BIOLOGY OF KSHV/HHV8 G PROTEIN COUPLED RECEPTOR

描述(申请人提供)：本研究旨在探讨KSHV ORF74编码的病毒G蛋白偶联受体(VGPCR)在KS致病和KSHV生物学中的作用。VGPCR在KSHV的病理生物学中是一个关键基因，因为它可以在体外和体内触发重要的信号级联反应和诱导概括KS表型的细胞反应。这些包括激活血管内皮生长因子介导的血管生成和肿瘤的发生。本申请所产生的工具和知识，以及KSHV领域的最新进展，为开展vGPCR病理生物学的明确研究和评估其作为治疗靶点的有效性提供了必要的工具和知识。我们的工作假设是，裂解复制过程中vGPCR的表达具有调节和宿主病毒基因表达的能力，从而在刺激和旁分泌血管生成过程中增加内皮细胞的存活率。这些旨在促进病毒复制和感染的活性在EC中是癌前和促血管生成的，因此在EC中vGPCR的表达可以促进KS细胞和血管的生长，并导致肿瘤转化。为了研究vGPCR在KSHV感染和致病中的功能作用，我们将通过趋化因子Gro-a的激活和vGPCR零突变来调节KSHV感染过程中vGPCRa的表达。为了研究KSHV在感染和复制中的作用，我们将在细胞和分子水平上确定vGPCR调节如何影响KSHV在293和内皮细胞中感染和复制的能力。2-研究在KSHV感染过程中vGPCR表达对细胞存活、存活信号和KSHV基因转录的影响。为了确定vGPCR在KSHV介导的Kaposi肉瘤发病机制中的作用，我们将利用体外和体内模型研究1-vGPCR对KSHV感染的血管生成旁分泌激活的贡献。2-vGPCR在KSHV感染内皮细胞KS样表型重现中的作用。3-vGPCR参与原代内皮细胞永生化、转化和血管生成激活。除了测试vGPCR作为艾滋病-KS治疗靶点的有效性外，这项研究还将提供在KSHV感染背景下识别vGPCR致病反应的模型，并确定能够阻断KSHV致病的针对vGPCR功能的方法。

DESCRIPTION (provided by applicant): This proposal is directed to investigate the role in KS pathogenesis and KSHV biology of the viral G protein coupled receptor encoded by ORF74 of KSHV (vGPCR). vGPCR appear to be a critical gene in KSHV pathobiology because it can trigger important signaling cascades and induce cellular responses that recapitulate the KS-phenotype in vitro and in vivo. These include activation of VEGF mediated angiogenicity and tumorigenesis. The tools and knowledge generated by the present application in addition to recent advances in the KSHV field provide the necessary armamentarium to undertake a definitive study in vGPCR pathobiology and assess its validity as therapeutic target. Our working hypothesis is that vGPCR expression during lytic replication has the capacity to regulate and host viral gene expression leading to increased endothelial cell survival during and paracrine angiogenic stimulation. That these activities that are directed to enhance viral replication and infection are pre-neoplastic and pro-angiogenic in EC, and thus vGPCR expression in EC can promote KS-cell and vessel growth and also lead to oncogenic transformation. To study the functional role of vGPCR in KSHV infection and pathogenesis we will modulate vGPCR expression during KSHV infection by activation with the chemokine Gro-a and by vGPCR-null mutations. To study the role of KSHV in infection and replication we will 1-Determine at the cellular and molecular level how vGPCR-modulation affects the ability of KSHV to infect and replicate in 293 and endothelial cells. 2- Study how vGPCR expression affects cell survival, survival signaling and KSHV gene transcription during KSHV infection. To determine the role of vGPCR in KSHV mediated Kaposi's sarcoma pathogenesis we will study 1- The contribution of vGPCR to paracrine activation of angiogenesis by KSHV infection using "in vitro" and "in vivo" models. 2- The contribution of vGPCR to the recapitulation of KS-like phenotypes in KSHV infected endothelial cells. 3- The participation of vGPCR in primary endothelial cell immortalization, transformation and angiogenic activation. In addition to test the validity of vGPCR as target for AIDS-KS therapy, this research will provide models that identify vGPCR pathogenic responses in the context of KSHV infection and identify approaches targeted to vGPCR function that are able to block KSHV pathogenesis.