Human herpesvirus 8 (the Kaposi sarcoma-associated herpesvirus) contributes causally to the development of Karopsi sarcoma and pleural effusion lymphomas. It is a member of the gamma-2 or rhadinovirus subfamily of herpesviruses. Members of this herpesvirus subfamily are quite consistently associated with the ability to cause lymphoma in natural or experimental hosts. Rhesus monkey rhadinovirus (RRV) is a very close relative of KSHV (HHV-8). The recently published sequence for RRV shows gene for gene correspondence with KSHV in the mast majority of genes. There are two major difficulties for the continued study of KSHV. 1) It ha snot been possible to grow the virus lytically in cell culture. Consequently, study of the lytical cycle and development of a genetic system for the study of gene knockouts and mutant and recombinant forms of virus have been difficult or impossible. 2) There is no animal model that uses KSHV for infection. RRV can be grown lytically in cell culture and used to infect seronegative rhesus monkeys experimentally. In the proposed studies, the sites of primary RRV replication in the oral cavity will be examined following oral and intravenous infection of rhesus monkeys by RRV. Cell types supporting RRV replication in the oral cavity during primary injection of rhesus monkeys by RRV. Cell types supporting RRV replication in the oral cavity during primary infection will be determined by in situ hybridization and immunohistochemical staining procedures and by use of an RRV strain that expresses green fluorescent protein. The extent to which RRV can be detected in saliva during primary infection and during persistence will be analyzed and the sites of RRV persistence in the oral cavity will be determined. A genetic system will be developed that will allow us to construct and study gene knockout, mutant and recombinant forms of RRV. The combinations of individual glycoprotein genes to infection, tropism, and persistence will be analyzed. These studies will facilitate our understanding of the contribution of individual genes to viral infection, shedding, and persistence.
