Genome-wide screening of haploid stem cells for the discovery of essential genes for marburg virus infection

Identification of host proteins that serve as viral entry factors has enabled insights into virus particle internalization, tropism, and pathogenesis. In this context, haploid cells allow the study of gene knockouts, since recessive mutations will show a clear phenotype due to the absence of a 2nd gene copy. The study of highly pathogenic viruses (HiPVs) present significant challenges due to the requirement for BSL-4 containments. Indeed it has been proposed to use the Vesicular Stomatitis Virus (VSV) pseudotyped with glycoprotein of HiPVs to study the viral entry pathway. To identify host factors required for Marburg virus infection, we used a mammalian haploid embryonic stem cells library for infection with a recombinant VSV expressing the Marburg virus glycoprotein (rVSV-M) instead of the native glycoprotein. While wild-type cells massively died upon rVSV-M infection, a high number of cells survived within the mutagenized cells. Surviving cells were analyzed by next generation sequencing to identify the mutated genes. Statistical analysis provided a list of 7 genes, potentially involved in rVSV-M entry, which will be validated by infection of specific KO clones. Their role on the viral life cycle will be investigated.