Role of peroxisomes in the replication cycle of Hepatitis E virus

Introduction

Hepatitis E virus (HEV) infections represent the leading cause of acute viral hepatitis globally, accounting for over 20 million cases annually. Despite their prevalence, our understanding of the HEV replication cycle and its interactions with the host cell remains limited. Recent studies have highlighted the involvement of peroxisomes—organelles essential for lipid and fatty acid metabolism, detoxification processes, and innate immune responses—in the life cycles of various viruses. This study aims to elucidate the role of peroxisomes in the HEV replication cycle and to determine their significance as host organelles in HEV infection.

Material and Methods

HEK T-REx293 cells with individual knockouts of eleven peroxins (PEX) essential for peroxisome biogenesis were generated. Cells were infected with HEV genotype 3 (Kernow-C1 p6), and infection was assessed using focus forming assays. Additionally, a Gaussia luciferase reporter replicon was used to evaluate replication in the knockout lines. Wild-type cells served as controls.

Results

HEV infection assays showed a two- to three-fold increase in focus forming units in PEX1- and PEX5-knockout cells compared to wild-type controls, indicating enhanced viral replication. This observation was corroborated by the Gaussia luciferase-based replication assay, which demonstrated a similar increase in reporter activity in PEX1-KO and PEX5-KO cells. Conversely, knockout of PEX3, PEX7, and PEX10 resulted in a marked reduction in HEV replication capacity.

Conclusion

Collectively, these findings suggest that peroxisomes play a significant role in the HEV replication cycle. Notably, the absence of PEX1 and PEX5, which are essential for the import of matrix proteins into peroxisomes, appears to facilitate HEV replication, whereas disruption of other peroxins impairs viral propagation. These results provide novel insights into the interplay between peroxisomal function and HEV biology and highlight specific peroxins as potential modulators of HEV infection.