{"gene":"LRCH1","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2017,"finding":"LRCH1 competes with Cdc42 for binding to DOCK8, thereby restraining DOCK8's guanine-nucleotide exchange factor (GEF) activity toward Cdc42 and inhibiting T cell migration. In response to chemokine stimulation, PKCα phosphorylates DOCK8 at three serine sites, promoting DOCK8 dissociation from LRCH1 and translocation to the leading edge. Point mutations at the DOCK8 serine sites block chemokine- and PKCα-induced T cell migration. Lrch1-deficient mice display more severe experimental autoimmune encephalomyelitis (EAE), while Lrch1 transgenic mice are protected, establishing LRCH1 as a negative regulator of the PKCα–DOCK8–Cdc42 migration module.","method":"Two-hybrid screening, co-immunoprecipitation, point mutagenesis of DOCK8 serine sites, Lrch1 transgenic and knockout mouse EAE model, directional migration assays","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal binding assays, mutagenesis of functional sites, and in vivo genetic models (KO and transgenic) with defined phenotypic readout, all in one study","pmids":["28028151"],"is_preprint":false},{"year":2020,"finding":"LRCH1 directly binds the transmembrane adapter protein LAT, reduces LAT phosphorylation, reduces LAT interaction with GRB2, and promotes LAT endocytosis, thereby dampening LAT signalosome formation and CD8+ T cell activation. Lrch1-knockout mice show enhanced CD8+ T cell proliferation and cytotoxicity against influenza virus, Listeria, and B16 tumor cells. Knockout of LRCH1 in human CAR T cells improved their migration and proliferation in vitro.","method":"Co-immunoprecipitation (direct LRCH1–LAT binding), phosphorylation assays, endocytosis assays, Lrch1-/- mouse infection and tumor models, adoptive transfer of Lrch1-/- CD8+ CTLs, LRCH1 KO in human CAR T cells","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct binding assay, multiple functional readouts (phosphorylation, endocytosis, in vivo tumor and infection models), genetic KO with defined phenotypes","pmids":["32727906"],"is_preprint":false},{"year":2020,"finding":"LRCH1 knockdown in microglia increased production of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) after LPS/ATP priming, promoted polarization toward iNOS-expressing (pro-inflammatory) microglia, enhanced microglia-mediated N27 neuron death, and increased activation of p38 MAPK and Erk1/2 signaling. Adoptive injection of LRCH1-knockdown microglia into rat spinal cords worsened post-SCI inflammation, tissue damage, and locomotor function, establishing LRCH1 as a negative regulator of microglia-mediated neuroinflammation via p38 MAPK and Erk1/2 pathways.","method":"Lentivirus-mediated LRCH1 knockdown in primary microglia, cytokine ELISA/qPCR, flow cytometry for polarization markers, p38 MAPK and Erk1/2 phosphorylation assays, adoptive transfer into rat SCI model with behavioral and histological readouts","journal":"Journal of neuroinflammation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro knockdown with pathway readouts and in vivo adoptive transfer model, single lab, multiple orthogonal methods","pmids":["32631435"],"is_preprint":false},{"year":2020,"finding":"LRCH1 inhibits NK-92 cell cytotoxicity against tumor cells. LRCH1 knockout (CRISPR-Cas9) did not affect basal NK-92 cell survival or natural cytotoxicity receptor expression, but upon tumor cell contact increased production of IFN-γ, TNF-α, IL-2, and granzyme B, and enhanced Src and Lck kinase activation. Primary human NK cells showed similar cytokine increases upon LRCH1 knockout, identifying Src/Lck signaling as the pathway negatively regulated by LRCH1 in NK cells.","method":"CRISPR-Cas9 knockout of LRCH1 in NK-92 cells and primary human NK cells, cytokine/granzyme B measurement, Src and Lck kinase activation assays, in vivo tumor killing assay","journal":"Immunobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean CRISPR KO with defined signaling (Src/Lck) and functional (cytotoxicity) readouts, single lab","pmids":["32173150"],"is_preprint":false},{"year":2020,"finding":"LRCH1 inhibits the migratory capacity of CD4+ T cells