Autologous Organoid‐T Cell Co‐Culture Platform for Modeling of Immune‐Mediated Drug‐Induced Liver Injury

Modeling adaptive immune responses in induced pluripotent stem cell (iPSC)-derived liver systems remains a critical barrier for studying immune-mediated hepatic diseases, including idiosyncratic drug-induced liver injury (iDILI). Conventional hepatotoxicity models lack the components required to capture patient-specific, T cell-mediated injury. Here, a scalable and matrix-free human liver organoid (HLO) microarray platform is presented that enables controlled co-culture of Human Leukocyte Antigen (HLA)-genotyped, iPSC-derived HLOs with autologous CD8⁺ T cells. This immune-competent system supports antigen-specific T cell activation and reproduces cytotoxic effector responses in a genetically defined context. As a proof-of-concept, the platform models clinically relevant iDILI caused by flucloxacillin in HLA-B*57:01 carriers, recapitulating CD8⁺ T cell proliferation, hepatocyte apoptosis, and variability in immune responses across donors. The system captures hallmark features of adaptive immune-mediated hepatotoxicity, including secretion of tumor necrosis factor-alpha and Granzyme B, and cytokeratin-18 release from injured hepatocytes. By linking genetic susceptibility with functional immune outcomes, this platform provides a modular and scalable approach for evaluating immune-mediated toxicities. The method offers broad utility for mechanistic studies of drug hypersensitivity, immune-related adverse events, and preclinical safety assessment in support of precision medicine.