{"gene":"WDFY4","run_date":"2026-04-28T23:00:23","timeline":{"discoveries":[{"year":2018,"finding":"WDFY4, a BEACH domain-containing protein, is essential for cross-presentation of cell-associated antigens by Batf3-dependent cDC1s (CD8α+/XCR1+ classical dendritic cells) to CD8+ T cells in mice, identified via a functional CRISPR screen. WDFY4 knockout mice fail to prime virus-specific CD8+ T cells in vivo and cannot induce tumor rejection, but retain normal cDC1 populations, MHC-II presentation, and IL-12 production, demonstrating a specific role in the cross-presentation pathway rather than cDC1 development.","method":"CRISPR screen, Wdfy4-/- mouse knockout, in vivo CD8+ T cell priming assays, tumor rejection assays, flow cytometry, Toxoplasma infection model","journal":"Science (New York, N.Y.)","confidence":"High","confidence_rationale":"Tier 2 — clean KO with multiple orthogonal functional readouts, replicated across viral and tumor antigen contexts","pmids":["30409884"],"is_preprint":false},{"year":2025,"finding":"WDFY4-dependent cross-presentation is not exclusive to cDC1s; cDC2s also use a WDFY4-dependent pathway to cross-present immune complex antigens to CD8+ T cells in vivo, enabling tumor rejection even in the absence of cDC1s. Monocyte-derived DCs do not participate in this WDFY4-dependent cross-presentation.","method":"Genetic mouse models (cDC1-deficient, cDC2-deficient, Wdfy4-/- mice), immune complex vaccination, in vivo CD8+ T cell priming, tumor rejection assays","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic models with functional in vivo readouts","pmids":["39918736"],"is_preprint":false},{"year":2018,"finding":"Both full-length WDFY4 and a truncated isoform (tr-WDFY4) physically interact with pattern recognition receptors TLR3, TLR4, TLR9, and MDA5, and augment NF-κB activation downstream of these receptors. The truncated isoform (encoded by the CADM-risk allele) also enhances MDA5-induced apoptosis more than full-length WDFY4.","method":"Co-immunoprecipitation (interaction with TLRs and MDA5), NF-κB reporter assays, apoptosis assays, trans-eQTL analysis","journal":"Annals of the rheumatic diseases","confidence":"Medium","confidence_rationale":"Tier 2/3 — Co-IP and functional reporter assays in a single study","pmids":["29331962"],"is_preprint":false},{"year":2018,"finding":"In B cells, WDFY4 facilitates noncanonical autophagic activity. Loss of WDFY4 in B cells (conditional knockout) increases LC3 lipidation independently of p62 and Beclin1 (canonical autophagy markers), and leads to defects in B cell development (pro- to pre-B cell transition), reduced peripheral B cell numbers, impaired antibody responses, and amelioration of SLE phenotypes including autoantibody production and glomerulonephritis.","method":"B cell-conditional Wdfy4 knockout mice, LC3 lipidation assay, flow cytometry of B cell subsets, pristane-induced SLE model, antibody response assays","journal":"Journal of immunology (Baltimore, Md. : 1950)","confidence":"Medium","confidence_rationale":"Tier 2 — conditional KO with multiple cellular and in vivo phenotypic readouts, single lab","pmids":["30257884"],"is_preprint":false},{"year":2023,"finding":"In NOD mice, WDFY4 deficiency (via CRISPR/Cas9) abolishes cross-presentation of cell-associated antigens by cDC1s, preventing priming of autoreactive CD8+ T cells, and as a consequence blocks recruitment of autoreactive CD4+ T cells into islets and prevents autoimmune diabetes, while MHC-II antigen presentation and CD4+ T cell activation in lymph nodes remain intact.","method":"CRISPR/Cas9 Wdfy4-/- NOD mice, cross-presentation assays, diabetes incidence monitoring, insulitis histology, T cell priming assays","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — clean KO in disease model with multiple orthogonal readouts demonstrating pathway epistasis","pmids":["36940342"],"is_preprint":false},{"year":2021,"finding":"Selective deficiency of WDFY4 in T cells leads to reduced CD8+ T cell numbers in the periphery, enhanced CD8+ T cell apoptosis, elevated intracellular reactive oxygen species (ROS) with upregulation of Nox2, and activation of the p53 pathway with inhibition of the ERK pathway. This results in impaired antitumor CD8+ T cell responses.","method":"T cell-conditional Wdfy4 knockout mice, flow cytometry, ROS measurement, apoptosis assays, p53/ERK pathway analysis, transplantable tumor model","journal":"Molecular immunology","confidence":"Medium","confidence_rationale":"Tier 2 — conditional KO with defined mechanistic pathway (p53/ERK/ROS/Nox2), single lab","pmids":["34482201"],"is_preprint":false},{"year":2021,"finding":"WDFY4 deficiency in mice promotes Th2 cell differentiation and Th2 cytokine production in vitro and in vivo, and exacerbates