toward CXCL12. Lentiviral overexpression or knockdown of LRCH1 did not affect CD4+ T cell differentiation or related cytokine expression, but modulated chemotaxis in a PKCα-dependent manner, placing LRCH1 upstream of PKCα in CD4+ T cell migration.","method":"Lentiviral LRCH1 overexpression and knockdown in peripheral blood CD4+ T cells, Transwell chemotaxis assay toward CXCL12, flow cytometry for differentiation markers, cytokine ELISA/qPCR","journal":"International journal of medical sciences","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — clean gain- and loss-of-function with defined migratory phenotype and PKCα pathway placement, single lab","pmids":["32210709"],"is_preprint":false}],"current_model":"LRCH1 is a multifunctional negative regulator of immune cell migration and cytotoxicity: it restrains T cell migration by competing with Cdc42 for DOCK8 binding (disrupted by PKCα-mediated DOCK8 phosphorylation), suppresses CD8+ T cell and NK cell activation by binding LAT and attenuating Src/Lck signaling, inhibits CD4+ T cell chemotaxis via PKCα, and dampens microglial neuroinflammation through p38 MAPK and Erk1/2 pathways."},"narrative":{"mechanistic_narrative":"LRCH1 is a cytoplasmic adaptor protein that acts as a negative regulator of immune cell migration and effector activation across multiple cell types [PMID:28028151, PMID:32727906]. In T cells it restrains directional migration by sequestering the guanine-nucleotide exchange factor DOCK8 and competing with Cdc42, thereby limiting DOCK8 GEF activity; chemokine signaling through PKCα phosphorylates DOCK8 at three serine sites to release it from LRCH1 and permit its translocation to the leading edge, and Lrch1-deficient mice develop more severe EAE while Lrch1 transgenics are protected [PMID:28028151]. LRCH1 also dampens lymphocyte activation by binding the transmembrane adapter LAT, reducing LAT phosphorylation and its association with GRB2 and promoting LAT endocytosis, which suppresses signalosome assembly and CD8+ T cell proliferation and cytotoxicity; its loss enhances anti-viral, anti-bacterial, and anti-tumor responses and improves human CAR T cell migration and proliferation [PMID:32727906]. A parallel inhibitory role in NK cells operates through attenuation of Src and Lck kinase activation, limiting cytokine and granzyme B output and tumor cytotoxicity [PMID:32173150]. Beyond lymphoid cells, LRCH1 restrains microglia-mediated neuroinflammation by limiting p38 MAPK and Erk1/2 activation and pro-inflammatory polarization [PMID:32631435]. The structural basis of LRCH1's adaptor interactions has not been characterized in the available corpus.","teleology":[{"year":2017,"claim":"Established LRCH1's first molecular mechanism: how a negative regulator could couple chemokine sensing to control of Rho-family GTPase-driven T cell migration.","evidence":"Two-hybrid screen, reciprocal co-IP, DOCK8 serine-site mutagenesis, and Lrch1 KO/transgenic mouse EAE models with migration assays","pmids":["28028151"],"confidence":"High","gaps":["No structural model of the LRCH1–DOCK8 interface","Whether LRCH1 regulates GEFs other than DOCK8 not addressed","The PKCα substrate relationship within this module not directly resolved for LRCH1 itself"]},{"year":2020,"claim":"Identified a distinct LRCH1 mechanism in effector lymphocytes—direct control of the LAT signalosome—extending its role from migration to antigen-driven activation and cytotoxicity.","evidence":"Direct LRCH1–LAT co-IP, phosphorylation and endocytosis assays, Lrch1-/- infection and B16 tumor models, and LRCH1 KO in human CAR T cells","pmids":["32727906"],"confidence":"High","gaps":["Mechanism by which LRCH1 promotes LAT endocytosis unresolved","Relationship between the LAT and DOCK8 functions of LRCH1 not integrated","No structural basis for LRCH1–LAT binding"]},{"year":2020,"claim":"Showed LRCH1's suppressive function generalizes to NK cells via attenuation of proximal Src/Lck kinase signaling rather than receptor expression.","evidence":"CRISPR-Cas9 LRCH1 KO in NK-92 and primary human NK cells with cytokine/granzyme B and Src/Lck activation readouts plus in vivo killing