title: High prevalence of simian T-lymphotropic virus type L in wild ethiopian baboons.
abstract: Simian T-cell leukemia viruses (STLVs) are the simian counterparts of human T-cell leukemia viruses (HTLVs). A novel, divergent type of STLV (STLV-L) from captive baboons was reported in 1994, but its natural prevalence remained unclear. We investigated the prevalence of STLV-L in 519 blood samples from wild-living nonhuman primates in Ethiopia. Seropositive monkeys having cross-reactive antibodies against HTLV were found among 22 out of 40 hamadryas baboons, 8 of 96 anubis baboons, 24 of 50 baboons that are hybrids between hamadryas and anubis baboons, and 41 of 177 grivet monkeys, but not in 156 gelada baboons. A Western blotting assay showed that sera obtained from seropositive hamadryas and hybrid baboons exhibited STLV-L-like reactivity. A PCR assay successfully amplified STLV sequences, which were subsequently sequenced and confirmed as being closely related to STLV-L. Surprisingly, further PCR showed that nearly half of the hamadryas (20 out of 40) and hybrid (19 out of 50) baboons had STLV-L DNA sequences. In contrast, most of the seropositive anubis baboons and grivet monkeys carried typical STLV-1 but not STLV-L. These observations demonstrate that STLV-L naturally prevails among hamadryas and hybrid baboons at significantly high rates. STLV-1 and -2, the close relative of STLV-L, are believed to have jumped across simian-human barriers, which resulted in widespread infection of HTLV-1 and -2. Further studies are required to know if STLV-L is spreading into human populations.
authors.affiliation: Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Taichiro
authors.initials: T
authors.lastname: Takemura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamashita
authors.forename: Makoto K
authors.initials: MK
authors.lastname: Shimada
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Ohkura
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shotake
authors.forename: Mikio
authors.initials: M
authors.lastname: Ikeda
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miura
authors.forename: Masanori
authors.initials: M
authors.lastname: Hayami
mesh_terms: D000818:Animals; D000835:Animals, Wild; D000914:Antibodies, Viral / Q000097:blood*; D001483:Base Sequence; D003429:Cross Reactions; D006800:Deltaretrovirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D015481:HTLV-I Antibodies / Q000097:blood; D015482:HTLV-II Antibodies / Q000097:blood; D006801:Humans; D008969:Molecular Sequence Data; D008992:Monkey Diseases / Q000453:epidemiology* / Q000821:virology; D010215:Papio; D010802:Phylogeny; D015995:Prevalence; D017422:Sequence Analysis, DNA; D015303:Simian T-lymphotropic virus 1 / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000914:Antibodies, Viral; D015481:HTLV-I Antibodies; D015482:HTLV-II Antibodies