ovalbumin-induced asthma with enhanced inflammatory cell infiltration, goblet cell hyperplasia, mucus production, and collagen deposition.","method":"Wdfy4-/- mouse model, in vitro Th2 differentiation from naïve CD4+ T cells, OVA-induced asthma model, cytokine measurement, histology","journal":"International archives of allergy and immunology","confidence":"Medium","confidence_rationale":"Tier 2 — KO with in vitro and in vivo phenotypic readouts, single lab","pmids":["34425575"],"is_preprint":false},{"year":2025,"finding":"WDFY4 interacts with lysosomal transmembrane protein LAPTM5, validated by co-immunoprecipitation and immunofluorescence co-localization, and this interaction promotes ferroptosis in endothelial cells. Mechanistically, WDFY4 promotes LAPTM5 expression, which suppresses the CDC42/mTOR/4EBP1/SLC7A11 pathway to enhance ferroptosis. Endothelial-specific WDFY4 knockout reduces atherosclerotic plaque formation in ApoE-/- mice.","method":"Co-immunoprecipitation, immunofluorescence co-localization, WDFY4 knockdown/knockout in vitro and in vivo (endothelium-specific transgenic mice), ApoE-/- HFD atherosclerosis model, pathway inhibitor rescue experiments","journal":"Journal of cellular and molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2/3 — Co-IP plus in vivo genetic model with rescue experiments, single lab","pmids":["40755163"],"is_preprint":false},{"year":2012,"finding":"The transcription factor YY1 (Yinyang1) binds to an intronic SLE-associated variant site (rs877819) in WDFY4; the risk allele (A) reduces YY1 binding affinity, resulting in lower transcriptional activity of WDFY4. WDFY4 is significantly downregulated in SLE patients carrying this allele.","method":"Electrophoretic mobility shift assay (EMSA), supershift assay, dual-luciferase reporter assay, YY1 siRNA knockdown and overexpression, chromatin immunoprecipitation (ChIP), allelic expression analysis","journal":"Genes and immunity","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal methods (EMSA, ChIP, reporter assay, KD/OE) in single study","pmids":["22972472"],"is_preprint":false}],"current_model":"WDFY4 is a BEACH domain-containing protein that functions as an essential mediator of cross-presentation of exogenous/cell-associated antigens by conventional dendritic cells (both cDC1 and cDC2) to prime CD8+ T cells, while also regulating B cell noncanonical autophagy and development, CD8+ T cell survival via ROS/p53/ERK pathways, Th2 cell differentiation, and innate immune signaling by interacting with TLRs and MDA5 to augment NF-κB activation; its expression is regulated transcriptionally by YY1 binding to a disease-associated intronic variant."},"narrative":{"teleology":[{"year":2012,"claim":"Establishing how a disease-associated variant regulates WDFY4 expression resolved the question of whether SLE risk SNPs in WDFY4 are functionally consequential at the transcriptional level.","evidence":"EMSA, ChIP, luciferase reporter assays, and YY1 knockdown/overexpression in human cells showing YY1 binding at rs877819 controls WDFY4 transcription","pmids":["22972472"],"confidence":"Medium","gaps":["Which immune cell types are most affected by reduced WDFY4 transcription in vivo remains undefined","Whether other transcription factors co-regulate WDFY4 at this locus is untested"]},{"year":2018,"claim":"Identification of WDFY4 as an essential, specific mediator of cross-presentation in cDC1s established its core molecular function — enabling MHC-I loading of exogenous antigens without affecting MHC-II presentation, cDC1 development, or IL-12 production.","evidence":"CRISPR screen in cDC1 line and Wdfy4-/- mice with viral, parasitic, and tumor antigen challenge models","pmids":["30409884"],"confidence":"High","gaps":["The precise molecular step in the cross-presentation pathway where WDFY4 acts (e.g., phagosome-to-cytosol export, proteasomal access, peptide loading) is unknown","Whether WDFY4 functions as a scaffold, transporter, or membrane remodeler has not been determined"]},{"year":2018,"claim":"Demonstrating that WDFY4 physically interacts with TLR3/4/9 and MDA5 and augments NF-κB activation revealed a second functional axis beyond cross-presentation — amplification of innate immune signaling.","evidence":"Co-immunoprecipitation with TLRs and MDA5, NF-κB luciferase reporter assays, and apoptosis assays showing enhanced MDA5-induced apoptosis by truncated WDFY4","pmids":["29331962"],"confidence":"Medium","gaps":["Interactions validated by Co-IP only without reciprocal pull-down or endogenous IP in primary cells","Mechanism by which WDFY4 augments NF-κB (scaffolding vs. signalosome assembly) is not defined","Relevance of truncated isoform in physiological settings beyond overexpression systems is unclear"]},{"year":2018,"claim":"Conditional