Activity And Mechanism Of Action Of Way-150138 Against Herpes Simplex Virus Type 2

Abstract

Resistance to currently approved drugs and a medical need to treat beta and gamma herpesviruses merit the identification and development of alternative drug therapies for herpesviral infections. Previous research has suggested that a novel class of small molecule thiourea analogs target the UL6 portal protein of HSV-1 and HSV-2, disrupting the replication cycle during the viral DNA encapsidation process. Specifically, WAY-150138 compound was shown to have notable inhibitory effect against HSV-1. The compound’s reported lack of efficacy against HSV-2 remained puzzling considering the high amount of genetic conservation shared in the portal protein between HSV-1 and HSV-2. The studies presented in this thesis sought to resolve this issue. Viral yield assays were conducted for multiple strains of HSV-1 and HSV-2 in the presence of compound, and viral titers were calculated via direct plaque assay on Vero cell monolayers. Contrary to previous studies, WAY-150138 exhibited a similar inhibitory effect against both HSV-1 and HSV-2. To further investigate the molecular mechanism of thiourea compounds that target encapsidation, the HSV-2 portal homolog, encoded by the UL6 gene, was used to generate an rb-BAC-pUL6 protein. After full-length expression of the portal protein in a recombinant baculovirus system, sucrose gradient fractionation provided samples containing enriched amounts of pUL6 for further biochemical analysis.