Abstract

Elevated levels of proinflammatory cytokines associated with infection and inflammation can modulate cytochrome P450 enzymes, leading to potential disease-drug interactions and altered small-molecule drug disposition. We established a human-derived hepatocyte-Kupffer cell (Hep:KC) coculture model to assess the indirect cytokine impact on hepatocytes through stimulation of KC-mediated cytokine release and compared this model with hepatocytes alone. Characterization of Hep:KC cocultures showed an inflammation response after treatment with lipopolysaccharide and interleukin (IL)-6 (indicated by secretion of various cytokines). Additionally, IL-6 exposure upregulated acute-phase proteins (C-reactive protein, alpha-1-acid glycoprotein, and serum amyloid A2) and downregulated CYP3A4. Compared with hepatocytes alone, Hep:KC cocultures showed enhanced IL-1β–mediated effects but less impact from both IL-2 and IL-23. Hep:KC cocultures treated with IL-1β exhibited a higher release of proinflammatory cytokines, an increased upregulation of acute-phase proteins, and a larger extent of metabolic enzyme and transporter suppression. IC₅₀ values for IL-1β–mediated CYP3A4 suppression were lower in Hep:KC cocultures (98.0–144 pg/ml) compared with hepatocytes alone (IC₅₀ > 5000 pg/ml). Cytochrome suppression was preventable by blocking IL-1β interaction with IL-1R1 using an antagonist cytokine or an anti-IL-1β antibody. Unlike IL-1β, IL-6–mediated effects were comparable between hepatocyte monocultures and Hep:KC cocultures. IL-2 and IL-23 caused a negligible inflammation response and a minimal inhibition of CYP3A4. In both hepatocyte monocultures and Hep:KC cocultures, IL-2RB and IL-23R were undetectable, whereas IL-6R and IL-1R1 levels were higher in Hep:KC cocultures. In summary, compared with hepatocyte monocultures, the Hep:KC coculture system is a more robust in vitro model for studying the impact of proinflammatory cytokines on metabolic enzymes.