INTERACTIONS OF HUMAN RETROVIRUSES WITH HEMATOPOIETIC AND ADHERENT CELLS

本节的总体目标是更好地了解 宿主细胞和其他辅助因素对人类逆转录病毒复制的影响。在……里面 尤其是单核/巨噬细胞，它是HIV-1感染的宿主 艾滋病患者，被证明能够限制HIV-1的表达。在……里面 Thp-1，单核细胞系，两类限制性HIV-1 可见：1)低水平表达；2)无表达(潜伏期)。 5-氮胞苷后潜伏感染细胞产生感染性病毒 曝光。相反，内毒素和几种细胞因子可以增加病毒 限制细胞产生，但不能激活潜伏感染 细胞。因此，艾滋病毒表达的限制状态和潜伏状态 可能通过不同的机制发生在单核细胞中。在受限制的艾滋病毒中- 1表达THP-1，细胞中不存在DNA结合蛋白复合体 HIV-1增强剂的产生明显减少 病毒核糖核酸。这种结合的缺失局限于核因子-kappaB HIV增强子的区域，其中65+50kD的NF-kappaB异源二聚体是 优先输掉。纯化的核因子-kappaB蛋白在核内的添加 从表达受限的细胞中提取的物质可以恢复这种结合。 此外，用脱氧胆酸钠处理这些核提取液 恢复了异二聚体结合，提示一种特异性的核因子抑制物- ~B存在于这些细胞中。因此，65+50kD的结合 HIV-1增强子的异源二聚体可以在 单核细胞。对潜伏感染THP-1的研究表明，这些细胞 可通过与ConA-A共培养诱导表达感染性病毒 激活的T细胞，从正常的、HIV阴性的捐赠者身上分离出来。新鲜的 从无症状血清阳性个体分离贴壁单核细胞 经检查发现含有潜伏的艾滋病毒。在这些细胞共培养后 单核细胞与ConA激活的T细胞来自HIV阴性的正常捐赠者， 这些潜伏的单核细胞培养物表达病毒。艾滋病病毒产生者 激活的潜伏单核细胞感染T细胞并可导致病毒诱导 病理学。这些结果表明受感染的单核细胞 在病毒持续和传播过程中产生很少或根本没有病毒 尤其是那些多年无症状的感染者。 在发展为明显的艾滋病之前。

The overall goal of this section is to better understand the effects of the host cell and other co-factors on human retroviral replication. In particular, the monocyte/macrophage, a reservoir of HIV-1 infection in AIDS patients, was shown to be able to restrict HIV-1 expression. In THP-1, a monocytoid cell line, two classes of restricted HIV-1 expression were seen: 1) low-level and 2) no expression (latent). Latently infected cells made infectious virus after 5-azacytidine exposure. In contrast, LPS and several cytokines could increase viral production in restricted cells but could not activate latently infected cells. Thus, both restricted and latent states of HIV expression probably occur in monocytes by different mechanisms. In restricted HIV- 1 expressing THP-1, the absence of a DNA binding protein complex in the HIV-1 enhancer was seen concomitant with the production of markedly less viral RNA. This absence of binding was localized to the NF-kappaB region of the HIV enhancer with the 65+50 kD NF-kappaB heterodimer being preferentially lost. Addition of purified NF-kappaB protein to nuclear extracts from cells with restricted expression restores this binding. Also, treatment of these nuclear extracts with sodium deoxycholate restored heterodimer binding suggesting that a specific inhibitor of NF- ~B was present in these cells. Thus, the binding of 65+50 kD heterodimer to the HIV-1 enhancer can be negatively regulated in monocytes. Studies of latently infected THP-1 showed that these cells could be induced to express infectious virus by coculture with Con A- activated T cells, isolated from normal, HIV negative donors. Freshly isolated adherent monocytes from asymptomatic seropositive individuals were examined and found to contain latent HIV. After coculture of these monocytes with Con A-activated T cells from HIV negative normal donors, these latent monocyte cultures expressed virus. HIV produced by activated latent monocytes infects T cells and can lead to viral-induced pathology. These results suggest a role for infected monocytes producing little or no virus in viral persistence and spread particularly in infected individuals who remain asymptomatic for years before progressing to overt AIDS.