expression is essential for Treg cell differentiation and stability.","date":"2018","source":"JCI insight","url":"https://pubmed.ncbi.nlm.nih.gov/29875316","citation_count":50,"is_preprint":false},{"pmid":"17266176","id":"PMC_17266176","title":"CD83 is a regulator of murine B cell function in vivo.","date":"2007","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/17266176","citation_count":49,"is_preprint":false},{"pmid":"18001846","id":"PMC_18001846","title":"Dendritic cell CD83: a therapeutic target or innocent bystander?","date":"2007","source":"Immunology letters","url":"https://pubmed.ncbi.nlm.nih.gov/18001846","citation_count":47,"is_preprint":false},{"pmid":"9091299","id":"PMC_9091299","title":"In vitro generation of CD83+ human blood dendritic cells for active tumor immunotherapy.","date":"1997","source":"Experimental hematology","url":"https://pubmed.ncbi.nlm.nih.gov/9091299","citation_count":46,"is_preprint":false},{"pmid":"17291220","id":"PMC_17291220","title":"A limited course of soluble CD83 delays acute cellular rejection of MHC-mismatched mouse skin allografts.","date":"2007","source":"Transplant international : official journal of the European Society for Organ Transplantation","url":"https://pubmed.ncbi.nlm.nih.gov/17291220","citation_count":45,"is_preprint":false},{"pmid":"16704455","id":"PMC_16704455","title":"Melanogenesis and evidence for melanosome transport to the plasma membrane in a CD83 teleost leukocyte cell line.","date":"2006","source":"Pigment cell research","url":"https://pubmed.ncbi.nlm.nih.gov/16704455","citation_count":45,"is_preprint":false},{"pmid":"17710154","id":"PMC_17710154","title":"CD83 modulates B cell function in vitro: increased IL-10 and reduced Ig secretion by CD83Tg B cells.","date":"2007","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/17710154","citation_count":43,"is_preprint":false},{"pmid":"32437331","id":"PMC_32437331","title":"Human CD83-targeted chimeric antigen receptor T cells prevent and treat graft-versus-host disease.","date":"2020","source":"The Journal of clinical investigation","url":"https://pubmed.ncbi.nlm.nih.gov/32437331","citation_count":42,"is_preprint":false},{"pmid":"9271021","id":"PMC_9271021","title":"Hodgkin's cells express CD83, a dendritic cell lineage associated antigen.","date":"1997","source":"Pathology","url":"https://pubmed.ncbi.nlm.nih.gov/9271021","citation_count":41,"is_preprint":false},{"pmid":"19095953","id":"PMC_19095953","title":"CD83+CCR7- dendritic cells accumulate in the subepithelial dome and internalize translocated Escherichia coli HB101 in the Peyer's patches of ileal Crohn's disease.","date":"2008","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/19095953","citation_count":41,"is_preprint":false},{"pmid":"26311871","id":"PMC_26311871","title":"L Particles Transmit Viral Proteins from Herpes Simplex Virus 1-Infected Mature Dendritic Cells to Uninfected Bystander Cells, Inducing CD83 Downmodulation.","date":"2015","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/26311871","citation_count":41,"is_preprint":false},{"pmid":"15322158","id":"PMC_15322158","title":"A novel mutation in CD83 results in the development of a unique population of CD4+ T cells.","date":"2004","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/15322158","citation_count":40,"is_preprint":false},{"pmid":"11642602","id":"PMC_11642602","title":"Diverse functional activity of CD83+ monocyte-derived dendritic cells and the implications for cancer vaccines.","date":"2001","source":"Critical reviews in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/11642602","citation_count":40,"is_preprint":false},{"pmid":"19465512","id":"PMC_19465512","title":"Decreased small airway and alveolar CD83+ dendritic cells in COPD.","date":"2009","source":"Chest","url":"https://pubmed.ncbi.nlm.nih.gov/19465512","citation_count":40,"is_preprint":false},{"pmid":"15760381","id":"PMC_15760381","title":"CD83 monocyte-derived dendritic cells are present in human decidua and progesterone induces their differentiation in vitro.","date":"2005","source":"American journal of reproductive immunology (New York, N.Y. : 1989)","url":"https://pubmed.ncbi.nlm.nih.gov/15760381","citation_count":40,"is_preprint":false},{"pmid":"25204675","id":"PMC_25204675","title":"Dendritic cell CD83 homotypic interactions regulate inflammation and promote mucosal homeostasis.","date":"2014","source":"Mucosal immunology","url":"https://pubmed.ncbi.nlm.nih.gov/25204675","citation_count":39,"is_preprint":false},{"pmid":"22065790","id":"PMC_22065790","title":"CD83-stimulated monocytes suppress T-cell immune responses through production of prostaglandin E2.","date":"2011","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/22065790","citation_count":39,"is_preprint":false},{"pmid":"21079552","id":"PMC_21079552","title":"Prevention of chronic renal allograft rejection by soluble CD83.","date":"2010","source":"Transplantation","url":"https://pubmed.ncbi.nlm.nih.gov/21079552","citation_count":38,"is_preprint":false},{"pmid":"12857898","id":"PMC_12857898","title":"Latent membrane protein 1 of Epstein-Barr virus induces CD83 by the NF-kappaB signaling pathway.","date":"2003","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/12857898","citation_count":37,"is_preprint":false},{"pmid":"19542455","id":"PMC_19542455","title":"The transmembrane E3 ligase GRAIL ubiquitinates and degrades CD83 on CD4 T cells.","date":"2009","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/19542455","citation_count":37,"is_preprint":false},{"pmid":"37528070","id":"PMC_37528070","title":"Microglial expression of CD83 governs cellular activation and restrains neuroinflammation in experimental autoimmune encephalomyelitis.","date":"2023","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/37528070","citation_count":36,"is_preprint":false},{"pmid":"25563385","id":"PMC_25563385","title":"An immunohistochemical study of CD83- and CD1a-positive dendritic cells in the decidua of women with recurrent spontaneous abortion.","date":"2015","source":"European journal of medical research","url":"https://pubmed.ncbi.nlm.nih.gov/25563385","citation_count":36,"is_preprint":false},{"pmid":"31527313","id":"PMC_31527313","title":"CD83 orchestrates immunity toward self and non-self in dendritic cells.","date":"2019","source":"JCI insight","url":"https://pubmed.ncbi.nlm.nih.gov/31527313","citation_count":35,"is_preprint":false},{"pmid":"17911597","id":"PMC_17911597","title":"Unique features and distribution of the chicken CD83+ cell.","date":"2007","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/17911597","citation_count":35,"is_preprint":false},{"pmid":"34531862","id":"PMC_34531862","title":"Eubacterium rectale Attenuates HSV-1 Induced Systemic Inflammation in Mice by Inhibiting CD83.","date":"2021","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/34531862","citation_count":35,"is_preprint":false},{"pmid":"15481147","id":"PMC_15481147","title":"The soluble form of CD83 dramatically changes the cytoskeleton of dendritic cells.","date":"2004","source":"Immunobiology","url":"https://pubmed.ncbi.nlm.nih.gov/15481147","citation_count":35,"is_preprint":false},{"pmid":"15051893","id":"PMC_15051893","title":"Melanoma cells transfected to express CD83 induce antitumor immunity that can be increased by also engaging CD137.","date":"2004","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/15051893","citation_count":35,"is_preprint":false},{"pmid":"11412308","id":"PMC_11412308","title":"Detection of anaphylatoxin receptors on CD83+ dendritic cells derived from human skin.","date":"2001","source":"Immunology","url":"https://pubmed.ncbi.nlm.nih.gov/11412308","citation_count":34,"is_preprint":false},{"pmid":"12182451","id":"PMC_12182451","title":"Cloning and characterization of the promoter region of the human CD83 gene.","date":"2002","source":"Immunobiology","url":"https://pubmed.ncbi.nlm.nih.gov/12182451","citation_count":34,"is_preprint":false},{"pmid":"16102442","id":"PMC_16102442","title":"Upregulation of CD40, CD80, CD83 or CD86 on alveolar macrophages after lung transplantation.","date":"2005","source":"The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation","url":"https://pubmed.ncbi.nlm.nih.gov/16102442","citation_count":33,"is_preprint":false},{"pmid":"12950676","id":"PMC_12950676","title":"Enhanced activation of CD83-positive T cells.","date":"2003","source":"Scandinavian journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/12950676","citation_count":32,"is_preprint":false},{"pmid":"25151500","id":"PMC_25151500","title":"Murine CD83-positive T cells mediate suppressor functions in vitro and in vivo.","date":"2014","source":"Immunobiology","url":"https://pubmed.ncbi.nlm.nih.gov/25151500","citation_count":32,"is_preprint":false},{"pmid":"15721284","id":"PMC_15721284","title":"CD83 is a dimer: Comparative analysis of monomeric and dimeric isoforms.","date":"2005","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/15721284","citation_count":32,"is_preprint":false},{"pmid":"11922761","id":"PMC_11922761","title":"Overexpression, purification, and biochemical characterization of the extracellular human CD83 domain and generation of monoclonal antibodies.","date":"2002","source":"Protein expression and purification","url":"https://pubmed.ncbi.nlm.nih.gov/11922761","citation_count":31,"is_preprint":false},{"pmid":"27837105","id":"PMC_27837105","title":"The Analysis of CD83 Expression on Human Immune Cells Identifies a Unique CD83+-Activated T Cell Population.","date":"2016","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/27837105","citation_count":31,"is_preprint":false},{"pmid":"18713970","id":"PMC_18713970","title":"Induction of CD83+CD14+ nondendritic antigen-presenting cells by exposure of monocytes to IFN-alpha.","date":"2008","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/18713970","citation_count":30,"is_preprint":false},{"pmid":"31001257","id":"PMC_31001257","title":"Soluble CD83 Triggers Resolution of Arthritis and Sustained Inflammation Control in IDO Dependent Manner.","date":"2019","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/31001257","citation_count":28,"is_preprint":false},{"pmid":"24643878","id":"PMC_24643878","title":"Herpes simplex virus type 1 ICP0 induces CD83 degradation in mature dendritic cells independent of its E3 ubiquitin ligase function.","date":"2014","source":"The Journal of general virology","url":"https://pubmed.ncbi.nlm.nih.gov/24643878","citation_count":28,"is_preprint":false},{"pmid":"26286117","id":"PMC_26286117","title":"Immunosuppressive human anti-CD83 monoclonal antibody depletion of activated dendritic cells in transplantation.","date":"2015","source":"Leukemia","url":"https://pubmed.ncbi.nlm.nih.gov/26286117","citation_count":27,"is_preprint":false},{"pmid":"25800093","id":"PMC_25800093","title":"CD83 is required for the induction of protective immunity by a DNA vaccine in a teleost model.","date":"2015","source":"Developmental and comparative immunology","url":"https://pubmed.ncbi.nlm.nih.gov/25800093","citation_count":27,"is_preprint":false},{"pmid":"21277328","id":"PMC_21277328","title":"Activated T cells induce rapid CD83 expression on B cells by engagement of CD40.","date":"2011","source":"Immunology letters","url":"https://pubmed.ncbi.nlm.nih.gov/21277328","citation_count":27,"is_preprint":false},{"pmid":"9566553","id":"PMC_9566553","title":"Low CD83, but normal MHC class II and costimulatory molecule expression, on spleen dendritic cells from HIV+ patients.","date":"1998","source":"AIDS research and human retroviruses","url":"https://pubmed.ncbi.nlm.nih.gov/9566553","citation_count":27,"is_preprint":false},{"pmid":"24436459","id":"PMC_24436459","title":"Dendritic cell membrane CD83 enhances immune responses by boosting intracellular calcium release in T lymphocytes.","date":"2014","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/24436459","citation_count":26,"is_preprint":false},{"pmid":"16136499","id":"PMC_16136499","title":"Comparative analysis of CD1a, S-100, CD83, and CD11c human dendritic cells in normal, premalignant, and malignant tissues.","date":"2005","source":"Histology and histopathology","url":"https://pubmed.ncbi.nlm.nih.gov/16136499","citation_count":26,"is_preprint":false},{"pmid":"29351987","id":"PMC_29351987","title":"CD83 is a new potential biomarker and therapeutic target for Hodgkin lymphoma.","date":"2018","source":"Haematologica","url":"https://pubmed.ncbi.nlm.nih.gov/29351987","citation_count":25,"is_preprint":false},{"pmid":"36769151","id":"PMC_36769151","title":"CD83 Regulates the Immune Responses in Inflammatory Disorders.