Two distinct lineages of macaque gamma herpesviruses related to the Kaposi's sarcoma associated herpesvirus

Background: KSHV, Kaposi's sarcoma-associated herpesvirus, is a necessary c ofactor for the development of Kaposi's sarcoma (KS). We have previously re ported KSHV-related DNA sequences in retroperitoneal fibromatosis (RF) tiss ue from two species of macaque. The putative herpesvirus was called RFHV fo r RF-associated herpesvirus. These data suggested that KSHV is a human repr esentative of a larger family of primate herpesviruses. Objective: To ident ify and characterize other members of a putative family of KSHV-related her pesviruses in macaques in order to obtain information on the evolutionary h istory of KSHV infection in humans. Study design: Lymphoid tissue cells and blood leukocytes from rhesus-, cynomolgus- and pigtailed-macaques were tes ted for the presence of unknown herpesviruses using degenerate primer-drive n PCR amplification. The sequences obtained were compared against known her pesvirus sequences. Results: We have identified new herpesvirus DNA sequenc es in each of the three macaque species. Sequence comparisons indicate that these new viruses are most related to each other and form a separate phylo genetic lineage within the gamma herpesviruses. Screening of PBMC from Indo nesian-origin quarantine animals suggests that these viruses (MGV, macaque gamma virus) are species-specific, and highly prevalent in the wild. They a re readily cultured in vivo, and share a common tissue tropism with the pre viously identified RFHV. Conclusions: MGV and RFHV represent two independen t introductions of an ancestral gamma herpesvirus into macaque precursors. (C) 2000 Elsevier Science B.V. All rights reserved.