Cytoplasmic HIV-RNA in monocytes determines microglial activation and neuronal cell death in HIV-associated neurodegeneration
Cytoplasmic HIV-RNA in monocytes determines microglial activation and neuronal cell death in HIV-associated neurodegeneration
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DOI：
10.1016/j.expneurol.2014.08.011
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发表时间：
2014-11-01
影响因子：
5.3
通讯作者：
Chan, Andrew
中科院分区：
文献类型：
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作者：
Faissner, Simon;Ambrosius, Bjoern;Chan, Andrew
尽管抗逆转录病毒治疗非常有效，但艾滋病毒相关神经认知障碍（HAND）仍然非常普遍。受hiv感染的独立于病毒复制的单核细胞激活的小胶质细胞的直接神经毒性可能解释了这一观察结果。为了研究潜在的分子和病毒决定因素，将转染hiv颗粒的人单核细胞（U937）与原代人小胶质细胞或星形胶质细胞共培养。利用基因工程的hiv颗粒检测了感染的关键步骤。用流式细胞术检测共培养上清中促炎/神经毒性细胞因子的水平。用大鼠皮层原代神经元分析上清液介导的神经毒性。为了证实我们的发现，神经心理无症状HIV阳性（HIV+）患者（n = 45）脑脊液（CSF）中的细胞因子谱与神经丝H （NfH）相关，作为神经元/轴突变性的替代指标。与HIV直接暴露于小胶质细胞相比，只有HIV转导的单核细胞才能强烈激活人小胶质细胞，CXCL10、CCL5的分泌增强证明了这一点。CCL2和IL-6（1.3 ~ 7.1倍，p < 0.01）导致神经毒性增加2倍（p < 0.001）。在直接比较中，由hiv转导的单核细胞激活星形胶质细胞是有限的。使用不同的突变hiv -颗粒，我们表明细胞质HIV-RNA在单核细胞中的存在是这种独特的小胶质细胞激活模式和随后的神经元细胞死亡的病毒决定因素；病毒基因的逆转录和表达不是必需的。在症状前HIV+患者的脑脊液中，CXCL10、CCL5和IL-6与NfH相关，作为神经退行性变和CSF多细胞症的替代标志物。总之，单核细胞中的胞质病毒RNA对于随后的小胶质细胞激活和神经毒性是必需的：激活的星形胶质细胞可能会增加神经炎症。此外，即使在临床前HIV患者中也会发生神经炎症和神经退行性变，并且与体外调节的细胞因子有关。我们的数据可能有助于开发生物标志物和胶质细胞导向的HAND治疗方法。(C) 2014爱思唯尔公司版权所有。
Despite highly active antiretroviral therapy, HIV-associated neurocognitive disorders (HAND) are still highly prevalent. Direct neurotoxicity of microglia activated by HIV-infected monocytes independent from viral replication may account for this observation. To investigate underlying molecular and viral determinants, human monocytoid cells (U937) transduced with HIV-particles were co-cultured with primary human microglia or astrocytes. Using genetically-engineered HIV-particles key steps of infection were examined. Levels of pro-inflammatory/neurotoxic cytokines were investigated in co-culture supernatants by flow cytometry. Neurotoxicity mediated by the supernatants was analysed using primary cortical rat neurons. To corroborate our findings, cytokine profiles in cerebrospinal fluid (CSF) of neuropsychologically asymptomatic HIV positive (HIV+) patients (n = 45) were correlated with neurofilament H (NfH) as surrogate of neuronal/axonal degeneration. In contrast to direct exposure of HIV to microglia, only the presence of HIV-transduced monocytoid cells strongly activated human microglia as evidenced by enhanced secretion of CXCL10, CCL5. CCL2, and IL-6 (1.3-7.1-fold: p < 0.01) leading to two-fold increased neurotoxicity (p < 0.001). In direct comparison, astrocyte activation by HIV-transduced monocytoid cells was limited. Using different mutant HIV-particles we show that the presence of cytoplasmic HIV-RNA in monocytoid cells is the viral determinant for this unique microglial activation pattern and subsequent neuronal cell death; reverse transcription and expression of viral genes were not essential. In CSF of presymptomatic HIV+ patients, CXCL10, CCL5 and IL-6 were correlated with NfH as surrogate marker of neurodegeneration as well as CSF-pleocytosis. In conclusion, cytosolic viral RNA in monocytes is mandatory for subsequent microglial activation and neurotoxicity: activated astrocytes may augment neuroinflammation. In addition, neuroinflammation and neurodegeneration occur even in preclinical HIV patients and are associated with cytokines regulated in vitro. Our data may aid in the development of biomarkers and glia-directed therapeutic approaches of HAND. (C) 2014 Elsevier Inc. All rights reserved.