Pathways of Neuronal Damage Involving Macrophage-Glia Interactions In Vivo

我们认为，hiv -1相关痴呆（HAD）中的星形胶质细胞功能障碍是通过其与受感染的脑单核吞噬细胞（MP；血管周围和实质巨噬细胞和小胶质细胞）的相互作用发生的。我们将利用我们中心新开发的蛋白质组学和成像设备来研究这是如何发生的。磁共振成像（1HMRI）， 1HMRS光谱和单质子发射计算机断层扫描将访问人类HAD和HIV脑炎（HIVE）啮齿动物模型的细胞运动和功能。这项工作将研究MP感染和/或激活如何影响星形胶质细胞的神经调节功能，以及探索星形胶质细胞新生的原发性感染。提出MP促炎因子（如肿瘤坏死因子、喹啉酸和血小板活化因子）的分泌减弱星形胶质细胞信号通路，导致脑源性神经营养因子、神经源性神经营养因子、神经生长因子和/或转化生长因子β等胶质营养因子下调，并减弱谷氨酸转运蛋白功能。hiv感染的巨噬细胞分泌物（细胞或病毒产物）也可能包括星形胶质细胞产生神经毒素（例如，一氧化氮），谷氨酸，白细胞介素-1 β， mp -星形胶质细胞相互作用将被研究其影响自分泌和/或旁分泌胶质神经毒素扩增和趋化功能的能力。病毒和星形胶质细胞分泌反应的相对作用将被研究其在星形胶质细胞中的影响

We propose that astrocyte dysfunction in HIV-1-associated dementia (HAD) occurs through its Interactions with infected brain mononuclear phagocytes (MP; perivascular and parenchymal macrophages and microglia). We will study how this occurs taking advantage of a newly developed proteomics and imaging facllity within our center. Magnetic resonance imaging (1HMRI), 1HMRS spectroscopy and single proton emission computed tomography will access cell movement and functlon in a rodent animal model of human HAD and HIV encephalitis (HIVE). The work will investigate how MP Infection and/or activation affects astrocyte neuroregulatory functions as well as explore primary infection of astrocytes de novo. It is proposed that secretion of MP pro-inflammatory factors (for example, tumor necrosis factor, quinolinlc acid and platelet activating factor) attenuates astrocyte signaling pathways leading to the down regulation of glial trophins including brain derived neurotrophic factor, glial derived neurotrophic factor, nerve growth factor, and/or transforming growth factor beta as well as attenuating glutamate transporter function, HIV-infected macrophages secretions (cellular or viral products) may also inclte the production of neurotoxins from astrocytes (for example, nitric oxide), glutamate, interleukin-1beta, MP-astrocyte interactions will be investigated for their abilities to affect autocrine and/or paracrine amplification of glial neurotoxins and chemotactic function. The relative role of virus and astrocyte secretory responses will be studied for its influence in the neuropathogenesis of HIV infection in a severe combined immunodeficient (SCID) mouse model of human disease. SCID mice will be injected intracerebrally with productively infected human astrocytes with vesicular stomatitis virus expressing HIV-1, with lymphotropic (LAI) or macrophage tropic (DVJ, ADA or JR-FL) viruses. The generation of cytotoxlc T lymphocytes from reconstituted HIVE mice will be used to eliminate infected macrophages from the brain and permit the assessment and evaluation of astrocyte repair processes. Lastly, a novel, state-of-art proteomics facility that includes on-line protein sequencing, will establish a comprehensive database of global changes of protein expression in human primary astrocytes as it relates to cell functlon. Altogether, these works will permit the determination of astrocyte and neuronal functions evaluated as a consequence of HIV-1 infection, MP function and chemotaxis in laboratory and animal models of human HAD. Most importantly, the project has strong collaborative ties with each of the other projects focusing on a unique but as yet understudied part of NeuroAIDS, namely the role played by astrocytes in the disease process.