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36769151","citation_count":24,"is_preprint":false},{"pmid":"19234177","id":"PMC_19234177","title":"Engagement of CD83 on B cells modulates B cell function in vivo.","date":"2009","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/19234177","citation_count":24,"is_preprint":false},{"pmid":"23886695","id":"PMC_23886695","title":"Soluble human CD83 ameliorates lupus in NZB/W F1 mice.","date":"2013","source":"Immunobiology","url":"https://pubmed.ncbi.nlm.nih.gov/23886695","citation_count":24,"is_preprint":false},{"pmid":"26661374","id":"PMC_26661374","title":"CD1a+ and CD83+ Langerhans cells are reduced in lower lip squamous cell carcinoma.","date":"2015","source":"Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology","url":"https://pubmed.ncbi.nlm.nih.gov/26661374","citation_count":23,"is_preprint":false},{"pmid":"20561589","id":"PMC_20561589","title":"Expression of Scophthalmus maximus CD83 correlates with bacterial infection and antigen stimulation.","date":"2010","source":"Fish & shellfish immunology","url":"https://pubmed.ncbi.nlm.nih.gov/20561589","citation_count":23,"is_preprint":false},{"pmid":"10811479","id":"PMC_10811479","title":"CD83+ human dendritic cells transfected with tumor peptide cDNA by electroporation induce specific T-cell responses: A potential tool for gene immunotherapy.","date":"2000","source":"Cancer gene therapy","url":"https://pubmed.ncbi.nlm.nih.gov/10811479","citation_count":22,"is_preprint":false},{"pmid":"11937733","id":"PMC_11937733","title":"In situ localization of CD83-positive dendritic cells in psoriatic lesions.","date":"2002","source":"Dermatology (Basel, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/11937733","citation_count":22,"is_preprint":false},{"pmid":"37442138","id":"PMC_37442138","title":"High temperature inhibits vascular development via the PIF4-miR166-HB15 module in Arabidopsis.","date":"2023","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/37442138","citation_count":20,"is_preprint":false},{"pmid":"35054916","id":"PMC_35054916","title":"Tilting the Balance: Therapeutic Prospects of CD83 as a Checkpoint Molecule Controlling Resolution of Inflammation.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35054916","citation_count":20,"is_preprint":false},{"pmid":"17526743","id":"PMC_17526743","title":"Soluble CD14 and CD83 from human neonatal antigen-presenting cells are inducible by commensal bacteria and suppress allergen-induced human neonatal Th2 differentiation.","date":"2007","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/17526743","citation_count":20,"is_preprint":false},{"pmid":"28267648","id":"PMC_28267648","title":"Expression of soluble CD83 in plasma from early-stage rheumatoid arthritis patients is not modified by anti-TNF-α therapy.","date":"2017","source":"Cytokine","url":"https://pubmed.ncbi.nlm.nih.gov/28267648","citation_count":19,"is_preprint":false},{"pmid":"16841299","id":"PMC_16841299","title":"Transgenic expression of a CD83-immunoglobulin fusion protein impairs the development of immune-competent CD4-positive T cells.","date":"2006","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/16841299","citation_count":18,"is_preprint":false},{"pmid":"26561569","id":"PMC_26561569","title":"Triple costimulation via CD80, 4-1BB, and CD83 ligand elicits the long-term growth of Vγ9Vδ2 T cells in low levels of IL-2.","date":"2015","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/26561569","citation_count":18,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":47156,"output_tokens":6754,"usd":0.121389},"stage2":{"model":"claude-opus-4-6","input_tokens":10503,"output_tokens":4511,"usd":0.247935},"total_usd":0.369324,"stage1_batch_id":"msgbatch_011kfMfE81o6CTcyhVUqumuW","stage2_batch_id":"msgbatch_01DTputS6WNkH745x1nVSoBo","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2011,\n      \"finding\": \"The transmembrane domain of CD83 blocks IL-10-driven MARCH1-mediated ubiquitination and degradation of MHC class II and CD86 on dendritic cells, thereby stabilizing surface MHC II and CD86 expression.\",\n      \"method\": \"N-ethyl-N-nitrosourea-induced mouse mutation eliminating CD83 transmembrane region; genetic epistasis with MARCH1; functional rescue experiments\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — in vivo genetic epistasis with defined molecular mechanism, multiple orthogonal approaches\",\n      \"pmids\": [\"21220452\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"In cortical thymic epithelial cells (cTECs), CD83's transmembrane domain is necessary and sufficient for thymic CD4 T cell selection by antagonizing the E3 ubiquitin ligase March8 (not March1) to stabilize MHC II on cTECs.\",\n      \"method\": \"Viral reconstitution of CD83 gene function in thymic epithelial cells; Cd83-/- mice rescued by ablating March8; ubiquitination-resistant MHCII variant rescue\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal genetic rescue experiments, identifies specific E3 ligase substrate relationship\",\n      \"pmids\": [\"27503071\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"CD83 expression by thymic epithelial and dendritic cells is required for CD4+ single-positive thymocyte development; CD83-deficient mice show a specific block in CD4+ T cell generation, and wild-type thymocytes fail to develop into CD4+ T cells in CD83-/- hosts.\",\n      \"method\": \"CD83-knockout mice; bone marrow and thymocyte transfer experiments\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with defined cellular phenotype replicated with adoptive transfer, published in high-impact journal\",\n      \"pmids\": [\"11955430\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Soluble CD83 (sCD83) binds to MD-2, the co-receptor of the TLR4/MD-2 complex on CD14+ monocytes, rapidly degrades IRAK-1, and induces anti-inflammatory mediators IDO, IL-10, and PGE2 in a COX-2-dependent manner, thereby suppressing T cell proliferation and IL-2 secretion.\",\n      \"method\": \"Binding assays identifying MD-2 as sCD83 partner; IRAK-1 degradation assays; pharmacological inhibition of COX-2; T cell proliferation assays\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — receptor identification plus downstream signaling mechanism, multiple orthogonal methods\",\n      \"pmids\": [\"28193829\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"HSV-1 immediate-early protein ICP0 drives proteasome-mediated degradation of CD83 in mature dendritic cells, with the RING finger E3 ubiquitin ligase activity of ICP0 required; proteasome inhibition restores CD83 surface expression.\",\n      \"method\": \"HSV-1 ICP0 deletion mutant infection; ICP0/CD83 co-transfection in 293T cells; RING finger mutant ICP0; proteasome inhibitor treatment; FACS and Western blot\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple genetic and pharmacological approaches in same study demonstrating mechanism\",\n      \"pmids\": [\"17428858\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"HSV-1 ICP0 alone is sufficient to degrade CD83 in mature dendritic cells, but this degradation is independent of ICP0's E3 ubiquitin ligase domain and independent of lysine ubiquitination, suggesting a distinct proteasomal degradation mechanism.