deletion in B cells revealed that WDFY4 restrains noncanonical autophagy (LC3 lipidation independent of p62/Beclin1) and is required for normal B cell development and humoral immunity, connecting it to SLE pathogenesis.","evidence":"B cell-conditional Wdfy4 knockout mice with LC3 lipidation assays, B cell subset flow cytometry, pristane-induced lupus model","pmids":["30257884"],"confidence":"Medium","gaps":["Molecular targets of WDFY4-regulated noncanonical autophagy in B cells are uncharacterized","Whether the autophagy phenotype in B cells relates mechanistically to the cross-presentation function in DCs is unknown"]},{"year":2021,"claim":"T cell-conditional knockout established that WDFY4 maintains CD8+ T cell survival by suppressing ROS/Nox2 accumulation and p53-mediated apoptosis while sustaining ERK signaling, broadening its function beyond antigen-presenting cells.","evidence":"T cell-conditional Wdfy4 KO mice with ROS quantification, apoptosis assays, p53/ERK pathway analysis, and transplantable tumor models","pmids":["34482201"],"confidence":"Medium","gaps":["Direct molecular link between WDFY4 and Nox2/ROS regulation is not established","Single-lab finding; independent replication lacking"]},{"year":2021,"claim":"Showing that WDFY4 loss promotes Th2 differentiation and exacerbates allergic asthma extended its immune-regulatory role to CD4+ T helper cell polarization.","evidence":"Wdfy4-/- mice with in vitro Th2 differentiation and OVA-induced asthma model","pmids":["34425575"],"confidence":"Medium","gaps":["Mechanism by which WDFY4 suppresses Th2 polarization (transcription factor regulation, cytokine signaling) is not defined","Single-lab study without independent confirmation"]},{"year":2023,"claim":"Demonstrating that WDFY4 deficiency in NOD mice prevents autoimmune diabetes by abolishing cross-presentation of islet antigens proved that WDFY4-dependent cross-presentation is the critical gateway for autoreactive CD8+ T cell priming in organ-specific autoimmunity.","evidence":"CRISPR/Cas9 Wdfy4-/- NOD mice with diabetes incidence monitoring, insulitis histology, and cross-presentation/T cell priming assays","pmids":["36940342"],"confidence":"High","gaps":["Whether therapeutic targeting of WDFY4 can reverse established autoimmunity is untested","The specific islet antigens cross-presented via WDFY4 are not identified"]},{"year":2025,"claim":"Extending WDFY4-dependent cross-presentation to cDC2s demonstrated that this function is not cDC1-exclusive, fundamentally revising the model of which DC subsets require WDFY4 for CD8+ T cell priming.","evidence":"cDC1-deficient, cDC2-deficient, and Wdfy4-/- genetic mouse models with immune complex vaccination and tumor rejection assays","pmids":["39918736"],"confidence":"High","gaps":["Whether WDFY4 operates through the same molecular mechanism in cDC2s as in cDC1s is not established","The antigen forms (particulate vs. soluble vs. immune complex) that differentially engage WDFY4 in each DC subset remain unclear"]},{"year":2025,"claim":"Discovery of a WDFY4–LAPTM5 interaction that promotes endothelial ferroptosis via suppression of the CDC42/mTOR/4EBP1/SLC7A11 axis revealed a non-immune function in vascular biology and atherosclerosis.","evidence":"Co-IP, co-localization, endothelium-specific WDFY4 knockout in ApoE-/- mice on HFD with pathway inhibitor rescue","pmids":["40755163"],"confidence":"Medium","gaps":["Single-lab finding; endothelial ferroptosis link not independently replicated","Whether the LAPTM5 interaction is relevant to WDFY4's immune cell functions is unknown","Structural basis for WDFY4–LAPTM5 interaction not determined"]},{"year":null,"claim":"The precise molecular step at which WDFY4 acts in the cross-presentation pathway — whether it facilitates antigen escape from endosomes, phagosomal membrane integrity, peptide–MHC-I loading, or vesicular trafficking — remains the central unresolved question.","evidence":"","pmids":[],"confidence":"High","gaps":["No structural model of WDFY4 or its BEACH domain in the context of cross-presentation machinery exists","Direct substrates or cargo of WDFY4 in DCs have not been identified","Relationship between WDFY4's roles in autophagy regulation, innate signaling, and cross-presentation is mechanistically unintegrated"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2]}],"localization":[{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[7]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[2]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0,1,2,3,4,5,6]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[3]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[5,7]}],"complexes":[],"partners":["TLR3","TLR4","TLR9","MDA5","LAPTM5"],"other_free_text":[]},"mechanistic_narrative":"WDFY4 