REACTIVITIES OF HUMAN SERA WITH HUMAN HERPESVIRUS-8-INFECTED BCBL-1 CELLS AND IDENTIFICATION OF HHV-8-SPECIFIC PROTEINS AND GLYCOPROTEINS AND THE ENCODING CDNAS

The reactivates of human sera with uninduced and phorbol eater (TPA)-i nduced human herpesvirus-8 (HHV-8)-infected BCBL-1 cells were examined by immunofluorescence assay (IFA) and by radioimmunoprecipitation rea ctions (RIP). The seroprevalence of HHV-8 infections is low in the Uni ted Stales general population and only low levels of HHV-8 antibodies were detected in the seropositive sera. In contrast, high levels of an tibodies against HHV-8 lyric and latent antigens were detected by IFA in the sera from HIV+ Kaposi's sarcoma (KS)-positive individuals. Thes e sera recognized several proteins and glycoproteins from BCBL-1 cells in RIP reactions. Two types of antibody responses were detected in th e sera from HIV+ KS- homosexual men. In majority of the sera with and without detectable HHV-8 DNA in the peripheral blood mononuclear cells (PBMC), significantly low levels of HHV-8 antibodies were detected by IFA. These sera recognized only a subset of HHV-8 proteins and glycop roteins in RIP reactions. In contrast, in a subgroup of sera from HIV KS- homosexual men, higher levels of IFA antibodies against HHV-8 lyt ic and latent antigens were detected. These sera also recognized sever al viral proteins and glycoproteins in RIP reactions. These results su ggest that antibody response profiles to HHV-8 infection vary signific antly and serologic assays to detect antibody responses to a panel of bath lyric and latent antibodies may he required for maximum sensitivi ty. Screening of a cDNA library from TPA-induced BCBL-1 cells with an HIV+ KS+ serum identified cDNAs encoding 12 HHV-8 proteins. Further ch aracterization of these HHV-8 proteins would define the HHV-8 antigens useful for seroepidemiological studies and in discriminating lyric, l atent, past, and/or reactivation infections. (C) 1998 Academic Press.