\",\n      \"method\": \"Expression of ICP0 mutants lacking E3 ubiquitin ligase domain; E1 activating enzyme inhibitor; infection experiments in mDCs\",\n      \"journal\": \"The Journal of general virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — single study with multiple mutant constructs, but partially contradicts prior finding on ICP0 RING domain requirement\",\n      \"pmids\": [\"24643878\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"HSV-1 L particles (containing viral proteins but lacking capsid and DNA) transfer viral proteins from infected mature dendritic cells to uninfected bystander DCs, inducing CD83 downmodulation in the absence of productive infection.\",\n      \"method\": \"L particle isolation and incubation with uninfected mDCs; transwell exclusion of phagocytosis; FACS analysis of CD83\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — mechanistic demonstration with isolated L particles and multiple controls\",\n      \"pmids\": [\"26311871\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The transmembrane RING finger E3 ubiquitin ligase GRAIL ubiquitinates CD83 on lysine residues K168 and K183 (but not K192) in its cytoplasmic domain, targeting it for 26S proteasome-mediated degradation in CD4+ T cells; GRAIL-mediated CD83 downregulation requires intact extracellular protease-associated and RING domains.\",\n      \"method\": \"Retroviral GRAIL transduction; RNA interference knockdown; site-directed mutagenesis of CD83 lysines; proteasome inhibitor assays; in vitro ubiquitination\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstituted ubiquitination with mutagenesis identifying specific lysines, multiple orthogonal methods\",\n      \"pmids\": [\"19542455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"HCMV infection of mature monocyte-derived dendritic cells causes shedding of CD83 from the cell surface into the supernatant as soluble CD83, and this soluble CD83 accounts for the immunosuppressive activity of infected DC supernatants on normal DC-mediated T cell stimulation.\",\n      \"method\": \"CD83 immunodepletion from HCMV-infected moDC supernatants; virion-depleted supernatant transfer; Western blot; ELISA\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — immunodepletion demonstrates causality, single lab\",\n      \"pmids\": [\"14962896\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"CD83 functions as an adhesion receptor; its soluble extracellular domain binds to monocytes and a subset of activated CD8+ T cells via a 72 kDa sialic acid-dependent counter-receptor; neuraminidase treatment abolishes binding.\",\n      \"method\": \"CD83-Ig fusion protein binding assays; immunoprecipitation of 72 kDa counter-receptor; neuraminidase treatment; CD83-transfected carcinoma cell adhesion assay\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP and functional binding assays identifying counter-receptor properties, single lab\",\n      \"pmids\": [\"11238630\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Soluble CD83 released from activated dendritic cells and B lymphocytes is generated by shedding of membrane CD83 (inhibition of protein synthesis does not prevent short-term sCD83 release); it is detectable in normal human serum.\",\n      \"method\": \"sCD83-specific ELISA; Western blotting; cycloheximide inhibition of protein synthesis; mCD83+ and mCD83- cell line comparison\",\n      \"journal\": \"International immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological dissection of shedding mechanism, multiple methods\",\n      \"pmids\": [\"11431426\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"CD83 is preformed as an intracellular protein in immature DCs, monocytes, and macrophages; its rapid surface expression upon activation is post-translationally regulated, requires glycosylation (blocked by tunicamycin), and occurs via a brefeldin A-sensitive (secretory pathway) but cycloheximide-insensitive (pre-existing protein) mechanism. Mature DCs express a 50 kDa glycoform while immature cells express a 37 kDa form.\",\n      \"method\": \"Western blotting; indirect immunofluorescence; brefeldin A, cycloheximide, and tunicamycin treatment; PNGase F digestion; flow cytometry\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple pharmacological and biochemical approaches establishing post-translational regulation mechanism\",\n      \"pmids\": [\"15320871\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"CD83 mRNA contains a novel cis-acting post-transcriptional regulatory element in its coding region that binds the RNA-binding protein HuR; HuR is required for cytoplasmic accumulation of CD83 mRNA via the CRM1 nuclear export pathway, and this process depends on the nucleoporin Nup214/CAN.\",\n      \"method\": \"RNA interference knockdown of HuR; transient transfection with CD83 cis-element constructs; leptomycin B (CRM1 inhibitor) treatment; dominant-negative Nup214/CAN overexpression; RNA stability assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods identifying specific RNA element, binding protein, and export pathway\",\n      \"pmids\": [\"16484227\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"The HuR ligand APRIL (ANP32B) contributes to nuclear export and subsequent translation of CD83 mRNA; phosphorylation of APRIL at threonine 244 regulates its nuclear export, and APRIL knockdown reduces cytoplasmic CD83 mRNA levels.\",\n      \"method\": \"RNA interference knockdown of APRIL; identification of NLS and NES of APRIL; phosphorylation site mapping by mutagenesis; subcellular fractionation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — RNAi plus mutagenesis in single study\",\n      \"pmids\": [\"17178712\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"CD83 can be expressed as soluble forms generated by alternative splicing of CD83 mRNA; at least one splice variant is efficiently translated into protein, and recombinant soluble CD83 strongly inhibits T cell proliferation in mixed lymphocyte reactions.