assays","pmids":["32173150"],"confidence":"Medium","gaps":["Direct LRCH1 binding partner in NK cells not identified","Link between Src/Lck attenuation and any LAT- or DOCK8-dependent mechanism not established","Single-lab study"]},{"year":2020,"claim":"Placed LRCH1 upstream of PKCα in CD4+ T cell chemotaxis, reinforcing its selective control of migration without affecting differentiation.","evidence":"Lentiviral overexpression/knockdown in human CD4+ T cells with Transwell chemotaxis toward CXCL12 and differentiation/cytokine profiling","pmids":["32210709"],"confidence":"Medium","gaps":["Molecular target linking LRCH1 to PKCα in CD4+ cells not defined","Whether the DOCK8 module operates in CD4+ cells not tested","Single-lab study"]},{"year":2020,"claim":"Extended LRCH1's anti-inflammatory function beyond lymphocytes to innate myeloid cells of the CNS.","evidence":"Lentiviral LRCH1 knockdown in primary microglia with cytokine, polarization, and MAPK phosphorylation readouts plus adoptive transfer into a rat SCI model","pmids":["32631435"],"confidence":"Medium","gaps":["Direct molecular target of LRCH1 in microglia not identified","Mechanism linking LRCH1 to p38/Erk1/2 unresolved","Knockdown rather than clean knockout"]},{"year":null,"claim":"Whether the migration (DOCK8), activation (LAT), kinase (Src/Lck), and MAPK functions of LRCH1 reflect one unifying biochemical activity or distinct context-specific adaptor roles remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural or domain-level mechanism unifying the partners","No biochemical activity assigned to the LRR/CH domains","Cross-talk among the partners untested"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,3]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0,1,3]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,3,4]}],"complexes":[],"partners":["DOCK8","LAT"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9Y2L9","full_name":"Leucine-rich repeat and calponin homology domain-containing protein 1","aliases":["Calponin homology domain-containing protein 1","Neuronal protein 81","NP81"],"length_aa":728,"mass_kda":80.9,"function":"Acts as a negative regulator of GTPase CDC42 by sequestering CDC42-guanine exchange factor DOCK8. Probably by preventing CDC42 activation, negatively regulates CD4(+) T-cell migration","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q9Y2L9/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/LRCH1","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"DOCK7","stoichiometry":10.0},{"gene":"CALD1","stoichiometry":0.2},{"gene":"CALM3","stoichiometry":0.2},{"gene":"MIF","stoichiometry":0.2},{"gene":"MYO6","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/LRCH1","total_profiled":1310},"omim":[{"mim_id":"610368","title":"LEUCINE-RICH REPEATS- AND CALPONIN HOMOLOGY DOMAIN-CONTAINING PROTEIN 1; LRCH1","url":"https://www.omim.org/entry/610368"},{"mim_id":"165720","title":"OSTEOARTHRITIS SUSCEPTIBILITY 1; OS1","url":"https://www.omim.org/entry/165720"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Actin filaments","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"},{"location":"Nucleoli","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/LRCH1"},"hgnc":{"alias_symbol":["KIAA1016"],"prev_symbol":["CHDC1"]},"alphafold":{"accession":"Q9Y2L9","domains":[{"cath_id":"3.80.10.10","chopping":"64-88_95-283","consensus_level":"medium","plddt":93.8675,"start":64,"end":283},{"cath_id":"1.10.418.10","chopping":"579-690","consensus_level":"high","plddt":87.4999,"start":579,"end":690}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y2L9","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y2L9-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y2L9-F1-predicted_aligned_error_v6.png","plddt_mean":62.78},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=LRCH1","jax_strain_url":"https://www.jax.org/strain/search?query=LRCH1"},"sequence":{"accession":"Q9Y2L9","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9Y2L9.