is a BEACH domain-containing protein that serves as a central regulator of antigen cross-presentation and immune cell homeostasis. It is essential for cross-presentation of cell-associated and immune-complex antigens by both cDC1 and cDC2 dendritic cell subsets to CD8+ T cells, enabling antiviral immunity and tumor rejection without affecting MHC-II presentation or dendritic cell development [PMID:30409884, PMID:39918736, PMID:36940342]. Beyond dendritic cells, WDFY4 regulates B cell noncanonical autophagy and development, CD8+ T cell survival through a ROS/p53/ERK axis, Th2 differentiation, and innate NF-κB signaling downstream of TLR3/4/9 and MDA5 [PMID:30257884, PMID:34482201, PMID:34425575, PMID:29331962]. WDFY4 expression is transcriptionally controlled by YY1 binding at an SLE-associated intronic variant, linking reduced WDFY4 levels to systemic lupus erythematosus susceptibility [PMID:22972472]."},"prefetch_data":{"uniprot":{"accession":"Q6ZS81","full_name":"WD repeat- and FYVE domain-containing protein 4","aliases":[],"length_aa":3184,"mass_kda":353.6,"function":"Plays a critical role in the regulation of cDC1-mediated cross-presentation of viral and tumor antigens in dendritic cells. Mechanistically, acts near the plasma membrane and interacts with endosomal membranes to promote endosomal-to-cytosol antigen trafficking. Also plays a role in B-cell survival through regulation of autophagy","subcellular_location":"Early endosome; Endoplasmic reticulum","url":"https://www.uniprot.org/uniprotkb/Q6ZS81/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/WDFY4","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/WDFY4","total_profiled":1310},"omim":[{"mim_id":"613316","title":"WD REPEAT- AND FYVE DOMAIN-CONTAINING PROTEIN 4; WDFY4","url":"https://www.omim.org/entry/613316"},{"mim_id":"606493","title":"EXOSOME COMPONENT 1; EXOSC1","url":"https://www.omim.org/entry/606493"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"bone marrow","ntpm":11.0},{"tissue":"lymphoid tissue","ntpm":26.6}],"url":"https://www.proteinatlas.org/search/WDFY4"},"hgnc":{"alias_symbol":["KIAA1607","Em:AC060234.3","FLJ45748"],"prev_symbol":["C10orf64"]},"alphafold":{"accession":"Q6ZS81","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6ZS81","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6ZS81-3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6ZS81-3-F1-predicted_aligned_error_v6.png","plddt_mean":78.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=WDFY4","jax_strain_url":"https://www.jax.org/strain/search?query=WDFY4"},"sequence":{"accession":"Q6ZS81","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6ZS81.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6ZS81/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6ZS81"}},"corpus_meta":[{"pmid":"20169177","id":"PMC_20169177","title":"Genome-wide association study in Asian populations identifies variants in ETS1 and WDFY4 associated with systemic lupus erythematosus.","date":"2010","source":"PLoS genetics","url":"https://pubmed.ncbi.nlm.nih.gov/20169177","citation_count":343,"is_preprint":false},{"pmid":"30409884","id":"PMC_30409884","title":"WDFY4 is required for cross-presentation in response to viral and tumor antigens.","date":"2018","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/30409884","citation_count":264,"is_preprint":false},{"pmid":"29331962","id":"PMC_29331962","title":"Splicing variant of WDFY4 augments MDA5 signalling and the risk of clinically amyopathic dermatomyositis.","date":"2018","source":"Annals of the rheumatic diseases","url":"https://pubmed.ncbi.nlm.nih.gov/29331962","citation_count":63,"is_preprint":false},{"pmid":"22972472","id":"PMC_22972472","title":"An intronic variant associated with systemic lupus erythematosus changes the binding affinity of Yinyang1 to downregulate WDFY4.","date":"2012","source":"Genes and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/22972472","citation_count":45,"is_preprint":false},{"pmid":"30257884","id":"PMC_30257884","title":"WDFY4 Is Involved in Symptoms of Systemic Lupus Erythematosus by Modulating B Cell Fate via Noncanonical Autophagy.","date":"2018","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/30257884","citation_count":28,"is_preprint":false},{"pmid":"36637178","id":"PMC_36637178","title":"WDFY4 polymorphisms in Chinese patients with anti-MDA5 dermatomyositis is associated with rapid progressive interstitial lung disease.","date":"2023","source":"Rheumatology (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/36637178","citation_count":18,"is_preprint":false},{"pmid":"24549174","id":"PMC_24549174","title":"E26 transformation-specific-1 (ETS1) and WDFY family member 4 (WDFY4) polymorphisms in Chinese patients with rheumatoid