{"id":"e97f00c4-09c9-5485-9962-e6fd6b62d503","stable_key":"research:il2-activates-stat5-tfh-context","predicate":"activates","statement":"IL-2 signaling activates STAT5 in the studied CD4 T-cell differentiation context.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"literature_reviewed:direct_experimental","direction":"positive","is_public":true,"mechanism_event_id":"2c752fa4-ea84-5971-a88e-76ceba34d30a","mechanism_event_label":"IL-2 engages a signal that can oppose Tfh development.","subject":{"id":"94bdd5a2-efea-569c-84ff-ecca28ab1b6a","slug":"il2-protein","display_name":"IL-2","entity_type_key":"cytokine"},"object":{"id":"d8de1e6a-fdad-52a0-8b9d-c9ea510a0238","slug":"stat5","display_name":"STAT5","entity_type_key":"protein_family"},"evidence_count":1,"mechanism_event":{"id":"2c752fa4-ea84-5971-a88e-76ceba34d30a","stable_key":"research:il2-activates-stat5-tfh-context","event_type":"signal-transduction","label":"IL-2 engages a signal that can oppose Tfh development.","description":"IL-2 signaling activates STAT5 in the studied CD4 T-cell differentiation context.","status":"active","compartment":null,"participants":[{"entity":{"id":"94bdd5a2-efea-569c-84ff-ecca28ab1b6a","slug":"il2-protein","display_name":"IL-2","entity_type_key":"cytokine"},"role":"stimulus","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d8de1e6a-fdad-52a0-8b9d-c9ea510a0238","slug":"stat5","display_name":"STAT5","entity_type_key":"protein_family"},"role":"signaling-factor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"5fa7b95f-d2ef-50d6-97b7-df5b1bcb10de","slug":"t-cell","display_name":"T cell","entity_type_key":"cell_type"},"role":"responding-cell","stoichiometry":null,"state_label":"activated CD4","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cell_type","value_text":"antigen-specific CD4 T cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"LCMV infection and signaling perturbations","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"No selenium intervention in this study.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"organism","value_text":"mouse","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"914eb4a4-5065-5d71-92ad-9389cdf0899e","evidence_kind":"curated_literature_summary","locator":"lines 918-928","start_line":918,"end_line":928,"excerpt":"## il2-activates-stat5-tfh-context\n\nIL-2 engages a signal that can oppose Tfh development.\n\nIL-2 signaling activates STAT5 in the studied CD4 T-cell differentiation context.\n\nOrganism: mouse\nCell type: antigen-specific CD4 T cells\nExperimental model: LCMV infection and signaling perturbations\nLimitations: No selenium intervention in this study.\nPrimary reference: [STAT5 is a potent negative regulator of TFH cell differentiation](https://pmc.ncbi.nlm.nih.gov/articles/PMC3281266/)","model_system":"LCMV infection and signaling perturbations","directness":"author_interpretation","verification_status":"secondary_verified","notes":"Curated summary; inspect the linked primary papers for original methods and results.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f892f13-06ea-5199-a33c-a703f35c80ae","stable_key":"selenium-research-2026-09-17","title":"Selenium: literature corrections and mechanism additions","document_type":"curated_literature_review","citation_label":"Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually","file_path":"","sha256":"0b818b10c1c7120e5caf7f4d4019d7bd025d745692e424f515d3ef903c9ab7f3","revision_id":"80984e03-5f0f-5877-8094-afef7637444e","review_status":"secondary_verified","notes":"Secondary curated summaries of primary experiments, with explicit models and limitations. Not archived primary full text."}}],"relations":[],"conflicts":[],"corrections":[],"research":{"topic":"t-cell-fate","plain_language":"IL-2 engages a signal that can oppose Tfh development.","evidence_scope":"direct_experimental","papers":[{"key":"johnston-2012-stat5-tfh","title":"STAT5 is a potent negative regulator of TFH cell differentiation","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC3281266/","doi":"10.1084/jem.20111174","year":2012,"model":"Mouse LCMV infection, transferred antigen-specific CD4 cells and genetic perturbations","summary":"Tests IL-2/STAT5 suppression of Tfh differentiation and its dependence on Blimp-1."}]}}