Matrix remodeling in the lung during HIV infection

描述(申请人提供)：肺是艾滋病毒的重要储存地，也是艾滋病毒复制的场所，可导致病毒引起的肺损伤。艾滋病毒是如何导致直接肺损伤的，以及病毒如何在肺内持续复制，目前尚不清楚。我们发现，HIV感染的淋巴细胞通过分泌TGFbeta1诱导成纤维细胞分泌纤维连接蛋白(FN)，从而促进基质重塑。我们还发现，基质FN和FN的蛋白降解片段III1-C增强了HIV对淋巴细胞的感染，并且FN结合的HIV比未结合的病毒保持感染的时间更长。我们假设，细胞外基质，特别是纤维连接蛋白，增强了肺内的艾滋病毒感染，反过来，肺内的艾滋病毒增加了促进炎症和纤维化的蛋白分解活性。为了验证这一点，我们将：1.确定基质FN如何增加HIV的传染性和稳定性。基质纤维连接蛋白和肺泡巨噬细胞的相互作用可能有助于肺内持续的病毒库。2.确定HIV感染细胞的基质降解特性。我们假设HIV感染改变了净蛋白水解酶的活性，从而导致基质降解和生物活性蛋白水解物片段的产生。3.检测HIV感染和HAART对支气管肺泡灌洗液(BALF)中蛋白酶活性的影响。艾滋病毒诱导的蛋白水解酶活性可能通过产生可增强感染的纤维连接蛋白的蛋白水解性片段、通过裂解天然的艾滋病毒感染抑制物如SDF-1α或通过产生直接导致肺损伤的蛋白水解性片段而促成持续性感染和肺损伤。因此，我们将检测HAART前后HIV患者BALF中的蛋白水解酶活性。4.利用蛋白质组学的新方法，通过确定BALF蛋白随时间的表达模式，建立HIV和HAART在肺中的“蛋白质时间表”。蛋白质组学分析还可能识别艾滋病毒引起的肺部疾病的新的生物标志物，并揭示艾滋病毒引起的肺部疾病的意外途径。这些实验将增加我们对艾滋病毒在肺部感染的非传染性并发症的理解，例如涉及基质重塑的肺气肿，并提供对艾滋病毒诱导的空域环境中蛋白质分解的后果的洞察。

DESCRIPTION (provided by applicant): The lung is an important reservoir of HIV and site of HIV replication, which results in virus-induced lung injury. How HIV leads to direct lung injury, and how virus replication is sustained within the lung, are not known. We found that HIV-infected lymphocytes induced fibroblasts to secrete fibronectin (FN), by elaboration of TGFbeta1, thus contributing to matrix remodeling. We also showed that matrix FN and a proteolytic fragment of FN,III1-C, enhanced HIV infection of lymphocytes and that FN-bound HIV remained infectious longer than unbound virus. We hypothesize that extracellular matrix, specifically fibronectin, enhances HIV infection within the lung and, conversely, that HIV within the lung increases proteolytic activity that contributes to inflammation and fibrosis. To test this we will: 1. Determine how matrix FN increases infectivity and stability of HIV. Interactions of matrix fibronectin and alveolar macrophages may contribute to persistent viral reservoir in the lung. 2. Define the matrix-degrading properties of HIV-infected cells. We hypothesize that HIV infection alters net protease activity, which results in matrix degradation and generation of biological active proteolytic fragments. 3. Determine the effect of HIV infection and HAART on protease activity of bronchoalveolar lavage fluid (BALF). HIV-induced protease activity may contribute to persistent infection and lung injury by generating proteolytic fragments of fibronectin that enhance infection, by cleaving natural inhibitors of HIV infection such as SDF-1alpha or by generating proteolytic fragments that directly cause lung injury. Therefore, we will measure proteolytic activity in BALF samples from HIV patients before and following HAART. 4. Develop a "protein timeline" of HIV and HAART in the lung by identifying patterns of BALF protein expression over time using new methodologies in proteomics. Proteomic analysis may also identify new biomarkers of HIV-induced lung disease and reveal unsuspected pathways in HIV induced lung disease. These experiments will increase our understanding of the non-infectious complications of HIV infection in the lung, such as emphysema that involves matrix remodeling, and provide insight into consequences of HIV-induced proteolysis in the airspace environment.