Mosaic genome structure of simian immunodeficiency virus from west African green monkeys.

To better understand which factors govern the levels of viral loads in early lentiviral infections of primates, we developed a model that allows distinguishing between the influences of host and viral factors on viremia. Herein we report that two species of African green monkeys (Chlorocebus sabaeus and C. pygerythrus) infected with their respective wild-type simian immunodeficiency virus SIVagm viruses (SIVagm.sab92018 and SIVagm. ver644) consistently showed reproducible differences in viremia during primary infection but not at later stages of infection. Cross-infections of SIVagm.sab92018 and SIVagm.ver644 into, respectively, C. pygerythrus and C. sabaeus revealed that the dynamics of viral replication during primary infection were dependent on the viral strain used for the infection but not on the host. Hence, the kinetics of SIVagm.sab92018 and SIVagm.ver644 were similar in both sabaeus and vervet animals, indicating that the difference in viremia levels between the two groups during the early phase of infection was not associated with the host. Coreceptor usage for these two strains showed a larger coreceptor repertoire for SIVagm.sab92018, which is able to efficiently use CXCR4 in addition to CCR5, than for SIVagm.ver644, which showed a classical CCR5 coreceptor usage pattern. These differences could not be explained by different charges of the V3 loop for SIVagm.sab92018 and for SIVagm. ver644. In conclusion, our study showed that the extent of virus replication during the primary infection is primarily dependent on viral determinants.

Section: Discussionmentioning

confidence: 98%

Section: Animals and Infectionsmentioning

confidence: 99%

mentioning

confidence: 99%

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Impact of Viral Factors on Very Early In Vivo Replication Profiles in Simian Immunodeficiency Virus SIVagm-Infected African Green Monkeys

Pandrea

Kornfeld

Ploquin

et al. 2005

“…On the one hand, phylogenetic relationships among these viruses indicate that some SIV lineages have coevolved with their hosts, as is the case for SIVagm in African green monkeys (1,16,20) and SIVlhoest and SIVsun within the Cercopithecus lhoesti superspecies (3). On the other hand, there are also multiple examples of cross-species transmissions from simians to humans and between different simian species.…”

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confidence: 99%

Identification of a New Simian Immunodeficiency Virus Lineage with a vpu Gene Present among Different Cercopithecus Monkeys ( C. mona , C. cephus , and C. nictitans ) from Cameroon

Courgnaud

Abela²,

Pourrut³

et al. 2003

During a large serosurvey of wild-caught primates from Cameroon, we found 2 mona monkeys (Cercopithecus mona) out of 8 and 47 mustached monkeys (Cercopithecus cephus) out of 302 with human immunodeficiency virus (HIV)-simian immunodeficiency virus (SIV) cross-reactive antibodies. In this report, we describe the full-length genome sequences of two novel SIVs, designated SIVmon-99CMCML1 and SIVmus-01CM1085, isolated from one mona (CML1) and one mustached (1085) monkey, respectively. Interestingly, these viruses displayed the same genetic organization (i.e., presence of a vpu homologue) as members of the SIVcpz-HIV type 1 lineage and SIVgsn isolated from greater spot-nosed monkeys (Cercopithecus nictitans). Phylogenetic analyses of SIVmon and SIVmus revealed that these viruses were genetically distinct from other known primate lentiviruses but were more closely related to SIVgsn all across their genomes, thus forming a monophyletic lineage within the primate lentivirus family, which we designated the SIVgsn lineage. Interestingly, mona, mustached, and greater spot-nosed monkeys are phylogenetically related species belonging to three different groups of the genus Cercopithecus, the C. mona, C. cephus, and Cercopithecus mitis groups, respectively. The presence of new viruses closely related to SIVgsn in two other species reinforces the hypothesis that a recombination event between ancestral SIVs from the family Cercopithecinae is the origin of the present SIVcpz that is widespread among the chimpanzee population.

“…Briefly, SIV isolates segregate phylogenetically, based upon their species of origin, into at least five lineages represented by SIVsm, SIVagm, SIVsyk, SIVlhoest (9,26), and SIVcpz with a number of additional novel strains from other primates recently characterized (12,18). The SIVagm lineage consists of four distinct subtypes that cluster depending upon the species of AGM from which they were isolated, i.e., grivets (Chlorocebus aethiops; SIVagm/gri [14,29]), vervets (Chlorocebus pygerythrus; SIVagm/ver [1,4,5,15,20,29]), sabaeus monkeys (Chlorocebus sabaeus; SIVagm/sab [1][2][3]28]), and tantalus monkeys (Chlorocebus tantalus; SIVagm/tan [22,33]). …”

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confidence: 99%

Wide Range of Viral Load in Healthy African Green Monkeys Naturally Infected with Simian Immunodeficiency Virus

Goldstein

Ourmanov

Brown

et al. 2000

123

The distribution and levels of simian immunodeficiency virus (SIV) in tissues and plasma were assessed in naturally infected African green monkeys (AGM) of the vervet subspecies (Chlorocebus pygerythrus) by limitingdilution coculture, quantitative PCR for viral DNA and RNA, and in situ hybridization for SIV expression in tissues. A wide range of SIV RNA levels in plasma was observed among these animals (<1,000 to 800,000 copies per ml), and the levels appeared to be stable over long periods of time. The relative numbers of SIV-expressing cells in tissues of two monkeys correlated with the extent of plasma viremia. SIV expression was observed in lymphoid tissues and was not associated with immunopathology. Virus-expressing cells were observed in the lamina propria and lymphoid tissue of the gastrointestinal tract, as well as within alveolar macrophages in the lung tissue of one AGM. The range of plasma viremia in naturally infected AGM was greater than that reported in naturally infected sooty mangabeys. However, the degree of viremia in some AGM was similar to that observed during progression to AIDS in human immunodeficiency virus-infected individuals. Therefore, containment of viremia is an unlikely explanation for the lack of pathogenicity of SIVagm in its natural host species, AGM. Human immunodeficiency virus type 1 (HIV-1) is a member of a large family of nonhuman primate lentiviruses which have been designated simian immunodeficiency viruses (SIVs). At the present time, SIVs from at least seven African monkey species have been identified and molecularly characterized. The genetic relationships among five of these SIV strains isolated from sooty mangabey monkeys (Cercocebus atys; SIVsm), mandrills (Mandrillus sphinx; SIVmnd), Sykes monkeys (Cercopithecus albogularis mitis; SIVsyk), African green monkeys, (AGM; Chlorocebus spp.; SIVagm), and chimpanzees (Pan troglodytes; SIVcpz) have been reviewed previously (23,25,44). Briefly, SIV isolates segregate phylogenetically, based upon their species of origin, into at least five lineages represented by SIVsm, SIVagm, SIVsyk, SIVlhoest (9,26), and SIVcpz with a number of additional novel strains from other primates recently characterized (12,18). The SIVagm lineage consists of four distinct subtypes that cluster depending upon the species of AGM from which they were isolated, i.e