arthritis.","date":"2014","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/24549174","citation_count":15,"is_preprint":false},{"pmid":"34482201","id":"PMC_34482201","title":"Deficiency in WDFY4 reduces the number of CD8+ T cells via reactive oxygen species-induced apoptosis.","date":"2021","source":"Molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/34482201","citation_count":14,"is_preprint":false},{"pmid":"39918736","id":"PMC_39918736","title":"Shared pathway of WDFY4-dependent cross-presentation of immune complexes by cDC1 and cDC2.","date":"2025","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/39918736","citation_count":10,"is_preprint":false},{"pmid":"36940342","id":"PMC_36940342","title":"WDFY4 deficiency in NOD mice ameliorates autoimmune diabetes and insulitis.","date":"2023","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/36940342","citation_count":9,"is_preprint":false},{"pmid":"37728413","id":"PMC_37728413","title":"Ferroptosis and WDFY4 as novel targets for immunotherapy of lung adenocarcinoma.","date":"2023","source":"Aging","url":"https://pubmed.ncbi.nlm.nih.gov/37728413","citation_count":8,"is_preprint":false},{"pmid":"38507703","id":"PMC_38507703","title":"The clinical relevance of WDFY4 in autoimmune diseases in diverse ancestral populations.","date":"2024","source":"Rheumatology (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/38507703","citation_count":7,"is_preprint":false},{"pmid":"33189404","id":"PMC_33189404","title":"BVVL/ FL: features caused by SLC52A3 mutations; WDFY4 and TNFSF13B may be novel causative genes.","date":"2020","source":"Neurobiology of aging","url":"https://pubmed.ncbi.nlm.nih.gov/33189404","citation_count":7,"is_preprint":false},{"pmid":"34425575","id":"PMC_34425575","title":"Lack of WDFY4 Aggravates Ovalbumin-Induced Asthma via Enhanced Th2 Cell Differentiation.","date":"2021","source":"International archives of allergy and immunology","url":"https://pubmed.ncbi.nlm.nih.gov/34425575","citation_count":6,"is_preprint":false},{"pmid":"40755163","id":"PMC_40755163","title":"WDFY4 Promotes the Progression of Atherosclerosis by Regulating Ferroptosis Mediated by the LAPTM5/CDC42/mTOR/4EBP1/SLC7A11 Pathway.","date":"2025","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40755163","citation_count":2,"is_preprint":false},{"pmid":"41965494","id":"PMC_41965494","title":"Epigenetic alterations in WDFY4 DNA methylation are linked to immunoinflammatory processes in rheumatoid arthritis: insights from a case-control study.","date":"2026","source":"Clinical rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/41965494","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9848,"output_tokens":2524,"usd":0.033702},"stage2":{"model":"claude-opus-4-6","input_tokens":5830,"output_tokens":2741,"usd":0.146512},"total_usd":0.180214,"stage1_batch_id":"msgbatch_01BparvgRZ9S2LMidvaoo86K","stage2_batch_id":"msgbatch_01NkBfv9SVZWthhS7j6mU6G3","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2018,\n      \"finding\": \"WDFY4, a BEACH domain-containing protein, is essential for cross-presentation of cell-associated antigens by Batf3-dependent cDC1s (CD8α+/XCR1+ classical dendritic cells) to CD8+ T cells in mice, identified via a functional CRISPR screen. WDFY4 knockout mice fail to prime virus-specific CD8+ T cells in vivo and cannot induce tumor rejection, but retain normal cDC1 populations, MHC-II presentation, and IL-12 production, demonstrating a specific role in the cross-presentation pathway rather than cDC1 development.\",\n      \"method\": \"CRISPR screen, Wdfy4-/- mouse knockout, in vivo CD8+ T cell priming assays, tumor rejection assays, flow cytometry, Toxoplasma infection model\",\n      \"journal\": \"Science (New York, N.Y.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with multiple orthogonal functional readouts, replicated across viral and tumor antigen contexts\",\n      \"pmids\": [\"30409884\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"WDFY4-dependent cross-presentation is not exclusive to cDC1s; cDC2s also use a WDFY4-dependent pathway to cross-present immune complex antigens to CD8+ T cells in vivo, enabling tumor rejection even in the absence of cDC1s. Monocyte-derived DCs do not participate in this WDFY4-dependent cross-presentation.\",\n      \"method\": \"Genetic mouse models (cDC1-deficient, cDC2-deficient, Wdfy4-/- mice), immune complex vaccination, in vivo CD8+ T cell priming, tumor rejection assays\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic models with functional in vivo readouts\",\n      \"pmids\": [\"39918736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Both full-length WDFY4 and a truncated isoform (tr-WDFY4) physically interact with pattern recognition receptors TLR3, TLR4, TLR9, and MDA5, and augment NF-κB activation downstream of these receptors. The truncated isoform (encoded by the CADM-risk allele) also enhances MDA5-induced apoptosis more than full-length WDFY4.