INTERACTIONS OF HUMAN RETROVIRUSES WITH HEMATOPOIETIC AND ADHERENT CELLS

本节的总体目标是更好地理解 宿主细胞和其他辅助因子对人类逆转录病毒复制的影响。 在 特别是单核细胞/巨噬细胞，HIV-1感染的储库， 艾滋病患者，被证明能够限制HIV-1的表达。 在 THP-1，单核细胞样细胞系，两类限制性HIV-1 观察到表达：1）低水平和2）无表达（潜伏的）。 潜伏感染细胞在5-氮胞苷后产生感染性病毒 exposure. 相反，LPS和几种细胞因子可以增加病毒感染， 在有限的细胞中产生，但不能激活潜伏感染 细胞 因此，HIV表达的限制和潜伏状态 可能通过不同的机制发生在单核细胞中。 在有限的艾滋病毒- 1表达THP-1，DNA结合蛋白复合物的缺乏， HIV-1增强子被认为是伴随着生产显着减少 病毒RNA 这种结合的缺失定位于NF-κ B HIV增强子的65+50 kD NF-κ B异二聚体区域， 优先丢失。 将纯化的NF-κ B蛋白添加到核中 来自表达受限的细胞的提取物恢复了这种结合。 此外，用脱氧胆酸钠处理这些核提取物 恢复异二聚体结合，表明NF-κ B的特异性抑制剂， ~B存在于这些细胞中。 因此，65+50 kD的结合 HIV-I增强子的异二聚体可以在 单核细胞 对潜伏感染的THP-1的研究表明，这些细胞 用ConA-1共培养可诱导表达感染性病毒， 活化的T细胞，分离自正常的HIV阴性供体。 新鲜 来自无症状血清阳性个体的分离的粘附单核细胞 经检查发现含有潜伏的艾滋病毒。 共培养后， 单核细胞与来自HIV阴性正常供体的Con A活化的T细胞， 这些潜伏的单核细胞培养物表达病毒。 艾滋病毒产生于 活化的潜伏单核细胞感染T细胞，并可导致病毒诱导的 病理 这些结果表明，受感染的单核细胞 在病毒持续存在和传播中产生很少或不产生病毒 特别是在多年无症状的感染者中 才发展成艾滋病

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.