Berry N, Ariyoshi K, Jaffar S, Sabally S, Corrah T, Tedder R, Whittle H
Department of Virology, Windeyer Institute of Medical Sciences, University College London Medical School, U.K.
J Hum Virol. 1998 Nov-Dec;1(7):457-68.
To elucidate why the virulence of HIV-1 and HIV-2 infections differ in West African populations.
STUDY DESIGN/METHOD: Peripheral blood plasma virion RNA and cellular proviral DNA levels were measured in a cross-section of 59 HIV-1 and 49 HIV-2 singly infected individuals representing all stages of infection in The Gambia, West Africa. Novel reverse transcriptase polymerase chain reaction (RT-PCR) assays specific and sensitive for virus quantification of non-clade B HIV-1 and HIV-2 infections were used.
HIV-1 and HIV-2 proviral and plasma RNA levels were inversely correlated with CD4+ count for both infections with cellular proviral load similar at each stage of infection. Critically, up to three-fourths of HIV-2-infected individuals with high CD4 percentages (> 28%) had undetectable (< 500 copies/mL) levels of peripheral blood HIV-2 RNA in contrast to HIV-1-infected individuals who had readily detectable plasma virus at all stages of infection (P < .0001). Plasma RNA levels were similar in the intermediate and end stages of infection, indicating similar replication potential for both viruses. In the cross-section of HIV-1- and HIV-2-infected patients studied, the data indicate a wider dynamic range of HIV-2 RNA in vivo compared with HIV-1.
Low levels of HIV-2 replication and virion expression characterize individuals with high CD4+ lymphocyte counts, suggesting that a very different dynamic equilibrium exists between virus and host for HIV-2 compared with HIV-1. By analogy with HIV-1, our data implicate a considerably lower turnover of HIV-2 virion RNA in vivo with a markedly reduced production of infectious genomes in individuals during the subclinical phase of infection.
The lower levels of virion expression of HIV-2 infections in vivo are compatible with observed differences in the natural history of HIV-1 and HIV-2 infections, relating to overall differences in the pathogenesis and disease progression of the two infections.
阐明在西非人群中，HIV-1和HIV-2感染的毒力为何不同。
研究设计/方法：在西非冈比亚，对59例HIV-1单感染个体和49例HIV-2单感染个体进行横断面研究，这些个体代表了感染的各个阶段，测量其外周血血浆病毒粒子RNA和细胞前病毒DNA水平。使用了对非B亚型HIV-1和HIV-2感染的病毒定量具有特异性和敏感性的新型逆转录酶聚合酶链反应（RT-PCR）检测方法。
HIV-1和HIV-2的前病毒及血浆RNA水平与两种感染的CD4 +细胞计数均呈负相关，在感染的各个阶段细胞前病毒载量相似。至关重要的是，高达四分之三的CD4百分比高（> 28％）的HIV-2感染个体外周血HIV-2 RNA水平检测不到（<500拷贝/ mL），而HIV-1感染个体在感染的所有阶段血浆病毒都易于检测到（P <.0001）。感染中期和末期的血浆RNA水平相似，表明两种病毒的复制潜力相似。在所研究的HIV-1和HIV-2感染患者的横断面中，数据表明与HIV-1相比，HIV-2在体内的RNA动态范围更广。
CD4 +淋巴细胞计数高的个体具有低水平的HIV-2复制和病毒粒子表达，这表明与HIV-1相比，HIV-2与宿主之间存在非常不同的动态平衡。与HIV-1类似，我们的数据表明，在感染的亚临床阶段，HIV-2病毒粒子RNA在体内的周转相当低，个体中感染性基因组的产生明显减少。
HIV-2感染在体内较低水平的病毒粒子表达与HIV-1和HIV-2感染自然史中观察到的差异相符，这与两种感染在发病机制和疾病进展方面的总体差异有关。
