The development and characterization of recombinant HEV reporter genomes for the identification of positive and negative regulators of HEV host tropism

Abstract

Hepatitis E virus (HEV) is a quasi-enveloped, positive sense, single stranded RNA virus of the hepeviridae family, with a genome composed of three open reading frames. HEV causes hepatitis E worldwide, leading to 70,000 deaths a year, with a mortality rate among pregnant women as high as 30%. Hepatitis E poses a major public health threat not only in developing countries where it is transmitted fecal-orally, but also in developed nations around the world through food-borne transmissions. As HEV is primarily transmitted to humans from animal reservoirs in developed nations, evaluating the host tropism of the virus can prove useful in a global health campaign. Preliminary work in the Ploss lab shows that replication levels of the virus are 100 to 1000 times lower in murine than human hepatoma cells. I hypothesize that these observations can putatively be explained by dominant negative regulators that hinder HEV replication or absent human specific cofactors for HEV replication in rodent cells. The major aims of this project include the generation of recombinant HEV genomes containing selectable and fluorescent markers that will be useful in the characterization of HEV replication in cell culture. With the use of a novel transcomplementation assay, virally encapsulated recombinant genomes will be developed and used in future loss and gain of function screenings to identify host factors essential for robust HEV infection. Results from this work will lead to an improved understanding of host-virus interactions, contribute to the development of animal models to study HEV, and inform public health efforts to contain HEV spread.