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9Y2L9/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y2L9"}},"corpus_meta":[{"pmid":"17762607","id":"PMC_17762607","title":"New gene associations in osteoarthritis: what do they provide, and where are we going?","date":"2007","source":"Current opinion in rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/17762607","citation_count":50,"is_preprint":false},{"pmid":"16447229","id":"PMC_16447229","title":"Association between a variation in LRCH1 and knee osteoarthritis: a genome-wide single-nucleotide polymorphism association study using DNA pooling.","date":"2006","source":"Arthritis and rheumatism","url":"https://pubmed.ncbi.nlm.nih.gov/16447229","citation_count":49,"is_preprint":false},{"pmid":"28028151","id":"PMC_28028151","title":"LRCH1 interferes with DOCK8-Cdc42-induced T cell migration and ameliorates experimental autoimmune encephalomyelitis.","date":"2017","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/28028151","citation_count":40,"is_preprint":false},{"pmid":"24850809","id":"PMC_24850809","title":"Genetic determinants of P wave duration and PR segment.","date":"2014","source":"Circulation. Cardiovascular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/24850809","citation_count":39,"is_preprint":false},{"pmid":"24478024","id":"PMC_24478024","title":"Gene-dosage dependent overexpression at the 13q amplicon identifies DIS3 as candidate oncogene in colorectal cancer progression.","date":"2014","source":"Genes, chromosomes & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/24478024","citation_count":32,"is_preprint":false},{"pmid":"34727735","id":"PMC_34727735","title":"Whole-Genome Sequencing Association Analyses of Stroke and Its Subtypes in Ancestrally Diverse Populations From Trans-Omics for Precision Medicine Project.","date":"2021","source":"Stroke","url":"https://pubmed.ncbi.nlm.nih.gov/34727735","citation_count":26,"is_preprint":false},{"pmid":"27974301","id":"PMC_27974301","title":"Radiographic endophenotyping in hip osteoarthritis improves the precision of genetic association analysis.","date":"2016","source":"Annals of the rheumatic diseases","url":"https://pubmed.ncbi.nlm.nih.gov/27974301","citation_count":24,"is_preprint":false},{"pmid":"32631435","id":"PMC_32631435","title":"Inhibition of leucine-rich repeats and calponin homology domain containing 1 accelerates microglia-mediated neuroinflammation in a rat traumatic spinal cord injury model.","date":"2020","source":"Journal of neuroinflammation","url":"https://pubmed.ncbi.nlm.nih.gov/32631435","citation_count":19,"is_preprint":false},{"pmid":"16891653","id":"PMC_16891653","title":"Genetic association analysis of LRCH1 as an osteoarthritis susceptibility locus.","date":"2006","source":"Rheumatology (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/16891653","citation_count":18,"is_preprint":false},{"pmid":"18049793","id":"PMC_18049793","title":"Lack of association of single nucleotide polymorphism in LRCH1 with knee osteoarthritis susceptibility.","date":"2007","source":"Journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/18049793","citation_count":15,"is_preprint":false},{"pmid":"20237151","id":"PMC_20237151","title":"Field synopsis and synthesis of genetic association studies in osteoarthritis: the CUMAGAS-OSTEO information system.","date":"2010","source":"American journal of epidemiology","url":"https://pubmed.ncbi.nlm.nih.gov/20237151","citation_count":13,"is_preprint":false},{"pmid":"37365285","id":"PMC_37365285","title":"Probing the diabetes and colorectal cancer relationship using gene - environment interaction analyses.","date":"2023","source":"British journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/37365285","citation_count":11,"is_preprint":false},{"pmid":"29936662","id":"PMC_29936662","title":"Progression Rate Associated Peripheral Blood Biomarkers of Parkinson's Disease.","date":"2018","source":"Journal of molecular neuroscience : MN","url":"https://pubmed.ncbi.nlm.nih.gov/29936662","citation_count":11,"is_preprint":false},{"pmid":"32727906","id":"PMC_32727906","title":"LRCH1 deficiency enhances LAT signalosome formation and CD8+ T cell responses against tumors and pathogens.