Comprehensive analysis of KSHV gene regulation
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Kaposi fs sarcoma (KS) is the major malignancy occurring in AIDS patients. The etiologic factor for KS has been linked to a human herpesvirus, called Kaposi fs sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8. KSHV DNA is present in virtually all tumors. KSHV exists in two phases in its host; these are the latent state and the lytic replication state. In the latent state only restricted viral genes are transcribed, while in the lytic state more than eighty viral genes are transcribed in cascade fashion. Many AIDS patients are life-long carriers of latent virus, the reactivations of which are unpredictable. Most of the spindle cells in KS tumors are latently infected with the virus, implicating a direct involvement of viral latent genes in the transformation of KS cells. However, KSHV lytic replication also contributes significantly to the formation of KS lesions, by either facilitating viral spread to the target site or releasing paracrine factors to support the growth of the neighboring KS tumor cells. Similarly, the KSHV genome is frequently detected in HIV-associated primary effusion lymphoma (PEL) biopsies, and all cell lines derived from PEL harbor KSHV, with varying degrees of expression of viral latent and lytic genes. It thus appears that both classes of genes contribute to the oncogenic processes. A single KSHV transcriptional activator, K-Rta, is sufficient to induce lytic reactivation of the latent KSHV genome in BCBL-1 cells, a cell line model for PEL. A large number of K-Rta responsive KSHV promoters have been identified. K-Rta also induces several cellular gene expressions such as IL-6, CD21 and CD23, which believe to associate with pathogenesis of this virus. However, molecular mechanism of K-Rta mediated KSHV reactivation is still elusive. This research proposal, entitled "Comprehensive analysis of KSHV gene expression. h is designed to investigate a gdynamic h picture based on genome-wide analysis of KSHV gene regulation with a focus on K-Rta. Understanding the mechanisms of KSHV gene expression and disruption of latency should greatly aid in the therapy and prevention of this disease. Through the experimental activities in the following two specific aims, we will build a model of the KSHV reactivation process. Results from these experiments will enable the development of a comprehensive program to analyze the transcriptional assembly of viral promoters, and hence, to define the detailed mechanism of viral gene transcription and reactivation. Aim1. Transactivation mechanism(s) of K-Rta. (a) Identification of authentic K-Rta target promoters and the temporal dynamics of K-Rta binding to these sites. (b) Genome-wide map of nucleosome occupancy, acetylation and methylation of the KSHV chromatin during reactivation. Aim2. Effects of cellular cofactor on K-Rta: Mechanism of NF-kappaB mediated K-Rta repression. (a) Interplay between NF-kappaB and RBP-Jkappa on KSHV genome. (b) Virological significance of K-Rta cofactor