Occludin stalls HCV particle dynamics apart from hepatocyte tight junctions, promoting virion internalization.

Fiche publication

Date publication

avril 2022

Journal

Hepatology (Baltimore, Md.)

Auteurs

Membres identifiés du Cancéropôle Est :
Pr BAUMERT Thomas , Pr MELY Yves , Dr RONDE Philippe

Tous les auteurs :
Deffieu MS, Clément CMH, Dorobantu CM, Partiot E, Bare Y, Faklaris O, Rivière B, Ayala-Nunez NV, Baumert TF, Rondé P, Mély Y, Lucansky V, Gaudin R

Lien Pubmed

https://www.ncbi.nlm.nih.gov/pubmed/35388524

Résumé

Numerous hepatitis C virus (HCV) entry factors have been identified and yet, information regarding their spatiotemporal dynamics is still limited. Specifically, one of the main entry factors of HCV is occludin (OCLN), a protein clustered at tight junctions (TJs), away from HCV landing site. Thus, whether HCV particles slide toward TJs or conversely, OCLN is recruited away from TJs remains debated. Here, we generated CRISPR/Cas9 edited Huh7.5.1 cells expressing endogenous levels of EGFP-OCLN and showed that incoming HCV particles recruit OCLN outside TJs, independently of claudin-1 expression, another important HCV entry factor located at TJs. Using ex vivo organotypic culture of hepatic slices obtained from human liver explants, a physiologically relevant model that preserves the overall tissue architecture, we confirmed that HCV associates with OCLN away from TJs. Furthermore, we showed by live cell imaging that the increased OCLN recruitment beneath HCV particles correlated with lower HCV motility. To decipher the mechanism underlying virus slow-down upon OCLN recruitment, we performed CRISPR knock out of Claudin1 (CLDN1), a HCV entry factor proposed to act upstream of OCLN. Although CLDN1 KO potently inhibits HCV infection, OCLN kept accumulating underneath the particle, indicating that OCLN recruitment is CLDN1-independent. Moreover, inhibition of the phosphorylation of Ezrin, a protein involved in HCV entry that links receptors to the actin cytoskeleton, increased OCLN accumulation and correlated with more efficient HCV internalization. Together, our data provide robust evidence that HCV particles interact with OCLN away from TJs and shed novel mechanistic insights regarding the manipulation of transmembrane receptor localization by extracellular virus particles.