\",\n      \"method\": \"RT-PCR cloning and sequence analysis of CD83 transcripts from PBMCs; recombinant protein expression; MLR inhibition assays\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — transcript characterization plus functional assay, single lab\",\n      \"pmids\": [\"15905506\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"CD83 is a disulfide-linked dimer; the fifth cysteine residue at amino acid position 129 in the extracellular Ig domain mediates dimerization via an intermolecular disulfide bond, and a C129S mutant monomeric form retains inhibitory activity on DC maturation and allogeneic T cell stimulation in MLR.\",\n      \"method\": \"Recombinant mutagenesis (C129S substitution); non-reducing SDS-PAGE; MLR assays; DC maturation assays\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 — mutagenesis combined with biochemical and functional assays, single study\",\n      \"pmids\": [\"15721284\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"The CD83 promoter contains four SP1 binding sites and one NF-κB element; NF-κB factors specifically bind the NF-κB element (confirmed by EMSA), and promoter activity is inducible by TNF-α in a manner strictly dependent on the intact NF-κB element.\",\n      \"method\": \"Promoter deletion constructs; luciferase reporter assays; electrophoretic mobility shift assays (EMSA); TNF-α stimulation\",\n      \"journal\": \"Immunobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 — EMSA and functional promoter mutagenesis, single lab\",\n      \"pmids\": [\"12182451\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"EBV latent membrane protein 1 (LMP1) induces CD83 expression in B cells via NF-κB activation; LMP1 mutant studies and luciferase reporter assays with the CD83 promoter demonstrated NF-κB dependence; signaling through CD40, TNF-R1, or TNF-R2 intracellular domains fused to LMP1 transmembrane domain similarly activates the CD83 promoter.\",\n      \"method\": \"Inducible LMP1 expression system (NGFR-LMP1 fusion); luciferase reporter assays with CD83 promoter and LMP1 mutants; EBNA2-inducible LCL system\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic constructs establishing NF-κB as the upstream transcriptional activator of CD83 in B cells\",\n      \"pmids\": [\"12857898\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CD83 on monocytes, when stimulated by CD83 (membrane CD83 on DCs or T cells), induces COX-2-dependent PGE2 production via NF-κB activation, and this PGE2 mediates T cell suppression (inhibiting IL-2 and IFN-γ); COX-2-selective inhibitor NS-398 fully prevented CD83-triggered T cell inhibition.\",\n      \"method\": \"COX-2 inhibitor (NS-398) treatment; NF-κB pathway analysis; ELISA for PGE2 and cytokines; T cell proliferation assays with monocyte co-cultures\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological epistasis with multiple readouts, single lab\",\n      \"pmids\": [\"22065790\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"CD83 homotypic interactions between dendritic cells (via cell-cell contact) inhibit pro-inflammatory responses by suppressing p38α phosphorylation in the MAPK pathway; CD83 cytoplasmic truncation or knockdown abolishes this homotypic inhibitory signaling.\",\n      \"method\": \"DC conditional knockout of CD83; CD83 overexpression; CD83 knockdown; cytoplasmic truncation mutants; p38α phosphorylation assays; in vitro and in vivo colitis models\",\n      \"journal\": \"Mucosal immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — domain-specific mutants establishing signaling mechanism, multiple methods, single lab\",\n      \"pmids\": [\"25204675\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"CD83 knockdown by siRNA in human monocyte-derived DCs significantly reduces DC-mediated T cell proliferation and alters cytokine expression during T cell priming, demonstrating CD83's role as an enhancer of T cell stimulatory capacity.\",\n      \"method\": \"siRNA electroporation into immature DCs; flow cytometry; allogeneic T cell proliferation assays; cytokine measurements\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — specific RNAi knockdown with functional readout, single lab\",\n      \"pmids\": [\"17442926\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Retroviral transduction of CD83 into naive CD4+CD25- T cells induces a regulatory phenotype including Foxp3 expression; CD83+Foxp3+ T cells suppress contact hypersensitivity and prevent EAE in vivo, reducing IFN-γ and IL-17 while increasing IL-10.\",\n      \"method\": \"Retroviral transduction of CD83 into T cells; adoptive transfer into EAE and contact hypersensitivity models; cytokine measurement\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — gain-of-function with in vivo functional readout, single lab\",\n      \"pmids\": [\"18424708\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Treg-intrinsic CD83 expression is essential for Treg differentiation upon activation; conditional Treg-specific CD83 knockout mice develop a pro-inflammatory phenotype with loss of Treg-specific differentiation markers and induction of an inflammatory profile.\",\n      \"method\": \"Treg-specific conditional CD83 knockout mice; scRNA-seq; flow cytometry; autoimmunity models\",\n      \"journal\": \"JCI insight\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with defined cellular phenotype, single lab\",\n      \"pmids\": [\"29875316\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"DC-specific conditional CD83 knockout DCs produce drastically increased IL-2, higher CD25 and OX40L expression, causing superior T cell responses and compromised Treg suppressive functions; CD83-deficient DCs express increased IL-12 after bacterial encounter, leading to accelerated immune responses and exacerbated autoimmunity in EAE.\",\n      \"method\": \"DC-specific CD83 conditional KO (CD83ΔDC) mice; bacterial infection models (Salmonella, Listeria); EAE model; flow cytometry; cytokine measurements\",\n      \"journal\": \"JCI insight\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — cell-type-specific KO with multiple functional readouts, single lab\",\n      \"pmids\": [\"31527313\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"B cell-specific CD83 knockout B cells show defective upregulation of MHC class II and CD86 after stimulation, impaired proliferation, a shift toward increased dark zone GC B cells, and enhanced IgE responses; CD83-deficient B cells have a competitive disadvantage in GC responses.\",\n      \"method\": \"B cell-specific CD83 conditional KO mice; mixed BM chimeras; GC analysis by flow cytometry; immunization experiments; Borrelia burgdorferi infection model\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — cell-type-specific KO with multiple functional readouts, single lab\",\n      \"pmids\": [\"26983787\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Activated T cells induce CD83 expression on B cells through CD40 engagement (not TCR/MHC binding or soluble factors), as demonstrated by anti-CD40L antibody blockade and transwell experiments.