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32727906","citation_count":10,"is_preprint":false},{"pmid":"32210709","id":"PMC_32210709","title":"LRCH1 suppresses migration of CD4+ T cells and refers to disease activity in ulcerative colitis.","date":"2020","source":"International journal of medical sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32210709","citation_count":9,"is_preprint":false},{"pmid":"39730871","id":"PMC_39730871","title":"Identification of shared genetic etiology of cardiovascular and cerebrovascular diseases through common cardiometabolic risk factors.","date":"2024","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/39730871","citation_count":8,"is_preprint":false},{"pmid":"31842790","id":"PMC_31842790","title":"LRCH1 polymorphisms linked to delayed encephalopathy after acute carbon monoxide poisoning identified by GWAS analysis followed by Sequenom MassARRAY® validation.","date":"2019","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/31842790","citation_count":5,"is_preprint":false},{"pmid":"32173150","id":"PMC_32173150","title":"Leucine rich repeats and calponin homology domain containing 1 inhibits NK-92 cell cytotoxicity through attenuating Src signaling.","date":"2020","source":"Immunobiology","url":"https://pubmed.ncbi.nlm.nih.gov/32173150","citation_count":2,"is_preprint":false},{"pmid":"42003665","id":"PMC_42003665","title":"Integration of Genome-Wide Association Studies With Single-Cell and Bulk Expression Quantitative Trait Locus to Identify Stroke Susceptibility Genes.","date":"2026","source":"Journal of the American Heart Association","url":"https://pubmed.ncbi.nlm.nih.gov/42003665","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":12179,"output_tokens":1835,"usd":0.032031,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8704,"output_tokens":2387,"usd":0.051597,"stage2_stop_reason":"end_turn"},"total_usd":0.083628,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2017,\n      \"finding\": \"LRCH1 competes with Cdc42 for binding to DOCK8, thereby restraining DOCK8's guanine-nucleotide exchange factor (GEF) activity toward Cdc42 and inhibiting T cell migration. In response to chemokine stimulation, PKCα phosphorylates DOCK8 at three serine sites, promoting DOCK8 dissociation from LRCH1 and translocation to the leading edge. Point mutations at the DOCK8 serine sites block chemokine- and PKCα-induced T cell migration. Lrch1-deficient mice display more severe experimental autoimmune encephalomyelitis (EAE), while Lrch1 transgenic mice are protected, establishing LRCH1 as a negative regulator of the PKCα–DOCK8–Cdc42 migration module.\",\n      \"method\": \"Two-hybrid screening, co-immunoprecipitation, point mutagenesis of DOCK8 serine sites, Lrch1 transgenic and knockout mouse EAE model, directional migration assays\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal binding assays, mutagenesis of functional sites, and in vivo genetic models (KO and transgenic) with defined phenotypic readout, all in one study\",\n      \"pmids\": [\"28028151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LRCH1 directly binds the transmembrane adapter protein LAT, reduces LAT phosphorylation, reduces LAT interaction with GRB2, and promotes LAT endocytosis, thereby dampening LAT signalosome formation and CD8+ T cell activation. Lrch1-knockout mice show enhanced CD8+ T cell proliferation and cytotoxicity against influenza virus, Listeria, and B16 tumor cells. Knockout of LRCH1 in human CAR T cells improved their migration and proliferation in vitro.\",\n      \"method\": \"Co-immunoprecipitation (direct LRCH1–LAT binding), phosphorylation assays, endocytosis assays, Lrch1-/- mouse infection and tumor models, adoptive transfer of Lrch1-/- CD8+ CTLs, LRCH1 KO in human CAR T cells\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct binding assay, multiple functional readouts (phosphorylation, endocytosis, in vivo tumor and infection models), genetic KO with defined phenotypes\",\n      \"pmids\": [\"32727906\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LRCH1 knockdown in microglia increased production of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) after LPS/ATP priming, promoted polarization toward iNOS-expressing (pro-inflammatory) microglia, enhanced microglia-mediated N27 neuron death, and increased activation of p38 MAPK and Erk1/2 signaling. Adoptive injection of LRCH1-knockdown microglia into rat spinal cords worsened post-SCI inflammation, tissue damage, and locomotor function, establishing LRCH1 as a negative regulator of microglia-mediated neuroinflammation via p38 MAPK and Erk1/2 pathways.