Interactions Between HIV Gag and Exosomal Proteins

HIV Gag 和外泌体蛋白之间的相互作用

• 批准号: 7016241
• 负责人: Francisco Gonzalez-Scarano
• 金额: $ 10.34万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7016241
• 关键词: AIDS dementia complex; HIV infections; animal tissue; annexins; binding sites; gag protein; gene mutation; human tissue; macrophage; microglia; protein localization; protein protein interaction; protein structure function; virus infection mechanism

HIV associated Dementia (HAD) is an important co-morbidity of HIV infection. Its less severe form appears to be resistant to highly active anti-retroviral therapy (HAART) and HIV infected macrophages (MDM) and microglia are key to its development. Because of their importance in this and other facets of HIV infection, the cycle in MDM has been studied extensively, and most investigators believe that macrophage infection can be long-lived and produce little cytopathology, making these cells ideal potential reservoirs for the virus in a treated individual, and that while most steps in the infectious process parallel those in lymphocytes, virus assembly and egress are different, and involve intracytoplasmic assembly and routing into multivesicular bodies (MVBs) in preference to budding at the plasma membrane. Subsequent release of virus is believed to take place via an exocytotic pathway involving direct fusion of plasma and MVB limiting membranes. Using a model microglia/macrophage infection that has been modified so that there is low production of virus, we have identified binding between gag and an annexin II (Anx2), a pleiotropic protein involved in exosomal formation and fusion. This protein is expressed to high levels in macrophages and microglia, particularly in the infected brain. In this proposal we will develop these preliminary results in three specific aims. In the first aim, we will further determine the effects of reduction of Anx2 in MDM on HIV infection, and analyze the differences between the protein expressed in activated vs. non-activated MDM. In the second specific aim, we will map the binding sites between p55/p24 and Anx2 and introduce mutations into HIV proviruses, to determine the effects on viral infection. In the third specific aim we will study its surface expression and study Anx2 distribution in the HIV and SIV infected brain, and perform collocation experiments using fluorescence tagged molecules. These results will expand our understanding of lentiviral infection of macrophages, and potentially provide an additional target for therapeutic intervention in HIV and HAD.

HIV相关性痴呆（HAD）是HIV感染的重要共病。其不太严重的形式似乎对高效抗逆转录病毒疗法 (HAART) 具有抵抗力，而 HIV 感染的巨噬细胞 (MDM) 和小胶质细胞是其发展的关键。由于巨噬细胞在 HIV 感染的这一方面和其他方面的重要性，MDM 中的循环已被广泛研究，大多数研究人员认为巨噬细胞感染可以长期存在并且产生很少的细胞病理学，使这些细胞成为病毒在体内的理想潜在储存库。接受治疗的个体，虽然感染过程中的大多数步骤与淋巴细胞中的步骤相似，但病毒 组装和出口是不同的，并且涉及胞质内组装和进入多泡体（MVB），而不是在质膜上出芽。据信病毒的后续释放是通过涉及血浆和 MVB 限制膜直接融合的胞吐途径发生的。使用经过改造的小胶质细胞/巨噬细胞感染模型，病毒产量较低，我们鉴定了 gag 与膜联蛋白 II (Anx2) 之间的结合，膜联蛋白 II (Anx2) 是一种参与外泌体形成和融合的多效性蛋白。这种蛋白质在巨噬细胞和小胶质细胞中高水平表达，特别是在受感染的大脑中。在本提案中，我们将针对三个具体目标制定这些初步结果。在第一个 目的，我们将进一步确定MDM中Anx2减少对HIV感染的影响，并分析激活与非激活MDM中表达的蛋白之间的差异。在第二个具体目标中，我们将绘制p55/p24和Anx2之间的结合位点，并将突变引入HIV原病毒中，以确定对病毒感染的影响。在第三个具体目标中，我们将研究其表面表达并研究Anx2在HIV和SIV感染大脑中的分布，并使用荧光标记分子进行搭配实验。这些结果将扩大我们对巨噬细胞慢病毒感染的理解，并可能为 HIV 和 HAD 的治疗干预提供额外的靶点。