Serological survey and virus isolation of simian T‐cell leukemia/T‐lymphotropic virus type I (STLV‐I) in non‐human primates in their native countries

Abstract

Infection with a simian retrovirus (STLV-I) closely related to human T-lymphotropic virus type I (HTLV-I) was investigated in non-human primates living in their native countries in Africa and Asia. Serum antibodies cross-reacting with HTLV-I antigens were detected in 85 of 567 non-human primates of 30 species. Seropositive animals were found among African green monkeys, olive baboons, Sykes' monkeys, mandrills and patas monkeys in several countries in Africa, and cynomolgus monkeys, Celebes macaques and siamangs in Indonesia. The frequency of seropositivity was much higher in adult than in young African green monkeys, cynomolgus monkeys and Celebes macaques. STLV-Is were isolated by establishing II lines of virus-producing lymphoid cells in the presence of interleukin-2 from 5 species of seropositive non-human primates, i.e. the African green monkey, Sykes' monkey, Celebes macaque, cynomolgus monkey and siamang. All these cell lines had T-cell markers and Tac antigen, and the cell lines from the African green monkey and Sykes' monkeys were Leu2a+ while those from other species were Leu3a+. These cell lines expressed viral antigens reacting with human sera from adult T-cell leukemia (ATL) patients and monoclonal antibodies (MAbs) against p19 and p24 of HTLV-I core proteins, and produced virus particles having RNA-dependent DNA polymerase activity. Cellular DNAs from these cell lines contained provirus sequences homologous to HTLV-I, shown by Southern blot hybridization. The restriction patterns of these provirus genomes were different from those of HTLV-I and were also dissimilar in the different species.

Cellular Immune Responses against Simian T-Lymphotropic Virus Type 1 Target Tax in Infected Baboons

“…In STLV-1-infected macaques (Macaca tonkeana) and mandrills (Mandrillus sphinx), investigators have described the clonal proliferation of STLV-1-infected cells and preferential infection of CD4 ϩ T cells (35,36). Interestingly, there is a high frequency of STLV-1 seropositivity in wild and captive baboons (37)(38)(39)(40)(41). Phylogenetic analyses of STLV-1 sequences from wild-caught chacma baboons (Papio ursinus) and olive baboons (Papio anubis) suggest cross-species transmissions of STLV-1 in the wild (30,41,42).…”

Divergent Simian T-Cell Lymphotropic Virus Type 3 (STLV-3) in Wild-Caught Papio hamadryas papio from Senegal: Widespread Distribution of STLV-3 in Africa

“…Nevertheless, their origin and evolutionary relationship, as well as their modes of dissemination, are still unclear and a matter of discussion (2,4,10,26,29). While STLV-1 has been detected and characterized in many different African and Asian monkey and ape species (Miyoshi et al,letter;3,7,8,(11)(12)(13)(14)(15)(16)(18)(19)(20)(22)(23)(24)(25)27,(37)(38)(39)(40)(41), including several isolates from wild-caught animals, STLV-2 has been found only in two colonies of bonobos (Pan paniscus) kept either in a zoo (33) or in a primate center colony (5). As for STLV-3, only one strain of its type was known until 2001.…”

Molecular Epidemiology of Simian T-Cell Lymphotropic Virus Type 1 in Wild and Captive Sooty Mangabeys

“…HTLV-2 is not yet associated with a disease, although links to neurologic disorders have been reported (16,22,35). STLV-1 is found as a natural infection in over 20 species of nonhuman primates of African and Asian origin (6,17,18,25,40,46). This virus also causes a long-standing chronic infection that, similar to its human counterpart, may progress to disease; however, only a few cases of STLV-1-associated disease following natural infection have been documented (32,49,50).…”

“…Therefore, characterizing STLV-1 diversity in different species of nonhuman primates and correlating this characterization with HTLV diversity may provide significant information on the mechanism of HTLV emergence. To date, studies of STLV-1 diversity in different species of monkeys and apes in Central Africa have demonstrated the presence of specific STLV-1 variants in several subspecies of baboons (Papio hamadryas, Papio anubis, and Papio doguera) (25,28,43), gelada baboons (Theropithecus gelada) (53), swamp monkeys (Allenopithecus nigroviridis) (28), grivet monkeys (Cercopithecus aethiops aethiops) (18,28), tantalus monkeys (Cercopithecus aethiops tantalus), crested mona monkeys (Cercopithecus mona pogonias) (28), Syke's monkeys (Cercopithecus albogularis) (43), patas monkeys (Erythrocebus patas) (43), mandrills (Mandrillus sphinx) (26,36), SMs (Cercocebus atys) (8,43), agile mangabeys (Cercocebus agilis) (37), chimpanzees (Pan troglodytes) (19,38,39), and gorillas (Gorilla gorilla) (38). Interestingly, although SMs are the documented source of HIV-2 (4), information concerning STLV diversity and prevalence in SMs in their natural habitats has not been reported.…”