\",\n      \"method\": \"T cell receptor transgenic mice; transwell co-culture; anti-CD40L antibody blockade; in vivo peptide injection; flow cytometry\",\n      \"journal\": \"Immunology letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — receptor blockade and contact-dependency experiments establishing CD40-CD40L as the induction signal\",\n      \"pmids\": [\"21277328\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Soluble CD83 treatment of mature DCs completely alters their cytoskeleton (assessed by phalloidin, tubulin, and fascin staining), causing cell rounding and loss of veils, and completely inhibits DC-T cell cluster formation.\",\n      \"method\": \"Phalloidin, tubulin, and fascin immunofluorescence staining; DC-T cell clustering assays; recombinant sCD83 treatment\",\n      \"journal\": \"Immunobiology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — single lab, descriptive morphological readout without defined molecular mechanism\",\n      \"pmids\": [\"15481147\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CD83 expression in murine microglia is associated with pro-resolving functions; conditional deletion of CD83 in microglia results in an over-activated state during EAE neuroinflammation, with increased recruitment of pathogenic immune cells to the CNS and exacerbated disease.\",\n      \"method\": \"Conditional microglia-specific CD83 KO mice; EAE model; single-cell RNA-sequencing; flow cytometry of CNS infiltrates\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — cell-type-specific KO with scRNA-seq and functional in vivo readout\",\n      \"pmids\": [\"37528070\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Membrane CD83 on mature DCs enhances intracellular calcium release in T lymphocytes upon DC-T cell contact; CD83 knockdown or antibody blockade reduces calcium signal amplitude and T cell proliferation.\",\n      \"method\": \"siRNA knockdown of CD83; anti-CD83 antibody blockade; Fluo-4-AM calcium indicator; flow cytometry and confocal microscopy; CFSE proliferation assay; calcium chelation\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — two independent perturbation approaches (RNAi and antibody) with calcium signaling readout\",\n      \"pmids\": [\"24436459\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Soluble CD83 enhances resolution of antigen-induced arthritis by reducing IL-17A, IFN-γ, IL-6, TNF-α, and RANKL in joints; this mechanism is IDO-dependent (abrogated by 1-methyltryptophan) and also involves TGF-β (blocked by anti-TGF-β antibodies), with induction of regulatory T cells.\",\n      \"method\": \"Mouse AIA model; IDO inhibitor (1-methyltryptophan); anti-TGF-β antibody blockade; flow cytometry of Tregs; cytokine measurement; histological analysis of bone destruction\",\n      \"journal\": \"Frontiers in immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological epistasis with multiple pathway inhibitors and functional readouts, single lab\",\n      \"pmids\": [\"31001257\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CD83 is a transmembrane immunoglobulin superfamily glycoprotein expressed on mature dendritic cells, activated lymphocytes, and regulatory T cells that functions as an immune checkpoint: its transmembrane domain stabilizes surface MHC II and CD86 by blocking ubiquitin E3 ligases MARCH1 (in DCs) and March8 (in cortical thymic epithelial cells), thereby enabling CD4+ T cell selection; its expression is post-translationally regulated by glycosylation and at the mRNA level through a HuR/CRM1-dependent nuclear export pathway; its promoter is activated by NF-κB (induced by TNF-α and viral LMP1); HSV-1 ICP0 drives proteasomal degradation of CD83 as a viral immune escape mechanism; GRAIL ubiquitinates CD83 at K168/K183 for proteasomal degradation in anergic CD4+ T cells; membrane CD83 enhances T cell activation by boosting intracellular calcium release; soluble CD83 (generated by alternative splicing and shedding) exerts immunosuppressive effects by binding MD-2 within the TLR4/MD-2 complex on monocytes to induce IDO, IL-10, and PGE2 production, and by engaging CD40 to regulate B cell antibody responses; CD83 expression in DCs, Tregs, and microglia restrains excessive inflammation and promotes immune tolerance.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CD83 is an immunoglobulin superfamily glycoprotein that functions as a central regulator of antigen presentation and immune tolerance across dendritic cells, B cells, regulatory T cells, and microglia. Its transmembrane domain stabilizes surface MHC class II and CD86 by antagonizing MARCH1-mediated ubiquitination in dendritic cells and March8-mediated ubiquitination in cortical thymic epithelial cells, a mechanism essential for CD4+ T cell thymic selection and peripheral T cell priming [PMID:21220452, PMID:27503071, PMID:11955430]. Soluble CD83, generated by both alternative splicing and proteolytic shedding, exerts immunosuppressive effects by binding MD-2 in the TLR4/MD-2 complex on monocytes to induce IDO, IL-10, and PGE2 production, and CD83 expression in Tregs, DCs, and microglia restrains inflammatory responses, as conditional deletion in each lineage results in exacerbated autoimmunity [PMID:28193829, PMID:29875316, PMID:31527313, PMID:37528070]. CD83 protein levels are regulated post-translationally by glycosylation-dependent trafficking from preformed intracellular stores, by GRAIL-mediated ubiquitination at K168/K183 in anergic T cells, and by HSV-1 ICP0-directed proteasomal degradation as a viral immune evasion strategy [PMID:15320871, PMID:19542455, PMID:17428858].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Establishing that CD83 has a ligand-binding function: the extracellular domain was shown to engage a 72 kDa sialic acid-dependent counter-receptor on monocytes and activated CD8+ T cells, and that membrane CD83 is shed to produce a soluble form detectable in serum, framing CD83 as both a membrane receptor and a released immunomodulator.