\",\n      \"method\": \"Co-immunoprecipitation (interaction with TLRs and MDA5), NF-κB reporter assays, apoptosis assays, trans-eQTL analysis\",\n      \"journal\": \"Annals of the rheumatic diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — Co-IP and functional reporter assays in a single study\",\n      \"pmids\": [\"29331962\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In B cells, WDFY4 facilitates noncanonical autophagic activity. Loss of WDFY4 in B cells (conditional knockout) increases LC3 lipidation independently of p62 and Beclin1 (canonical autophagy markers), and leads to defects in B cell development (pro- to pre-B cell transition), reduced peripheral B cell numbers, impaired antibody responses, and amelioration of SLE phenotypes including autoantibody production and glomerulonephritis.\",\n      \"method\": \"B cell-conditional Wdfy4 knockout mice, LC3 lipidation assay, flow cytometry of B cell subsets, pristane-induced SLE model, antibody response assays\",\n      \"journal\": \"Journal of immunology (Baltimore, Md. : 1950)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with multiple cellular and in vivo phenotypic readouts, single lab\",\n      \"pmids\": [\"30257884\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In NOD mice, WDFY4 deficiency (via CRISPR/Cas9) abolishes cross-presentation of cell-associated antigens by cDC1s, preventing priming of autoreactive CD8+ T cells, and as a consequence blocks recruitment of autoreactive CD4+ T cells into islets and prevents autoimmune diabetes, while MHC-II antigen presentation and CD4+ T cell activation in lymph nodes remain intact.\",\n      \"method\": \"CRISPR/Cas9 Wdfy4-/- NOD mice, cross-presentation assays, diabetes incidence monitoring, insulitis histology, T cell priming assays\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO in disease model with multiple orthogonal readouts demonstrating pathway epistasis\",\n      \"pmids\": [\"36940342\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Selective deficiency of WDFY4 in T cells leads to reduced CD8+ T cell numbers in the periphery, enhanced CD8+ T cell apoptosis, elevated intracellular reactive oxygen species (ROS) with upregulation of Nox2, and activation of the p53 pathway with inhibition of the ERK pathway. This results in impaired antitumor CD8+ T cell responses.\",\n      \"method\": \"T cell-conditional Wdfy4 knockout mice, flow cytometry, ROS measurement, apoptosis assays, p53/ERK pathway analysis, transplantable tumor model\",\n      \"journal\": \"Molecular immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with defined mechanistic pathway (p53/ERK/ROS/Nox2), single lab\",\n      \"pmids\": [\"34482201\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"WDFY4 deficiency in mice promotes Th2 cell differentiation and Th2 cytokine production in vitro and in vivo, and exacerbates ovalbumin-induced asthma with enhanced inflammatory cell infiltration, goblet cell hyperplasia, mucus production, and collagen deposition.\",\n      \"method\": \"Wdfy4-/- mouse model, in vitro Th2 differentiation from naïve CD4+ T cells, OVA-induced asthma model, cytokine measurement, histology\",\n      \"journal\": \"International archives of allergy and immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KO with in vitro and in vivo phenotypic readouts, single lab\",\n      \"pmids\": [\"34425575\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"WDFY4 interacts with lysosomal transmembrane protein LAPTM5, validated by co-immunoprecipitation and immunofluorescence co-localization, and this interaction promotes ferroptosis in endothelial cells. Mechanistically, WDFY4 promotes LAPTM5 expression, which suppresses the CDC42/mTOR/4EBP1/SLC7A11 pathway to enhance ferroptosis. Endothelial-specific WDFY4 knockout reduces atherosclerotic plaque formation in ApoE-/- mice.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence co-localization, WDFY4 knockdown/knockout in vitro and in vivo (endothelium-specific transgenic mice), ApoE-/- HFD atherosclerosis model, pathway inhibitor rescue experiments\",\n      \"journal\": \"Journal of cellular and molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — Co-IP plus in vivo genetic model with rescue experiments, single lab\",\n      \"pmids\": [\"40755163\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"The transcription factor YY1 (Yinyang1) binds to an intronic SLE-associated variant site (rs877819) in WDFY4; the risk allele (A) reduces YY1 binding affinity, resulting in lower transcriptional activity of WDFY4. WDFY4 is significantly downregulated in SLE patients carrying this allele.