Two Distinct Gamma-2 Herpesviruses in African Green Monkeys: a Second Gamma-2 Herpesvirus Lineage among Old World Primates?

Primate gamma-2 herpesviruses (rhadinoviruses) have so far been found in humans (Kaposi's sarcoma-associated herpesvirus [KSHV], also called human herpesvirus 8), macaques (Macaca spp.) (rhesus rhadinovirus [RRV] and retroperitoneal fibromatosis herpesvirus [RFHV]), squirrel monkeys (Saimiri sciureus) (herpesvirus saimiri), and spider monkeys (Ateles spp.) (herpesvirus ateles). Using serological screening and degenerate consensus primer PCR for the viral DNA polymerase gene, we have detected sequences from two distinct gamma-2 herpesviruses, termed Chlorocebus rhadinovirus 1 (ChRV1) and ChRV2, in African green monkeys. ChRV1 is more closely related to KSHV and RFHV, whereas ChRV2 is closest to RRV. Our findings suggest the existence of two distinct rhadinovirus lineages, represented by the KSHV/RFHV/ChRV1 group and the RRV/ChRV2 group, respectively, in at least two Old World monkey species. Antibodies to members of the RRV/ChRV2 lineage may cross-react in an immunofluorescence assay for early and late KSHV antigens.