Equine herpesvirus type 1 (EHV-1)-induced rearrangements of actin filaments in productively infected primary murine neurons

Abstract

Equine herpesvirus type 1 (EHV-1) causes respiratory disease, abortion and neurological disorders in horses. In the present study, we investigated reorganization of the cytoskeleton in neurons infected with two EHV-1 strains: Jan-E (wild-type strain) and Rac-H (attenuated strain). The studies were performed on primary murine neurons, which are an excellent model for studying neurotropism and neurovirulence of EHV-1. We have demonstrated for the first time that EHV-1 infection causes rearrangements in the actin network of neurons that are dependent on the virus strain and its adaptation to cell culture in vitro. Immunofluorescent labeling and confocal microscopy revealed the formation of long, thin projections in neurons infected with the Jan-E strain, which was probably associated with enhanced intracellular spread of the virus. The EHV-1 Rac-H strain caused disruption of the microfilaments system and general depolymerization of actin, but treatment of neurons with cytochalasin D or latrunculin A resulted in limitation of viral replication. It can therefore be assumed that actin filaments are required only at the early stages of infection. Our results allow us to suggest that the actin cytoskeleton participates in EHV-1 infection of primary murine neurons but is not essential, and that other components of the cytoskeleton and/or cellular mechanisms may be also involved during EHV-1 infection.

Replication kinetics of neuropathogenic and non-neuropathogenic equine herpesvirus type 1 (EHV-1) strains in primary murine neurons and ED cell line

“…Further analysis of the cytoskeleton rearrangement also indicated that each virus affects F-actin network in different way. The results are consistent with our previous studies (Turowska et al 2010, Słońska et al 2014. The Rac-H EHV-1 strain caused the destruction of the actin cytoskeleton in the infected neurons and ED cells.…”

“…The above-mentioned structures seemed to contribute to the direct spread of virus particles to adjacent cells without being exposed to the extracellular space. It seems that the neuropathogenic EHV-1 strain uses the same strategy to infect adjacent cells as the Jan-E EHV-1 (Słońska et al 2014). The literature data suggest that other herpesviruses also induce the formation of similar actin projections -HHV-1 in the Vero cells and BHK, VZV in the HFF cells or SuHV-1 in RK13 and PK15 cells (Favoreel et al 2005(Favoreel et al , 2007.…”

Function of myosin during entry and egress of equid herpesvirus type 1 in primary murine neurons

“…Consequently, we observed a non-uniform effect of tested EHV-1 strains on the cytoskeleton of the infected neurons. It seems very likely that both strains developed different strategies and mechanisms of interaction with the host cytoskeleton to facilitate efficient use of intracellular transport (Turowska et al, 2010;Słońska et al, 2014).…”

“…In our previous studies we showed that during EHV-1 infection of primary murine neurons, both types of interactions between virus and actin cytoskeleton occurred. Jan-E EHV-1 (field strain) has caused formation of actin-containing projections that established intimate contact with adjacent cells and served to propel newly produced virions from cell to cell, whereas Rac-H EHV-1 (reference strain) induced the destruction of actin filaments, apparently to affect efficient egress (Słońska et al, 2014). As reported in literature, a number of viruses overcome a dense network of cortical actin presumably by myosin.…”

Acyclovir and trichostatin A modulate EHV-1 replication in murine neurons in vitro

“…A detailed study of interactions between EHV-1 and host cells at the molecular level would be possible using a pure population of neurons. Such a model would also help avoid many confounding issues associated with studying latency and reactivation in vivo that can potentially obscure virus-cell interactions (8,9,20). In the present study, the main focus was on creating an appropriate in vitro model in which the complete suppression, as well as the restoration, of EHV-1 replication will be possible.…”