Genetic analysis of HIV/SIV and HTLV/STLV in Africa -Elucidation of Their Origins and Evolution

现在已知两个灵长类逆转录病毒组HIV/SIV和HTLV/STLV在遗传上相互关联，构成了一个巨大的病毒超家族。对这两个病毒群的遗传分析和传播方式积累的知识表明，这两个病毒群似乎都在进行人畜共患传播。为了阐明这两种病毒群的起源和进化，我们对艾滋病患者、健康人群和中非（喀麦隆、刚果共和国和刚果民主共和国）的少数民族俾格米人进行了血清调查和系统发育分析。俾格米人的血清阳性率出乎意料地低，如果有病毒的话，根据隔离者的基因数据判断，被认为是从邻近的班图居民那里传播的。对来自艾滋病患者的HIV-1的详细遗传分析表明，病毒基因组不仅高度多样化，而且经常嵌合，这意味着基因组大多是重组形式。通过对各种猴种的调查，我们首先从刚果民主共和国捕获的黑白眉猴中分离出一种新的SIV。该病毒（SIVblm）的系统发育位置非常独特，有趣的是，其pol基因组区域（RnaseH）的一部分在遗传上与最古老的HIV - 1毒株之一蚂蚁毒株非常接近，这表明现在的HIV - 1基因组可能是马赛克的，其部分起源可能来自这种猴子物种。

The two primate retrovirus groups, HIV/SIV and HTLV/STLV, are now known to be genetically related each other and constitute a huge viral superfamily. Accumulated knowledges on the genetical analyses and the way of transmission of these two viral groups indicated that both groups appear to have been transmitting zoonotically. To elucidate the origins and evolution of these two virus groups, we conducted serosurveys and phylogenetic analyses of these viruses among AIDS patients, healthy persons, and Pygmy people, an ethnic minority in Central Africa (Cameroon, Republic of Congo, and Democratic Republic of Congo).Seroprevalece of Pygmies was unexpectedly low, and the viruses, if any, were considered to have been transmitted from neighboring Bantu residents judged from genetic data of the isolated ones. Detailed genetic analyses of HIV-1 from AIDS patients have revealed that the viral genomes are not only highly diversified but also frequently mosaic, which means that the genomes are mostly recombinant forms. From the survey among various monkey species, we firstly isolated a new SIV from black mangabeys captured in Democratic Republic of Congo. The phylogenetic position of this virus (SIVblm) is very unique, and interestingly a part of its pol genomic region (RnaseH) is genetically very close to that of the Ant strain, one of the oldest HIV 1 strain, suggesting that the genome of present HIV 1 might be mosaic and its origin is partly from this monkey species.