Gene expression profiling in human primary hepatocytes and human induced pluripotent stem cell-derived hepatocytes before and after IL-1ß Treatment
The shared transmission routes of hepatitis B virus (HBV) and hepatitis C virus (HCV) result in coinfections that accelerate and exacerbate liver disease. The clinical burden is further exacerbated in the era of direct-acting antivirals (DAAs) against HCV, where reports of HBV reactivation post-DAA treatment in coinfected patients have emerged. Beyond an HCV-induced canonical interferon (IFN) response, the mechanisms through which HCV suppresses HBV remain poorly understood. Here, we employ a multicellular liver culture system, co-culturing human-induced pluripotent stem cells (hiPSCs)-derived hepatocytes, hepatic stellate cells and macrophages, that supports productive HCV and HBV infection and replicates clinical coinfection dynamics. We demonstrate that IL1ß from macrophages activated by HCV modulates host factors involved in HBV infection independent of IFN signaling. By combining bioinformatic predictions with reporter assay validation, we identified the transcriptional mediators of these changes. Hepatocytes downregulate expression of HBV receptor SLC10A1  due to induction of a truncated C/EBPß isoform, which negatively regulates the full-length variant's activity. Simultaneously, IL1ß induces the expression of ISG20, a known anti-HBV factor, through USF1 phosphorylation. Finally, we show that a modified treatment protocol combining DAA with an HBV entry inhibitor effectively prevents HBV reactivation. Our findings position this liver culture platform as a tool not only for detailed mechanistic dissection of the complex multicellular responses in HBV-HCV coinfection, but also for nominating and testing future therapeutic avenues for coinfected patients. Overall design: To unravel the mechanisms underlying IL1ß-induced suppression of HBV infection, we conducted transcriptomic analysis on primary human hepatocytes and human-induced pluripotent stem cells (hiPSCs)-derived hepatocytes treated with two distinct IL1ß concentrations (i.e., 10ng/ml and 20ng/ml) for a 24-hour duration. Our objective was to identify differentially expressed genes (DEGs) in hepatocytes regulated by IL1ß and cross-reference these DEGs with known host factors that either promote or inhibit HBV infection.