The Effects of DNA Topoisomerase 1 Alteration in Herpes Simplex Virus Type 1 Infections

Abstract

Herpes simplex virus type 1 (HSV‐1) is a universal human pathogen that infects nearly 70% of the population. In addition to producing its own viral factors, HSV‐1 utilizes numerous host proteins to facilitate its infection cycle. One host protein of particular interest, found to specifically interact with the HSV‐1 genome throughout replication, is human topoisomerase 1 (Top1). In human cells, Top1 is an enzyme required for normal growth and development. Cellular Top1 ensures proper transcription and DNA replication by creating single stranded nicks in DNA to relieve topological stress and allow for relaxation of supercoiled DNA. Based on its role in cellular processes, we believe that Top1 aids in the regulation of viral transcription and/or replication. We therefore hypothesize that altering Top1 expression in HSV‐1 infected cells will decrease viral yield by not allowing for an efficient infection cycle. To alter Top1 expression, the commercial inhibitor, camptothecin (CPT) was used. Our studies revealed the novel observation that Top1 inhibition via CPT does reduce viral yield. Currently, an inducible Top1 shRNA knockdown cell line is being created as another method of alteration. In the future, we will determine if viral transcription or DNA replication are altered after Top1 inhibition or knockdown. These studies will further pinpoint the role of Top1 in HSV‐1 infection.