\",\n      \"method\": \"Lentivirus-mediated LRCH1 knockdown in primary microglia, cytokine ELISA/qPCR, flow cytometry for polarization markers, p38 MAPK and Erk1/2 phosphorylation assays, adoptive transfer into rat SCI model with behavioral and histological readouts\",\n      \"journal\": \"Journal of neuroinflammation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro knockdown with pathway readouts and in vivo adoptive transfer model, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"32631435\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LRCH1 inhibits NK-92 cell cytotoxicity against tumor cells. LRCH1 knockout (CRISPR-Cas9) did not affect basal NK-92 cell survival or natural cytotoxicity receptor expression, but upon tumor cell contact increased production of IFN-γ, TNF-α, IL-2, and granzyme B, and enhanced Src and Lck kinase activation. Primary human NK cells showed similar cytokine increases upon LRCH1 knockout, identifying Src/Lck signaling as the pathway negatively regulated by LRCH1 in NK cells.\",\n      \"method\": \"CRISPR-Cas9 knockout of LRCH1 in NK-92 cells and primary human NK cells, cytokine/granzyme B measurement, Src and Lck kinase activation assays, in vivo tumor killing assay\",\n      \"journal\": \"Immunobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean CRISPR KO with defined signaling (Src/Lck) and functional (cytotoxicity) readouts, single lab\",\n      \"pmids\": [\"32173150\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LRCH1 inhibits the migratory capacity of CD4+ T cells toward CXCL12. Lentiviral overexpression or knockdown of LRCH1 did not affect CD4+ T cell differentiation or related cytokine expression, but modulated chemotaxis in a PKCα-dependent manner, placing LRCH1 upstream of PKCα in CD4+ T cell migration.\",\n      \"method\": \"Lentiviral LRCH1 overexpression and knockdown in peripheral blood CD4+ T cells, Transwell chemotaxis assay toward CXCL12, flow cytometry for differentiation markers, cytokine ELISA/qPCR\",\n      \"journal\": \"International journal of medical sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — clean gain- and loss-of-function with defined migratory phenotype and PKCα pathway placement, single lab\",\n      \"pmids\": [\"32210709\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"LRCH1 is a multifunctional negative regulator of immune cell migration and cytotoxicity: it restrains T cell migration by competing with Cdc42 for DOCK8 binding (disrupted by PKCα-mediated DOCK8 phosphorylation), suppresses CD8+ T cell and NK cell activation by binding LAT and attenuating Src/Lck signaling, inhibits CD4+ T cell chemotaxis via PKCα, and dampens microglial neuroinflammation through p38 MAPK and Erk1/2 pathways.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"LRCH1 is a cytoplasmic adaptor protein that acts as a negative regulator of immune cell migration and effector activation across multiple cell types [#0, #1]. In T cells it restrains directional migration by sequestering the guanine-nucleotide exchange factor DOCK8 and competing with Cdc42, thereby limiting DOCK8 GEF activity; chemokine signaling through PKCα phosphorylates DOCK8 at three serine sites to release it from LRCH1 and permit its translocation to the leading edge, and Lrch1-deficient mice develop more severe EAE while Lrch1 transgenics are protected [#0]. LRCH1 also dampens lymphocyte activation by binding the transmembrane adapter LAT, reducing LAT phosphorylation and its association with GRB2 and promoting LAT endocytosis, which suppresses signalosome assembly and CD8+ T cell proliferation and cytotoxicity; its loss enhances anti-viral, anti-bacterial, and anti-tumor responses and improves human CAR T cell migration and proliferation [#1]. A parallel inhibitory role in NK cells operates through attenuation of Src and Lck kinase activation, limiting cytokine and granzyme B output and tumor cytotoxicity [#3]. Beyond lymphoid cells, LRCH1 restrains microglia-mediated neuroinflammation by limiting p38 MAPK and Erk1/2 activation and pro-inflammatory polarization [#2]. The structural basis of LRCH1's adaptor interactions has not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2017,\n      \"claim\": \"Established LRCH1's first molecular mechanism: how a negative regulator could couple chemokine sensing to control of Rho-family GTPase-driven T cell migration.