\",\n      \"method\": \"Electrophoretic mobility shift assay (EMSA), supershift assay, dual-luciferase reporter assay, YY1 siRNA knockdown and overexpression, chromatin immunoprecipitation (ChIP), allelic expression analysis\",\n      \"journal\": \"Genes and immunity\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (EMSA, ChIP, reporter assay, KD/OE) in single study\",\n      \"pmids\": [\"22972472\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"WDFY4 is a BEACH domain-containing protein that functions as an essential mediator of cross-presentation of exogenous/cell-associated antigens by conventional dendritic cells (both cDC1 and cDC2) to prime CD8+ T cells, while also regulating B cell noncanonical autophagy and development, CD8+ T cell survival via ROS/p53/ERK pathways, Th2 cell differentiation, and innate immune signaling by interacting with TLRs and MDA5 to augment NF-κB activation; its expression is regulated transcriptionally by YY1 binding to a disease-associated intronic variant.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"WDFY4 is a BEACH domain-containing protein that serves as a central regulator of antigen cross-presentation and immune cell homeostasis. It is essential for cross-presentation of cell-associated and immune-complex antigens by both cDC1 and cDC2 dendritic cell subsets to CD8+ T cells, enabling antiviral immunity and tumor rejection without affecting MHC-II presentation or dendritic cell development [PMID:30409884, PMID:39918736, PMID:36940342]. Beyond dendritic cells, WDFY4 regulates B cell noncanonical autophagy and development, CD8+ T cell survival through a ROS/p53/ERK axis, Th2 differentiation, and innate NF-κB signaling downstream of TLR3/4/9 and MDA5 [PMID:30257884, PMID:34482201, PMID:34425575, PMID:29331962]. WDFY4 expression is transcriptionally controlled by YY1 binding at an SLE-associated intronic variant, linking reduced WDFY4 levels to systemic lupus erythematosus susceptibility [PMID:22972472].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Establishing how a disease-associated variant regulates WDFY4 expression resolved the question of whether SLE risk SNPs in WDFY4 are functionally consequential at the transcriptional level.\",\n      \"evidence\": \"EMSA, ChIP, luciferase reporter assays, and YY1 knockdown/overexpression in human cells showing YY1 binding at rs877819 controls WDFY4 transcription\",\n      \"pmids\": [\"22972472\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Which immune cell types are most affected by reduced WDFY4 transcription in vivo remains undefined\",\n        \"Whether other transcription factors co-regulate WDFY4 at this locus is untested\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identification of WDFY4 as an essential, specific mediator of cross-presentation in cDC1s established its core molecular function — enabling MHC-I loading of exogenous antigens without affecting MHC-II presentation, cDC1 development, or IL-12 production.\",\n      \"evidence\": \"CRISPR screen in cDC1 line and Wdfy4-/- mice with viral, parasitic, and tumor antigen challenge models\",\n      \"pmids\": [\"30409884\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The precise molecular step in the cross-presentation pathway where WDFY4 acts (e.g., phagosome-to-cytosol export, proteasomal access, peptide loading) is unknown\",\n        \"Whether WDFY4 functions as a scaffold, transporter, or membrane remodeler has not been determined\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstrating that WDFY4 physically interacts with TLR3/4/9 and MDA5 and augments NF-κB activation revealed a second functional axis beyond cross-presentation — amplification of innate immune signaling.\",\n      \"evidence\": \"Co-immunoprecipitation with TLRs and MDA5, NF-κB luciferase reporter assays, and apoptosis assays showing enhanced MDA5-induced apoptosis by truncated WDFY4\",\n      \"pmids\": [\"29331962\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Interactions validated by Co-IP only without reciprocal pull-down or endogenous IP in primary cells\",\n        \"Mechanism by which WDFY4 augments NF-κB (scaffolding vs. signalosome assembly) is not defined\",\n        \"Relevance of truncated isoform in physiological settings beyond overexpression systems is unclear\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Conditional deletion in B cells revealed that WDFY4 restrains noncanonical autophagy (LC3 lipidation independent of p62/Beclin1) and is required for normal B cell development and humoral immunity, connecting it to SLE pathogenesis.