RESTRICTED EXPRESSION OF KAPOSI SARCOMA-ASSOCIATED HERPESVIRUS (HUMANHERPESVIRUS-8) GENES IN KAPOSI-SARCOMA

Kaposi sarcoma (KS) is the leading neoplasm of HIV-infected patients a nd is also found in several HIV-negative populations. Recently, DNA se quences from a novel herpesvirus, termed KS-associated herpesvirus (KS HV), or human herpesvirus 8 (HHV-8) have been identified within KS tis sue from both HIV-positive and HIV-negative cases; infection with this agent has been proposed as a possible factor in the etiology or patho genesis of the tumor. Here we have examined the pattern of KSHV/HHV-8 gene expression in KS and find it to be highly restricted, We identify and characterize two small transcripts that represent the bulk of the virus-specific RNA transcribed from over 120 kb of the KSHV genome In Infected cells, One transcript is predicted to encode a small membran e protein; the other is an unusual polyadenylylated RNA that accumulat es in the nucleus to high copy number, This pattern of viral gene expr ession suggests that most infected cells in KS are latently infected, with lytic viral replication likely restricted to a much smaller subpo pulation of cells, These findings have implications for the therapeuti c utility of currently available antiviral drugs targeted against the lytic replication cycle.