HIVIL: A human in vitro inflammatory liver model recapitulates immune-associated drug effects with high predictivity.

DILI (Drug Induced Liver Injury) is one of leading cause of failure in drug development due to adverse reaction outcomes and health hazards. Besides, understanding DILI is challenging due to lack of relevant in vitro models] that recapitulate human in vivo physiological responses. Current in vitro models employing primary human Kupffer cells (PHKCs) or alternative cells such as THP-1 derived macrophages are either complex or do not recapitulate physiological drug-induced cytokine responses. We leveraged on human iPSC derived Kupffer cells (iKCs) that functionally resemble PHKCs to establish a human in vitro inflammatory liver model (HIVIL) that is complex enough to be physiological and simple enough to be robust. HIVIL, comprising of iKCs co-cultured with iPSCs derived hepatocytes can recapitulate physiological levels of DILI associated inflammatory response of known DILI drugs in vitro. Out of 18 drug candidates tested, the cytokine responses of 16 drugs correlated (88.9 %) well with the reported serum cytokine profiles of DILI patients implying a closer-to-physiological relevant immune responses and cytochrome P450 expression . Moreover, HIVIL model was able to mechanistically distinguish the TNF⍺ mediated hepatotoxic effect of Trovafloxacin over Levofloxacin. RNA-Seq analysis provided further insight into the interactions between the cytokines and drug-induced liver injury. In contrast, HIVIL using THP-1 derived macrophages instead of iKCs did not recapitulate the cytokine responses upon treatment with paradigm compounds, demonstrating the importance of KCs-produced cytokines on hepatocyte xenobiotic metabolism. In summary, our study demonstrates for the first time, the use of iKCs and iHeps as a simple, robust and physiologically relevant in vitro drug testing model for DILI candidates.