FUNCTIONAL STUDIES OF HIV-TAT EFFECTS ON ENDOTHELIUM

描述(改编自申请人的描述) HIV-1Tat蛋白由受感染的T细胞分泌， 单核巨噬细胞，先前的研究表明它可以有效地改变 内皮细胞的生长、迁移和黏附相互作用。功能界别 TAT对内皮细胞的影响似乎是通过与其特异性结合而发生的。 血管内皮生长因子受体Flk-1/KDR及其受体 α5β1、αvβ3和αβ5表面整合素。这 研究小组最近发现，TAT可以激活Flt4受体 血管内皮生长因子-C/VRP以及几个Src激酶家族成员，该蛋白 酪氨酸磷酸酶SHPTP-2、粘着斑激酶FAK和RAFTK/Pyk2 以及p44/42 MAP激酶ERK1和ERK2。此外，TAT对人 脐静脉内皮细胞(HUVEC)或骨髓内皮细胞 (BMEC)导致一氧化氮(NO)释放，蛋白质增加 内皮型一氧化氮合酶(ENOS)水平及血管生成 β趋化因子单核细胞趋化蛋白(MCP-1)。不是一个重要的 血管内皮生长因子对血管细胞生长、趋化和调控的影响 渗透性。MCP-1促进单核巨噬细胞的募集 T细胞，并被认为是介导T细胞跨 内皮细胞单层。对TAT的观察，再加上之前 已报道的研究表明，它可以破坏几种重要的内皮细胞 表面血管内皮生长因子和整合素受体触发信号的协同作用 转导通路。 这项提议试图系统地描述信号通路 由TAT在HUVEC和BMEC中使用，并将其与由 血管内皮生长因子-A和血管内皮生长因子C/血管紧张素Ⅱ受体的表达，以确定TAT介导的血管紧张素转换酶机制 有丝分裂、趋化、黏附分子表达及NO和MCP-1 放手。从这些研究中获得的信息应该有助于 明确HIV-1如何导致内皮功能障碍和损伤，并协助 在创造新的疗法来保护艾滋病毒感染的宿主方面。

DESCRIPTION (Adapted from the applicant's description) The HIV-1 TAT protein is secreted from infected T-cells and monocyte-macrophages, and prior studies suggest it can potently alter endothelial growth, migration and adhesive interactions. The functional effects of TAT on endothelium appear to occur via its specific binding to the Flk-1/KDR receptor for vascular endothelial growth factor (VEGF) and to the alpha5 beta1, alphav beta3 and alphav beta5 surface integrins. This group recently have found that TAT can activate the FLT4 receptor for VEGF-C/VRP, as well as several Src kinase family members, the protein tyrosing phosphatase SHPTP-2, the focal adhesion kinases FAK and RAFTK/Pyk2 and the p44/42 MAP kinases Erk1 and 2. Moreover, TAT treatment of human umbilical vein endothelium cells (HUVEC) or bone marrow endothelium cells (BMEC) resulted in the release of nitric oxide (NO), increased protein levels of endothelial nitric oxide synthase (eNOS), and generation of the beta-chemokine monocyte chemotactic protein (MCP-1). NO is an important mediator of VEGF effects on vascular cell growth, chemotaxis and permeability. MCP-1 contributes to recruitment of monocyte-macrophages and T-cells and is believed to mediate transmigration of T-cells across an endothelial monolayer. The observations on TAT, coupled with previously reported work, suggest that it can subvert several vital endothelial functions by co-opting surface VEGF and integrin receptor triggered signal transduction pathways. This proposal seeks to systematically characterize the signaling pathways utilized by TAT in HUVEC and BMEC, and contrast them with those triggered by VEGF-A and VEGF-C/VRP, in order to determine the mechanisms of TAT-mediated mitogenesis, chemotaxis, adhesion molecule expression, and NO and MCP-1 release. The information obtained from these studies should help in defining how HIV-1 may cause endothelial dysfunction and injury, and assist in the creation of novel therapeutics to protect the HIV infected host.