Cytoskeletal Vimentin Directs Cell‐Cell Transmission of Hepatitis C Virus

Abstract Hepatitis C virus (HCV) is a major human pathogen causing liver diseases. Although direct‐acting antiviral agents effectively inhibit HCV infection, cell–cell transmission remains a critical venue for HCV persistence in vivo. However, the underlying mechanism of how HCV spreads intercellularly remains elusive. Here, we demonstrated that vimentin, a host intermediate filaments protein, is dispensable for HCV infection in cell models but essential for simulated in vivo infection in differentiated hepatocytes. Genetic removal of vimentin markedly and specifically disrupts HCV cell–cell transmission without influencing cell‐free infection. Through mutual co‐immunoprecipitation screening, we identified that the N‐terminal 1–95 amino acids of vimentin exclusively interact with the HCV envelope protein E1. Introducing either full‐length or head region of vimentin is capable of restoring the cell–cell transmission deficiency in vimentin‐knockout cells. Moreover, we showed that it is vimentin on the plasma membrane of recipient cells that orchestrates HCV cell–cell transmission. Consequently, vimentin antibody, either applied individually or in combination with HCV neutralizing antibody, exerts pronounced inhibition of HCV cell–cell transmission. Together, the results unveil an unrecognized function of vimentin as a unique venue dominating viral transmission, providing novel insights into propelling advancements in vimentin‐targeted anti‐HCV therapies.