Evaluation of defective HIV as factors for AIDS pathogenesis

感染人类免疫缺陷病毒1型(HIV-1)会在大约10年内导致艾滋病。艾滋病的发病机制有几个特点：1)疾病的临床分期与HIV-1载量显著相关，2)有效的抗逆转录病毒药物能显著降低血浆病毒血症，3)抗HIV-1药物对来自短寿命高产感染细胞的HIV-1有效，但对来自潜伏病毒库的HIV-1不是那么有效。我们已经发现，伴随着vif、vpr和/或vPU等辅助基因突变的HIV-1感染可以在人类T细胞系MT-4中建立持续或潜伏的感染。在野生型HIV-1的连续传代过程中，类似的突变自然发生，并建立了潜伏感染。相反，带有nef突变的HIV-1没有建立持续感染，这表明nef基因是HIV-1持续感染所必需的。我们还发现，可溶性Nef蛋白具有从…重新激活HIV-1的功能更多延迟。此外，我们还发现，HIV-1病毒粒子的吸附可以产生效应细胞，诱导旁观者未感染的T细胞凋亡。这些现象似乎对理解HIV-1诱导的发病机制很重要。另一方面，在包括泰国在内的东南亚地区传播的HIV-1是E分支。在这次国际联合研究项目中，我们进一步表征了泰国HIV-1携带者的HIV-1分支E。泰国E型HIV-1病毒的全长序列于1996年首次报道。该序列的E病毒是从一名21岁的泰国男子身上分离出来的，他于1990年被确定为HIV-1血清阳性。然而，我们发现，根据报道的序列制备的引物进行聚合酶链式反应，很难在最近从泰国HIV-1 E-阳性无症状携带者的大部分血液样本中扩增出E-HIV-1，这表明目前传播的泰国E-HIV-1存在先进的突变。根据A分支序列，我们可以从2个B分支阳性和2个E阳性携带者的4个分离株中扩增出泰国HIV-1的NEF序列。结果显示，泰国两株HIV-1 E分支间的遗传变异为6.43%，B分支与E分支间的遗传变异为-13%。事实上，用B分支Nef蛋白免疫制备的13株鼠单抗与这些E分支HIV-1分离株无交叉反应。另一方面，我们证实，泰国E分支感染携带者的血液T细胞中也观察到了旁观者T细胞的凋亡，其机制与我们通过B分支HIV-颗粒吸附体外研究中观察到的机制相似。较少

Infection with human immunodeficiency virus type 1 (HIV-1) leads to AIDS within about 10 years. There are several features ascribed to the AIDS pathogenesis : 1) clinical staging of the disease is significantly correlated with HIV-1 load, 2) potent antiretroviral drugs produce a dramatic drop in plasma viremia, and 3) the anti-HIV-1 drugs are effective for HIV-1 derived from short-lived productively infected cells, but not so effective for HIV-1 derived from latent reservoirs. We have found that infection by HIV-1 with mutations at accessory genes such as vif, vpr, and/or vpu can establish persistent or latent infection in human T-cell line, MT-4. During serial passage of wild-type HIV-1, similar mutations naturally occurred and established latent infection. In contrast, HIV-1 with mutation at nef did not establish persistent infection, indicating that nef gene is necessary for persistent infection of HIV-1. We also found that soluble Nef protein has a function to reactivate HIV-1 from … More latency. In additon, we have found that HIV-1 virion adsorption can generate effector cells to induce apoptosis in bystander uninfected T-cells. These phenomena seem to be important to understand HIV-1-induced pathogenesis. However, all these results were obatined only by characterization of HIV-1 clade B.On the other hand, the HIV-1 spreading in South Eastern Asia including Thailand is clade E.In this international joint research project, we have further characterized HIV-1 clade E from Thai HIV-1 carriers. The full-length sequence of Thai E HIV-1 was first reported in 1996. The E virus for the sequence was isolated from a 21-year-old Thai man, who was determined to be seropositive for HIV-1 at 1990. However, we found that the polymerase chain reaction with primers prepared according to the reported sequence was difficult to amplify the clade E HIV-1 in most of the blood samples recently collected from HIV-1 clade E-seropositive asymptomatic carriers in Thailand, indicating advanced mutations in currently spreading Thai E HIV-1. We could amplify Thai HIV-1 sequences at nef from four isolates of two clade B-seropositive and two E-seropositive carriers using primers according to clade A sequence. The results showed 6.43% genetic variability between two HIV-1 clade E isolates and -13% genetic variability between clade B and E HIV-1 in Thailand. In fact, 13 murine monoclonal antibodies prepared by immunization with clade B Nef protein did not cross-react with these clade E HIV-1 isolates. On th other hand, we confirmed that apoptosis in bystander T-cells was also observed in the blood T-cells prepared from Thai clade E infected carriers by similar mechanism as we have observed by in vitro studies using clade B HIV- particle adsorption. Less