Epigenetic Regulation of KSHV - PROJECT SUMMARY/ABSTRACT Kaposi’s Sarcoma-associated herpesvirus (KSHV), also known as Human Herpesvirus 8 (HHV8), is the etiological agent of the human malignancies Kaposi’s sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman’s disease (MCD). KS is the most common AIDS-defining malignancy and represents the leading cause of cancer in sub-Saharan African men. Despite KSHV associated malignancies having a unifying variable (KSHV), no effective viral specific biomarker exists. Current viral monitoring commonly relies on crude viral PCR load levels, is not informative of viral activity, and is not currently recommended for monitoring of disease response within National Comprehensive Cancer Network (NCCN) guidelines. KSHV establishes lifelong infection and generally exists in either a latent or lytic state. Latency is the default state and is characterized by viral expression of a very limited subset of genes. On the other hand, lytic is full expression of the viral genome with production of infectious progeny. KSHV derived malignancy is thought to depend on gene products from both latent and lytic states. Therefore, understanding regulation of KSHV latent/lytic balance has long been a highly sought after goal. Epigenetic regulation of viral genes is a well-known mechanism for gene control; however, this remains an incompletely explored area within KSHV, particularly in regards to viral DNA methylation. Previous work has shown variation in KSHV DNA methylation patterns globally in cell lines and at the lytic origin of replication in primary samples. We hypothesize that KSHV DNA methylation is dynamic during latent/lytic shift and that overall patterns will be predictive of viral activity in vivo which may represent a novel biomarker. To explore KSHV DNA methylation, we have created a novel approach for high throughput multi-locus methylation investigation within KSHV samples. We propose to characterize KSHV methylation dynamics in vitro during latent/lytic states utilizing this approach. Further, we aim to validate overall KSHV methylation pattern as a novel biomarker for KSHV associated disease by analyzing primary patient samples from an internal biorepository and from a clinical trial . Collectively, the proposed studies will fill a distinct gap in our basic understanding of KSHV virology; DNA methylation dynamics during the crucial latent/lytic shift and in differing disease contexts. Additionally, we aim to generate a novel biomarker in KSHV associated disease to be utilized as a potential proxy of viral activity, disease response, and prognosis.
