TRANSIENT VIREMIA FOLLOWING LOW DOSE INTRAVAGINAL INOCULATION OF SIV

意义一些HIV血清阴性的人，暴露在 病毒通过高危行为，感染水平较低，但已 没有产生发出感染信号的抗体。这 观察结果仍然存在争议。SIV/猴子模型可以帮助 了解无症状或潜伏的艾滋病毒感染是如何建立的。 目的证实SIV潜伏感染的假设 是在短暂的病毒感染的猴子身上建立的。结果瞬变 经阴道接种SIV后的病毒血症的特征是 仅在最初几周从PBMC间歇性分离病毒 由于缺乏对SIV抗原的血清转换。瞬变事件的发生率 病毒血症很常见，在53例经阴道接种的患者中有29例出现病毒血症。 猴子，通常在那些猴子身上接种1倍或10倍以上的疫苗 稀释挑战病毒库。一只猴子，20563岁，有 在一年多的时间里一直是SIV培养阴性，自发地成为 再次感染病毒，这种动物又在1.5年后进步到 患上猿猴艾滋病。在对剩余的一过性病毒进行尸检时 猴子，没有从淋巴组织中分离出传染性病毒 生殖器粘膜。然而，SIV可通过敏感的套式PCR检测到 在接受测试的10只猴子中，有10只的PBMC和/或淋巴组织中。在……里面 此外，通过RT-PCR在一些组织中检测到病毒RNA。 SIV-PCR阳性的10只动物中有4只。免疫应答 一过性病毒血症猴的SIV的特征是非常弱 只有在少数猴子身上才能检测到抗体反应 化学发光增强，细胞毒性T淋巴细胞反应弱3例 接受测试的5只动物中，淋巴细胞对SIV的增殖反应 大多数动物体内的蛋白质。未来的方向是 一过性病毒感染猴体内SIV产生性感染的再激活 通过药物或免疫干预，并确定 SIV毒力在接种SIV后恢复 幼稚的猴子有传染性的血浆。SIV；发病机制

Significance Some HIV-seronegative individuals, exposed to the virus through high-riskbehavior, were infected at a low level but had not developed the antibodies that signal the infection. This observation remains controversial. The SIV/monkey model can help to understand how silent or latent HIV infection is established. Objectives To confirm the hypothesis that a latent infection with SIV is established in transiently viremic monkeys. Results Transient viremia following intravaginal inoculation of SIV is characterized by intermittent virus isolation from PBMC only during the first weeks and by lack of seroconversion to SIV antigen. The incidence of transient viremia was common, occurring in 29 of 53 vaginally inoculated monkeys, usually in those monkeys inoculated with 1 or more ten-fold dilution of the challenge virus stock. One monkey, 20563, that had been SIV culture - negative for more than 1 yr, spontaneously became viremic again and this animal progressed over another 1.5 yrs to develop simian AIDS. At necropsy of the remaining transiently viremic monkeys, no infectious virus was isolated from lymphoid tissues or genital mucosa. However, SIV was detectable by sensitive, nested PCR in the PBMC and /or lymphoid tissues of 10 of 10 monkeys tested. In addition, viral RNA was detected by RT-PCR in some of the tissues from 4 of the 10 animals that were SIV-PCR positive. Immune responses to SIV in transiently viremic monkeys were characterized by very weak antibody responses detectable in a minority of monkeys only with enhanced chemiluminescence, weak cytotoxic T lymphocyte responses in 3 of 5 animals tested and lymphocyte proliferative responses to SIV proteins in a majority of the animals. Future Directions To reactivate SIV productive infection in transiently viremic monkeys with pharmacologic or immunologic interventions, and to determine the virulence of SIV recovered after reactivation by the inoculation of naive monkeys with infectious plasma. KEYWORDS SIV, pathogenesis