\",\n      \"evidence\": \"Two-hybrid screen, reciprocal co-IP, DOCK8 serine-site mutagenesis, and Lrch1 KO/transgenic mouse EAE models with migration assays\",\n      \"pmids\": [\"28028151\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No structural model of the LRCH1\\u2013DOCK8 interface\", \"Whether LRCH1 regulates GEFs other than DOCK8 not addressed\", \"The PKC\\u03b1 substrate relationship within this module not directly resolved for LRCH1 itself\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified a distinct LRCH1 mechanism in effector lymphocytes\\u2014direct control of the LAT signalosome\\u2014extending its role from migration to antigen-driven activation and cytotoxicity.\",\n      \"evidence\": \"Direct LRCH1\\u2013LAT co-IP, phosphorylation and endocytosis assays, Lrch1-/- infection and B16 tumor models, and LRCH1 KO in human CAR T cells\",\n      \"pmids\": [\"32727906\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which LRCH1 promotes LAT endocytosis unresolved\", \"Relationship between the LAT and DOCK8 functions of LRCH1 not integrated\", \"No structural basis for LRCH1\\u2013LAT binding\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed LRCH1's suppressive function generalizes to NK cells via attenuation of proximal Src/Lck kinase signaling rather than receptor expression.\",\n      \"evidence\": \"CRISPR-Cas9 LRCH1 KO in NK-92 and primary human NK cells with cytokine/granzyme B and Src/Lck activation readouts plus in vivo killing assays\",\n      \"pmids\": [\"32173150\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct LRCH1 binding partner in NK cells not identified\", \"Link between Src/Lck attenuation and any LAT- or DOCK8-dependent mechanism not established\", \"Single-lab study\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Placed LRCH1 upstream of PKC\\u03b1 in CD4+ T cell chemotaxis, reinforcing its selective control of migration without affecting differentiation.\",\n      \"evidence\": \"Lentiviral overexpression/knockdown in human CD4+ T cells with Transwell chemotaxis toward CXCL12 and differentiation/cytokine profiling\",\n      \"pmids\": [\"32210709\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular target linking LRCH1 to PKC\\u03b1 in CD4+ cells not defined\", \"Whether the DOCK8 module operates in CD4+ cells not tested\", \"Single-lab study\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Extended LRCH1's anti-inflammatory function beyond lymphocytes to innate myeloid cells of the CNS.\",\n      \"evidence\": \"Lentiviral LRCH1 knockdown in primary microglia with cytokine, polarization, and MAPK phosphorylation readouts plus adoptive transfer into a rat SCI model\",\n      \"pmids\": [\"32631435\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular target of LRCH1 in microglia not identified\", \"Mechanism linking LRCH1 to p38/Erk1/2 unresolved\", \"Knockdown rather than clean knockout\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether the migration (DOCK8), activation (LAT), kinase (Src/Lck), and MAPK functions of LRCH1 reflect one unifying biochemical activity or distinct context-specific adaptor roles remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural or domain-level mechanism unifying the partners\", \"No biochemical activity assigned to the LRR/CH domains\", \"Cross-talk among the partners untested\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 3, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"DOCK8\", \"LAT\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}