Department of Pathology, Emory University, Atlanta, GA 30329, USA.
Proc Natl Acad Sci U S A. 2011 Nov 15;108(46):E1156-63. doi: 10.1073/pnas.1103764108. Epub 2011 Nov 7.
The predominant mode of HIV-1 infection is heterosexual transmission, where a genetic bottleneck is imposed on the virus quasispecies. To probe whether limited genetic diversity in the genital tract (GT) of the transmitting partner drives this bottleneck, viral envelope sequences from the blood and genital fluids of eight transmission pairs from Rwanda and Zambia were analyzed. The chronically infected transmitting partner's virus population was heterogeneous with distinct genital subpopulations, and the virus populations within the GT of two of four women sampled longitudinally exhibited evidence of stability over time intervals on the order of weeks to months. Surprisingly, the transmitted founder variant was not derived from the predominant GT subpopulations. Rather, in each case, the transmitting variant was phylogenetically distinct from the sampled locally replicating population. Although the exact distribution of the virus population present in the GT at the time of transmission cannot be unambiguously defined in these human studies, it is unlikely, based on these data, that the transmission bottleneck is driven in every case by limited viral diversity in the donor GT or that HIV transmission is solely a stochastic event.
HIV-1 的主要感染模式是异性传播，在这种传播方式中，病毒准种会受到遗传瓶颈的限制。为了探究传播伴侣生殖道（GT）中有限的遗传多样性是否会导致这种瓶颈，对来自卢旺达和赞比亚的 8 对传播对的血液和生殖道液中的病毒包膜序列进行了分析。慢性感染的传播伴侣的病毒群体具有异质性，存在明显的生殖道亚群，并且在对四名女性中的两名进行的纵向采样中，GT 内的病毒群体在数周到数月的时间间隔内表现出稳定的证据。令人惊讶的是，传播的创始变体并非源自主要的 GT 亚群。相反，在每种情况下，传播变体在系统发育上与采样的局部复制群体都不同。尽管在这些人类研究中，无法明确界定传播时 GT 中存在的病毒群体的确切分布，但根据这些数据，传播瓶颈不太可能在每种情况下都由供体 GT 中有限的病毒多样性驱动，或者 HIV 传播仅是一种随机事件。
