Cell Susceptibility to Baculovirus Transduction and Echovirus Infection Is Modified by Protein Kinase C Phosphorylation and Vimentin Organization

Abstract

Some cell types are more susceptible to viral gene transfer or virus infection than others, irrespective of the number of viral receptors or virus binding efficacy on their surfaces. In order to characterize the cell-line-specific features contributing to efficient virus entry, we studied two cell lines (Ea.hy926 and MG-63) that are nearly nonpermissive to insect-specific baculovirus (BV) and the human enterovirus echovirus 1 (EV1) and compared their characteristics with those of a highly permissive (HepG2) cell line. All the cell lines contained high levels of viral receptors on their surfaces, and virus binding was shown to be efficient. However, in nonpermissive cells, BV and its receptor, syndecan 1, were unable to internalize in the cells and formed large aggregates near the cell surface. Accordingly, EV1 had a low infection rate in nonpermissive cells but was still able to internalize the cells, suggesting that the postinternalization step of the virus was impaired. The nonpermissive and permissive cell lines showed differential expression of syntenin, filamentous actin, vimentin, and phosphorylated protein kinase C subtype ␣ (pPKC␣). The nonpermissive nature of the cells could be modulated by the choice of culture medium. RPMI medium could partially rescue infection/transduction and concomitantly showed lower syntenin expression, a modified vimentin network, and altered activities of PKC subtypes PKC␣ and PKC. The observed changes in PKC␣ and PKC activation caused alterations in the vimentin organization, leading to efficient BV transduction and EV1 infection. This study identifies PKC␣, PKC, and vimentin as key factors affecting efficient infection and transduction by EV1 and BV, respectively.

6-O- andN-Sulfated Syndecan-1 Promotes Baculovirus Binding and Entry into Mammalian Cells

“…Baculovirus is able to bind to and interact with SDC-1 of EA.hy926 cells, but in this nonpermissive cell line it cannot reach the nucleus where the transgene expression takes place (18). Additionally, we showed recently that the dynamics of vimentin expression and the phosphorylation status of protein kinase C alpha (PKC-␣) and -ε regulate the nonpermissive phenotype of EA.hy926 and MG-63 cells, affecting baculovirus transduction (52). The phenomenon of the virus getting trapped and aggregated in EA.hy926 cells has also been reported in the case of AAV-2, a virus known to apply HSPG as a receptor (53).…”

Comparative proteomic analysis of hemolymph proteins from Autographa californica multiple nucleopolyhedrovirus (AcMNPV)-sensitive or -resistant silkworm strains during infections

“…In the case of NPVs, no RNAi pathway proteins from Lepidopteran insects have been reported as suppressors limiting viral replications. Interestingly, emerging research shows that potential host factors are also involved in recognition/replication of NPVs (Terenius, 2008;Kang et al, 2011;Jiang et al, 2012;Lü et al, 2013;Turkki et al, 2013;Makkonen et al, 2013;Jin et al, 2014). However, factors affecting host cell permissiveness to BV infection/transduction remain largely unknown.…”

Human Enterovirus Group B Viruses Rely on Vimentin Dynamics for Efficient Processing of Viral Nonstructural Proteins

“…In our earlier studies, we noticed that the morphology of the cellular vimentin network correlated with echovirus-1 (EV-1) infection efficiency in tested human cell lines (14). Changes in the vimentin network brought about with different media and treatments correlated with successful baculovirus transduction and echovirus infection, suggesting that the vimentin network has a previously unknown role in infection.…”