New Simian Immunodeficiency Virus Infecting De Brazza's Monkeys (
            <i>Cercopithecus neglectus</i>
            ): Evidence for a
            <i>Cercopithecus</i>
            Monkey Virus Clade

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125

Simian immunodeficiency virus of sooty mangabeys (SIVsmm) is recognized as the progenitor of human immunodeficiency virus type 2 (HIV-2) and has been transmitted to humans on multiple occasions, yet the epidemiology and genetic diversity of SIVsmm infection in wild-living populations remain largely unknown.Here, we report the first molecular epidemiological survey of SIVsmm in a community of ϳ120 free-ranging sooty mangabeys in the Taï Forest, Côte d'Ivoire. Fecal samples (n ‫؍‬ 39) were collected from 35 habituated animals (27 females and 8 males) and tested for SIVsmm virion RNA (vRNA). Viral gag (800 bp) and/or env (490 bp) sequences were amplified from 11 different individuals (eight females and three males). Based on the sensitivity of fecal vRNA detection and the numbers of samples analyzed, the prevalence of SIVsmm infection was estimated to be 59% (95% confidence interval, 0.35 to 0.88). Behavioral data collected from this community indicated that SIVsmm infection occurred preferentially in high-ranking females. Phylogenetic analysis of gag and env sequences revealed an extraordinary degree of genetic diversity, including evidence for frequent recombination events in both the recent and distant past. Some sooty mangabeys harbored near-identical viruses (<2% interstrain distance), indicating epidemiologically linked infections. These transmissions were identified by microsatellite analyses to involve both related (mother/daughter) and unrelated individuals, thus providing evidence for vertical and horizontal transmission in the wild. Finally, evolutionary tree analyses revealed significant clustering of the Taï SIVsmm strains with five of the eight recognized groups of HIV-2, including the epidemic groups A and B, thus pointing to a likely geographic origin of these human infections in the eastern part of the sooty mangabey range.

mentioning

confidence: 99%

Simian Immunodeficiency Virus Infection in Free-Ranging Sooty Mangabeys ( Cercocebus atys atys ) from the Taï Forest, Côte d'Ivoire: Implications for the Origin of Epidemic Human Immunodeficiency Virus Type 2

Santiago

Range

Keele

et al. 2005

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“…Simian immunodeficiency viruses (SIVs) are known to naturally infect at least 40 different species of nonhuman primates in Sub-Saharan Africa (9,72). Although each of these primate species harbors a genetically distinct lineage of SIV, phylogenetic evidence indicates that SIVs have crossed species boundaries on numerous occasions in the past (5,6,30,57).…”

mentioning

confidence: 99%

Origin and Biology of Simian Immunodeficiency Virus in Wild-Living Western Gorillas

Takehisa¹,

Kraus²,

Ayouba

et al. 2009

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“…More than 30 different simian immunodeficiency virus (SIV) types naturally infect a variety of African nonhuman primates (NHP) of African origin (3,11). They form at least eight phylogenetic lineages (3,11,20) and have evolved through host-dependent evolution (1,9,27,45,57), cross-species transmissions (12,37,62,65), recombinations (4,10,28,35,36,61), and preferential host switching (17).…”

mentioning

confidence: 99%

Primary Simian Immunodeficiency Virus SIVmnd-2 Infection in Mandrills ( Mandrillus sphinx )

Onanga

Souquière

Makuwa

et al. 2006

Mandrills are the only nonhuman primate (NHP) naturally infected by two types of simian immunodeficiency virus (SIV): SIVmnd-1 and SIVmnd-2. We have already reported that the high SIVmnd-1 replication during primary infection contrasts with only transient changes in CD4؉ and CD8 ؉ cell counts. Since early virus-host interactions predict viral control and disease progression in human immunodeficiency virusinfected patients, we investigated the dynamics of SIVmnd-2 primary infection in mandrills to examine the impact on immune effectors in blood and lymph nodes (LNs). To avoid in vitro strain selection, all mandrills in this study received plasma from SIVmnd-2-infected mandrills. SIVmnd-2 plasma viremia peaked at 10 7 to 10 8 RNA copies/ml between days 7 and 10. This peak was followed in all four monkeys by a decline in virus replication, with a set point level of 10 5 to 10 6 RNA copies/ml at day 42 postinfection (p.i.). Viral DNA load in PBMC and LNs also peaked between days 7 and 10 (10 5 to 10 6 DNA copies/10 6 cells) and stabilized at 10 3 to 10 4 DNA copies/10 6 cells during the chronic phase. Anti-SIVmnd-2 antibodies were detected starting from days 28 to 32. A transitory decline of CD3 ؉ CD4 ؉ cells in the LNs occurred in animals with high peak VLs. CD4؉ and CD8 ؉ T-cell activation in blood and LNs was noted between days 5 and 17 p.i., surrounding the peak of viral replication. This was most significant in the LNs. Activation markers then returned to preinfection values despite continuous and active viral replication during the chronic infection. The dynamics of SIVmnd-2 infection in mandrills showed a pattern similar to that of SIVmnd-1 infection. This might be a general feature of nonpathogenic SIV natural African NHP models.