\",\n      \"evidence\": \"CD83-Ig fusion protein binding assays with neuraminidase treatment; sCD83-specific ELISA with cycloheximide blockade showing shedding mechanism\",\n      \"pmids\": [\"11238630\", \"11431426\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Identity of the 72 kDa counter-receptor was not determined\", \"Protease responsible for shedding not identified\", \"Physiological relevance of serum sCD83 levels not established\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Demonstrating that CD83 is non-redundantly required for CD4+ T cell development: CD83-knockout mice showed a specific block in CD4+ single-positive thymocyte generation, and the defect mapped to thymic stromal cells rather than thymocytes, establishing CD83 as essential for thymic positive selection.\",\n      \"evidence\": \"CD83-knockout mice with bone marrow and thymocyte adoptive transfer experiments\",\n      \"pmids\": [\"11955430\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism by which CD83 promotes CD4 selection was unknown\", \"Whether CD83 acted on MHC II stability or via a signaling pathway was unresolved\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Defining the transcriptional regulation of CD83: the promoter was shown to be NF-κB-dependent and TNF-α-inducible, and EBV LMP1 was later shown to activate CD83 transcription through the same NF-κB element, linking viral latency to CD83 upregulation in B cells.\",\n      \"evidence\": \"Promoter deletion/reporter assays with EMSA; LMP1 mutant and chimeric receptor reporter assays\",\n      \"pmids\": [\"12182451\", \"12857898\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Other transcription factors contributing to cell-type-specific CD83 expression were not characterized\", \"Epigenetic regulation not examined\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Resolving how CD83 surface expression is so rapidly induced: preformed CD83 protein exists intracellularly in immature DCs and is trafficked to the surface upon activation through a glycosylation-dependent, secretory-pathway mechanism that does not require new protein synthesis, revealing post-translational rather than transcriptional control as the primary switch.\",\n      \"evidence\": \"Brefeldin A, cycloheximide, and tunicamycin treatment of DCs; PNGase F digestion; flow cytometry and Western blot\",\n      \"pmids\": [\"15320871\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Glycosyltransferases responsible for the 37→50 kDa modification not identified\", \"Signal triggering ER-to-surface trafficking not defined\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Characterizing alternative forms of soluble CD83: alternative splicing was identified as a second source (beyond shedding) of soluble CD83, and the soluble protein was shown to potently inhibit T cell proliferation, while structural analysis revealed CD83 forms a disulfide-linked dimer via C129, though dimerization is dispensable for immunosuppressive function.\",\n      \"evidence\": \"RT-PCR cloning of splice variants; recombinant sCD83 in MLR; C129S mutagenesis with non-reducing SDS-PAGE\",\n      \"pmids\": [\"15905506\", \"15721284\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Relative contributions of splicing versus shedding to sCD83 pools in vivo unknown\", \"Whether dimerization affects receptor binding affinity not tested\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Uncovering a post-transcriptional regulatory circuit: CD83 mRNA contains a cis-acting element bound by HuR, which mediates CRM1/Nup214-dependent nuclear export; the HuR co-factor APRIL/ANP32B further promotes this export in a phosphorylation-dependent manner, establishing mRNA export as a rate-limiting step in CD83 expression.\",\n      \"evidence\": \"HuR and APRIL RNAi; leptomycin B treatment; dominant-negative Nup214; phosphorylation site mutagenesis\",\n      \"pmids\": [\"16484227\", \"17178712\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether this mRNA export mechanism operates in all CD83-expressing cell types not tested\", \"Kinase phosphorylating APRIL T244 not identified\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Identifying viral immune evasion targeting CD83: HSV-1 ICP0 was shown to drive proteasomal degradation of CD83 in mature DCs, initially attributed to ICP0's RING finger E3 ligase activity, though a subsequent study found degradation to be independent of this domain, leaving the precise mechanism debated.\",\n      \"evidence\": \"HSV-1 ICP0 deletion/RING mutants; proteasome inhibitor rescue; FACS and Western blot in mDCs and 293T cells\",\n      \"pmids\": [\"17428858\", \"24643878\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether ICP0 directly ubiquitinates CD83 or recruits another E3 ligase is unresolved\", \"The contradictory findings on RING domain requirement have not been reconciled\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Defining a T cell-intrinsic ubiquitin-dependent degradation pathway for CD83: GRAIL was identified as the E3 ligase ubiquitinating CD83 at K168 and K183 for proteasomal degradation in CD4+ T cells, providing a molecular mechanism for CD83 downregulation during T cell anergy.\",\n      \"evidence\": \"Retroviral GRAIL transduction; site-directed mutagenesis of CD83 lysines; in vitro ubiquitination assay; proteasome inhibitor rescue\",\n      \"pmids\": [\"19542455\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether GRAIL targets CD83 in vivo during anergy induction not demonstrated\", \"Signals coupling anergy to GRAIL-CD83 interaction not defined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Solving the molecular mechanism of CD83 in MHC II stabilization: the transmembrane domain of CD83 was shown to block MARCH1-mediated ubiquitination and degradation of MHC II and CD86 on DCs, establishing CD83 as a competitive inhibitor of MARCH E3 ligases rather than a conventional signaling receptor.\",\n      \"evidence\": \"ENU-induced CD83 transmembrane mutant mice; genetic epistasis with MARCH1 knockout; functional rescue\",\n      \"pmids\": [\"21220452\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether CD83 TMD directly binds MARCH1 TMD or acts indirectly not determined\", \"Stoichiometry of CD83–MARCH1 interaction unknown\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Identifying the signal inducing CD83 on B cells and a downstream immunosuppressive effector: CD40 engagement by T cells was shown to drive CD83 upregulation on B cells, and membrane CD83 engagement on monocytes triggers COX-2-dependent PGE2 production via NF-κB, mediating T cell suppression.