HIV-1 INFECTION IN FETAL BRAIN CELL CULTURES AND PEDIATRIC AIDS BRAIN TISSUE

胎儿脑细胞培养物和儿科艾滋病脑组织中的 HIV-1 感染

• 批准号: 3782435
• 负责人: E O MAJOR
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3782435
• 关键词: HIV envelope protein gp41; HIV infections; antiviral agents; astrocytes; embryo /fetus tissue /cell culture; enzyme inhibitors; gene induction /repression; glial fibrillary acidic protein; human immunodeficiency virus 1; human tissue; interleukin 1; microorganism culture; nucleic acid probes; pediatric AIDS; phorbols; protein kinase C; provirus; transcription factor; transfection; tumor necrosis factor alpha; virus DNA; virus RNA; virus genetics; virus protein; virus replication

Possible causes of HIV-1- induced neurotoxicity include infection of select populations of glial cells. We have established a useful model of HIV-1 infection in human fetal brain cell cultures to study the mechanisms by which this may occur. Through either infection with virions or transfection with proviral DNA, human fetal astrocytes quickly develop a non-cytopathic but productive infection which gradually diminishes to a persistent infection without viral expression at the RNA or protein levels. However, HIV-1 expression can be reactivated by the cytokines TNF-alpha and IL-1 beta as well as by phorbol myristic acid (PMA), a potent activator of protein kinase C. PKC inhibitors such as H-7, an isoquinolone, can block reactivation by TNF-alpha and PMA, an effect which in the case of PMA is likely due to a reduction in the transcriptional activator NF kappa-B. Intracellular pathways involved in HIV~1 reactivation appear to be cell-type dependent as other factors known to induce HIV-1 from human monocyte cells such as GM-CSF, IL-6, IL-2 and interferon do not activate HIV-1 from astrocytes. Extraction of mRNA following stimulation with TNF-alpha or IL-1 beta demonstrates the presence of mRNA for nef, tat and rev proteins, of which nef is the most abundant and longest lasting. We have evidence that infection of glial cells is important in vivo in that tissue from 4 of 12 pediatric AIDS brains has revealed glial fibrillary acidic protein (GFAP) positive astrocytes with positive hybridization to HIV-1 radiolabeled probes. In several of these sections, there was no evidence for the HIV-1 antigens p24 and gp41. These results suggest that astrocytes may harbor an undetectable HIV-1 proviral DNA that can be activated in the brain through cytokines. TNF-alpha and IL-1 beta are reported to be present in AIDS brain tissue in high concentrations. Other work has shown that these cytokines are produced by astrocytes in response to HIV infection. Further study of the molecular and biochemical aspects of HIV~1 infection of astrocytes and its clinical correlates in pediatric AIDS encephalopathy are currently in progress.

HIV-1诱导的神经毒性的可能原因包括 选择神经胶质细胞群。 我们建立了一个有用的模型， HIV-1感染人胎脑细胞的机制研究 这可能会发生。 通过感染病毒体， 用前病毒DNA转染，人胎儿星形胶质细胞迅速发育， 非细胞病变但产生性感染，逐渐减少至 持续感染，RNA或蛋白质上无病毒表达 程度. 然而，HIV-1的表达可以被细胞因子重新激活， TNF-α和IL-1 β以及佛波醇肉豆蔻酸（PMA）， 蛋白激酶C的有效激活剂。 PKC抑制剂如H-7， 异喹诺酮类药物能够阻断TNF-α和PMA的再激活，这种作用 在PMA的情况下，可能是由于转录水平的降低， 活化剂NF κ B。 HIV~1的细胞内通路 再活化似乎是细胞类型依赖性的，因为其他已知的因素， 从人单核细胞如GM-CSF、IL-6、IL-2和 干扰素不激活来自星形胶质细胞HIV-1。 mRNA的提取 用TNF-α或IL-1 β刺激后， 存在nef、达特和rev蛋白的mRNA，其中nef是最多的 丰富而持久。 我们有证据表明神经胶质细胞感染 在12例儿童艾滋病患者中， 大脑显示胶质细胞酸性蛋白（GFAP）阳性 星形胶质细胞与HIV-1放射性标记探针杂交呈阳性。 在 在这些切片中，没有证据表明HIV-1抗原 p24和gp 41。 这些结果表明，星形胶质细胞可能含有一种 无法检测到的HIV-1前病毒DNA，可以在大脑中被激活， 细胞因子 据报道，TNF-α和IL-1 β存在于艾滋病中， 高浓度的脑组织 其他研究表明， 细胞因子由星形胶质细胞响应HIV感染而产生。 HIV~1感染的分子生物学研究进展 星形胶质细胞在儿童艾滋病脑病中的表达及其临床相关性 目前正在进行中。