The complex mechanism of Ebola virus (EBOV) entry into host cells, triggered by the EBOV surface glycoprotein GP, is only partially understood. In previous drug screening work at the Jean Mérieux BSL4 facilities, Poly(sodium 4-styrenesulphonate) (PSS), an anionic compound, was identified as a potent inhibitor of EBOV infection in Vero E6 cells. Through the utilisation of a pre-existing surrogate system composed of recombinant vesicular stomatitis viruses expressing Zaire GP instead of the typical VSV-G protein, additional experiments involving passages of PSS resulted in the identification of viruses carrying a single GP mutation, specifically E304A, that exhibited resistance to the aforementioned drug. We first produced and characterised two recombinant viruses, VSVEB-WT and VSVEB-E304A, and found that E304A had clear growth advantages over the WT. Further investigation revealed that E304A's increased
infectivity likely resulted from an additional Furin cleavage of the GP1 subunit. This correlation was tested by generating rescued recombinant VSV with mutations at the Furin-like cleavage site of GP1. Finally, BSL4 experiments using recombinant Ebola viruses bearing either WT GP or the E304A mutation demonstrated that the E304A mutation enhanced virus entry efficiency, and wild type GP presented both protein forms (GP1 and GP1 cleaved) in a heterogeneous state. These findings suggest a revised model for the biology of EBOV, with potential implications for future research and drug development.
Gratuit
Disciplines