\",\n      \"evidence\": \"Anti-CD40L blockade and transwell experiments; COX-2 inhibitor NS-398 treatment with cytokine and proliferation assays\",\n      \"pmids\": [\"21277328\", \"22065790\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct receptor for membrane CD83 on monocytes not identified at this stage\", \"Whether PGE2 pathway operates in vivo not shown\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Demonstrating that membrane CD83 actively promotes T cell activation through calcium signaling and that homotypic DC–DC CD83 interactions suppress inflammation via p38α: these findings revealed CD83 has dual context-dependent functions—costimulatory in DC–T cell contact and inhibitory in DC–DC contact.\",\n      \"evidence\": \"CD83 siRNA and anti-CD83 antibody with Fluo-4-AM calcium imaging; CD83 cytoplasmic truncation mutants with p38α phosphorylation assays in colitis models\",\n      \"pmids\": [\"24436459\", \"25204675\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"T cell receptor for membrane CD83 not identified\", \"Whether cytoplasmic domain signals directly or via adaptor proteins unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Extending the MARCH-antagonism model to thymic selection: in cortical thymic epithelial cells, CD83 TMD antagonizes March8 (not March1) to stabilize MHC II, directly explaining the CD4+ T cell selection defect in CD83-knockout mice identified 14 years earlier.\",\n      \"evidence\": \"Cd83−/− cTEC reconstitution; March8 ablation rescue; ubiquitination-resistant MHC II variant rescue in CD83-deficient thymus\",\n      \"pmids\": [\"27503071\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether CD83 TMD binds March8 directly or competes for substrate access not resolved\", \"Structural basis of E3 ligase selectivity (March1 in DCs vs March8 in cTECs) unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Establishing a B cell-intrinsic role for CD83: B cell-specific CD83 deletion revealed impaired MHC II and CD86 upregulation, defective germinal center responses, and dysregulated IgE production, extending the MARCH-antagonism paradigm to the B cell lineage.\",\n      \"evidence\": \"B cell-specific CD83 conditional KO mice; mixed bone marrow chimeras; immunization and infection models\",\n      \"pmids\": [\"26983787\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Which MARCH family member CD83 antagonizes in B cells not determined\", \"Whether GC phenotype is solely due to MHC II instability or additional pathways unclear\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Identifying the receptor for soluble CD83: sCD83 was shown to bind MD-2 within the TLR4/MD-2 complex on monocytes, triggering IRAK-1 degradation and inducing IDO, IL-10, and PGE2, providing a unified molecular explanation for the immunosuppressive activity of sCD83.\",\n      \"evidence\": \"Direct binding assays identifying MD-2; IRAK-1 degradation kinetics; COX-2 inhibition; T cell proliferation assays\",\n      \"pmids\": [\"28193829\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether sCD83 competes with LPS for MD-2 binding not addressed\", \"Crystal structure of sCD83–MD-2 complex not available\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstrating Treg-intrinsic requirement for CD83: conditional Treg-specific CD83 deletion caused loss of Treg differentiation markers and a pro-inflammatory phenotype, establishing that CD83 is not merely a Treg marker but functions cell-autonomously in Treg identity and suppressive capacity.\",\n      \"evidence\": \"Treg-specific conditional CD83 KO mice; scRNA-seq; autoimmunity phenotyping\",\n      \"pmids\": [\"29875316\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether Treg CD83 acts via MARCH antagonism or an independent mechanism not determined\", \"Direct target of CD83 signaling within Tregs unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Extending CD83's immune-regulatory role to DCs and demonstrating sCD83 therapeutic mechanism: DC-specific CD83 deletion caused hyperactivated DCs with excess IL-2 and IL-12 production leading to exacerbated autoimmunity, while sCD83 resolved arthritis via IDO- and TGF-β-dependent Treg induction.\",\n      \"evidence\": \"DC-specific CD83 conditional KO in EAE and infection models; sCD83 treatment in antigen-induced arthritis with IDO inhibitor and anti-TGF-β blockade\",\n      \"pmids\": [\"31527313\", \"31001257\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether DC CD83 restraint operates through MARCH1 antagonism or additional pathways not fully resolved\", \"Pharmacokinetics and in vivo receptor engagement of sCD83 not characterized\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Extending CD83 immune-regulatory function to the CNS: microglia-specific CD83 deletion led to over-activated microglia and exacerbated neuroinflammation in EAE, demonstrating that CD83's tolerance-promoting role extends beyond classical adaptive immune cells to CNS-resident innate immune cells.\",\n      \"evidence\": \"Conditional microglia-specific CD83 KO mice; EAE model; single-cell RNA-seq; CNS infiltrate analysis\",\n      \"pmids\": [\"37528070\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether microglial CD83 antagonizes a MARCH ligase or acts via a distinct mechanism unknown\", \"Microglial CD83 ligand or signaling partners not identified\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the structural basis of CD83 transmembrane domain interaction with MARCH E3 ligases, the identity of the membrane CD83 counter-receptor on T cells, whether MARCH antagonism fully explains CD83 function in Tregs and microglia, and the in vivo therapeutic potential of sCD83 via the MD-2 axis.\",\n      \"evidence\": \"Open questions from the accumulated literature\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of CD83 TMD–MARCH interaction exists\", \"T cell counter-receptor for membrane CD83 remains unidentified\", \"Cell-type-specific mechanisms beyond MARCH antagonism are undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 24]},\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [3, 18]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 1, 11, 28]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [3, 10, 14]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [11]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 1, 2, 3, 22, 23, 27]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 1, 7]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 18, 19]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"MARCH1\",\n      \"MARCH8\",\n      \"LY96\",\n      \"RNF128\",\n      \"ELAVL1\",\n      \"CD40\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}