Ebola Virus Uptake into Polarized Cells from the Apical Surface.

Meng Hu,Fei Wang,Xiaowei Zhang,Zhiping Zhang,Wei Li,Zongqiang Cui,Xian-En Zhang

doi:10.3390/v11121117

Abstract

Ebola virus (EBOV) causes severe hemorrhagic fever with high mortality rates. EBOV can infect many types of cells. During severe EBOV infection, polarized epithelial and endothelial cells are damaged, which promotes vascular instability and dysregulation. However, the mechanism causing these symptoms is largely unknown. Here, we studied virus infection in polarized Vero C1008 cells grown on semipermeable Transwell by using EGFP-labeled Ebola virus-like particles (VLPs). Our results showed that Ebola VLPs preferred to enter polarized Vero cells from the apical cell surface. Furthermore, we showed that the EBOV receptors TIM-1 and Axl were distributed apically, which could be responsible for mediating efficient apical viral entry. Macropinocytosis and intracellular receptor Niemann–Pick type C1 (NPC1) had no polarized distribution, although they played roles in virus entry. This study provides a new view of EBOV uptake and cell polarization, which facilitates a further understanding of EBOV infection and pathogenesis.

Highlights

The filovirus Ebola virus (EBOV) is an enveloped, negative-sense, single-stranded RNA virus [1,2,3].The Ebolavirus genus contains five species, Bundibugyo ebolavirus, Reston ebolavirus, Sudan ebolavirus, Tai Forest ebolavirus, and Zaire ebolavirus
To assess the mechanism of EBOV uptake, we established fluorescently labeled Ebola virus-like particles (VLPs) consisting of matrix proteins VP40 and GP
The expression of target proteins was measured by western blot analysis, and the results demonstrated that EGFP and VP40 were coexpressed (Figure S2B)

Summary

Introduction

The filovirus Ebola virus (EBOV) is an enveloped, negative-sense, single-stranded RNA virus [1,2,3].The Ebolavirus genus contains five species, Bundibugyo ebolavirus, Reston ebolavirus, Sudan ebolavirus, Tai Forest ebolavirus, and Zaire ebolavirus. Members of all species can infect humans, but Reston virus is the only member of the ebolavirus species that seems to be avirulent in humans [4,5]. Expression of VP40 protein alone is sufficient for assembly and formation of virus-like particles (VLPs) that are similar in size and shape [10,11] and nearly indistinguishable from the authentic virion [12]. It has been well documented that Ebola VLPs have the same capability to infect cells as EBOV. EBOV GP, a prototypic class I viral fusion protein, is the only viral surface protein and exists as a homotrimer [13]. During transit to cell surface, GP can be cleaved into GP1 and GP2 subunits by furin-like proteases [14,15]. GP1 and GP2 are disulfide linked and form the mature GP1,2 complex

Methods

Results

Conclusion