EMCV Replication in BHK-21 in Vitro is Mediated by Caveolin-1, Actin, Dynamin-Dependent Endocytic Pathway

Abstract

Background: Encephalomycarditis virus is a member of Cardiovirus, belongs to the family Picornaviridae, and can infect different domestic and wild animals. However, the endocytic pathway by which EMCV infected BHK-21 cells remains unclear. In this study, endocytic pathway used by EMCV replication in BHK-21 cells was elucidated.Methods: The function of numerous cellular key factors implicated in the various endocytic mechanisms known to date were systematic detected using chemical inhibitors. Furthermore, RNA interference (RNAi) silencing, the overexpression of dominant protein combined to virus infectivity assays, and confocal imaging to examine which cellular molecules involved in the infection process were also analyzed.Results: The results indicated that the EMCV replication was related to endocytosis. However, neither clathrin nor macropinocytosis pathway was involved in virus infection. QRT-PCR and WB analyses showed that caveolin-1 were significantly up-regulated in EMCV infected BHK-21 cells. Immune-fluorescent confocal microscopy analysis showed that caveolin-1 was temporally co-localized with EMCV VP1 at the early stage of EMCV infection. Overexpressed caveolin-1 or downregulated caveolin-1 expression influenced the EMCV infection. Furthermore, EMCV infection was found to depend on dynamin and actin by chemical inhibitors resulted in diminished of virus infection.Conclusions: EMCV replication in BHK-21 cells via caveolin-1, dynamin, and actin-dependent endocytosis pathways.