\",\n      \"evidence\": \"B cell-conditional Wdfy4 knockout mice with LC3 lipidation assays, B cell subset flow cytometry, pristane-induced lupus model\",\n      \"pmids\": [\"30257884\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular targets of WDFY4-regulated noncanonical autophagy in B cells are uncharacterized\",\n        \"Whether the autophagy phenotype in B cells relates mechanistically to the cross-presentation function in DCs is unknown\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"T cell-conditional knockout established that WDFY4 maintains CD8+ T cell survival by suppressing ROS/Nox2 accumulation and p53-mediated apoptosis while sustaining ERK signaling, broadening its function beyond antigen-presenting cells.\",\n      \"evidence\": \"T cell-conditional Wdfy4 KO mice with ROS quantification, apoptosis assays, p53/ERK pathway analysis, and transplantable tumor models\",\n      \"pmids\": [\"34482201\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct molecular link between WDFY4 and Nox2/ROS regulation is not established\",\n        \"Single-lab finding; independent replication lacking\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Showing that WDFY4 loss promotes Th2 differentiation and exacerbates allergic asthma extended its immune-regulatory role to CD4+ T helper cell polarization.\",\n      \"evidence\": \"Wdfy4-/- mice with in vitro Th2 differentiation and OVA-induced asthma model\",\n      \"pmids\": [\"34425575\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanism by which WDFY4 suppresses Th2 polarization (transcription factor regulation, cytokine signaling) is not defined\",\n        \"Single-lab study without independent confirmation\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrating that WDFY4 deficiency in NOD mice prevents autoimmune diabetes by abolishing cross-presentation of islet antigens proved that WDFY4-dependent cross-presentation is the critical gateway for autoreactive CD8+ T cell priming in organ-specific autoimmunity.\",\n      \"evidence\": \"CRISPR/Cas9 Wdfy4-/- NOD mice with diabetes incidence monitoring, insulitis histology, and cross-presentation/T cell priming assays\",\n      \"pmids\": [\"36940342\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether therapeutic targeting of WDFY4 can reverse established autoimmunity is untested\",\n        \"The specific islet antigens cross-presented via WDFY4 are not identified\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extending WDFY4-dependent cross-presentation to cDC2s demonstrated that this function is not cDC1-exclusive, fundamentally revising the model of which DC subsets require WDFY4 for CD8+ T cell priming.\",\n      \"evidence\": \"cDC1-deficient, cDC2-deficient, and Wdfy4-/- genetic mouse models with immune complex vaccination and tumor rejection assays\",\n      \"pmids\": [\"39918736\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether WDFY4 operates through the same molecular mechanism in cDC2s as in cDC1s is not established\",\n        \"The antigen forms (particulate vs. soluble vs. immune complex) that differentially engage WDFY4 in each DC subset remain unclear\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Discovery of a WDFY4–LAPTM5 interaction that promotes endothelial ferroptosis via suppression of the CDC42/mTOR/4EBP1/SLC7A11 axis revealed a non-immune function in vascular biology and atherosclerosis.\",\n      \"evidence\": \"Co-IP, co-localization, endothelium-specific WDFY4 knockout in ApoE-/- mice on HFD with pathway inhibitor rescue\",\n      \"pmids\": [\"40755163\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single-lab finding; endothelial ferroptosis link not independently replicated\",\n        \"Whether the LAPTM5 interaction is relevant to WDFY4's immune cell functions is unknown\",\n        \"Structural basis for WDFY4–LAPTM5 interaction not determined\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The precise molecular step at which WDFY4 acts in the cross-presentation pathway — whether it facilitates antigen escape from endosomes, phagosomal membrane integrity, peptide–MHC-I loading, or vesicular trafficking — remains the central unresolved question.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No structural model of WDFY4 or its BEACH domain in the context of cross-presentation machinery exists\",\n        \"Direct substrates or cargo of WDFY4 in DCs have not been identified\",\n        \"Relationship between WDFY4's roles in autophagy regulation, innate signaling, and cross-presentation is mechanistically unintegrated\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 1, 2, 3, 4, 5, 6]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [5, 7]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"TLR3\",\n      \"TLR4\",\n      \"TLR9\",\n      \"MDA5\",\n      \"LAPTM5\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}