T cell fate is dictated by different antigen-presenting cells in response to dietary versus gut epithelial self-antigen.

Different antigen-presenting cells dictate T cell fates in response to dietary versus gut epithelial self-antigen, with distinct APC dependencies linked to immune outcomes.

• Why it matters: Understanding how T cell responses are regulated by different APCs in the gut is crucial for predicting and managing gut autoimmunity and immune responses to food and microbes.
• What they did: The study compared ovalbumin-specific T cell fates in mice fed OVA or expressing epithelial OVA variants, analyzing responses at baseline, after reovirus, and helminth infections, focusing on APC roles.
• The result: BATF3 + APCs were essential for CD4+ T cell proliferation only in cOVA mice but promoted Treg differentiation across all models, while RORγt + APCs were exclusively required for Treg induction by dietary OVA, linking APC dependence to pathology susceptibility.