Mitochondrial and lipid metabolism rewiring during HEV infection.

Hepatitis E virus (HEV), a leading cause of acute and chronic viral hepatitis, poses a persistent global health challenge. A deeper mechanistic understanding of virus-host interactions is critical for identifying therapeutic targets to mitigate HEV-associated disease. In this study, we employ a systems biology framework to comprehensively map metabolic and bioenergetic alterations induced by HEV genotypes 1 and 3 in HepG2/C3a-MAVS-KD cells, a robust model of HEV infection, enabling reliable assessment of virus- and host-driven cellular changes. Our analyses reveal extensive remodelling of host metabolism, including reprogramming of the tricarboxylic acid (TCA) cycle, mitochondrial oxidative phosphorylation (OXPHOS), fatty acid metabolism, and β-oxidation-pathways that collectively sustain the energetic and biosynthetic demands of viral infection. HEV infection also reshapes the cellular lipidome, increasing levels of long-chain neutral lipids and lipid droplet abundance, alongside elevated levels of pro-inflammatory oxylipins. Functional metabolic assays demonstrate a reliance on lipid-fuelled OXPHOS rather than glycolysis for efficient HEV infection. These findings uncover critical host metabolic dependencies exploited by HEV and offer a conceptual framework for targeting metabolic hubs as a therapeutic strategy against HEV infection. Author Summary: Viruses are obligate intracellular pathogens that reprogramme host cellular machinery to their advantage. Yet, the extent to which Hepatitis E virus (HEV) infection orchestrates metabolic reprogramming, and the implications of these changes for viral fitness, remain poorly defined. By integrating large-scale proteomics with lipid metabolic profiling, we delineate molecular strategies through which HEV subverts host lipid metabolism and mitochondrial function. Our findings provide mechanistic insight into how HEV infection modulates host metabolic pathways to its advantage, highlighting potential targets for therapeutic intervention.