Role of chemokine receptors in HIV infection and progression.

1. CCR3在HIV感染中的作用。C CR3是趋化因子（如eotaxin）的受体，最近被确定为某些类型HIV-1的辅助受体。尽管CCR3在人外周血嗜酸性粒细胞上强烈表达，但在其他细胞类型上的表达及其在HIV感染中的作用尚未完全阐明。在目前的项目中，我们已经建立了抗人CCR3的单克隆抗体。利用表达ccr3的人胶质瘤细胞和嗜ccr3的HIV分离物，我们发现该单抗在体外特异性阻断HIV感染。因此，该单抗为研究HIV共受体CCR3.2的表达和功能提供了有价值的探针。涉及hiv依赖性细胞融合的信号转导通路。利用HIV依赖的细胞融合系统，我们证明细胞查星素D和herbyycin（而不是百日咳毒素）显著抑制HIV进入细胞。此外，共聚焦显微镜显示，在细胞膜即将融合的区域，磷酸酪氨酸蛋白和F- act蛋白更多地共定位。这些结果表明蛋白酪氨酸kin酶级联和细胞骨架重组在依赖hiv的细胞融合中起关键作用。然而，我们发现，即使在缺乏各种非受体酪氨酸激酶（包括Src、Fyn、Lyn、FAK或Abl）的情况下，依赖hiv的细胞融合也可能发生，这表明这些酪氨酸激酶并非hiv进入的绝对必要条件。然而，这些激酶之间通常存在冗余。例如，我们发现fax缺陷细胞表达另一种FAK家族激酶CAKbeta，该激酶被认为可以替代FAK的功能。我们还发现，用SDF1 （HTV辅助受体CXCR4的天然配体）刺激人类T细胞，可诱导p105CasL的酪氨酸磷酸化。由于p105CasL是参与T细胞受体信号级联反应的信号分子，因此由辅受体结合触发的信号可能在HIV感染个体的T细胞功能异常中发挥作用。少

1. The role of CCR3 in HIV infection. C CR3, a receptor for chemokines such as eotaxin, has been recently identified as a coreceptor for certain types of HIV-1. Although CCR3 is strongly expressed on eosinophils in human peripheral blood cells, the expression on other cell types and its role in HIV infection have not been fully elucidated. In the current project, we have established monoclonal antibody against human CCR3. Using CCR3-expressing human glioma cells and CCR3-tropic HIV isolates, we found that this mAb specifically blocked HIV infection in vitro. Thus, this mAb provides a valuable probe in investigating the expression and function of HIV coreceptor, CCR3.2. Signal transduction pathways involving HIVenv-dependent cell fusion. Using HIVenv-dependent cell fusion system, we demonstrated that cytochalacin D and herbimycin but not pertussis toxin significantly inhibited HIV entry to cells. Moreover, confocal microscopy revealed colocalization of phosphotyrosyl proteins and F- act … More in in areas where cell membranes are about to fuse. These results suggest that protein tyrosine kin ase cascades and cytoskeletal reorganization play a critical role in HIVenv-dependent cell fusion. However, we found that HIVenv-dependent cell fusion could occur even in the absence of various non-receptor tyrosine kinases, including Src, Fyn, Lyn, FAK, or Abl, suggesting that these tyrosine kinases are not absolutely necessary for HIV-entry. However, redundancy commonly exists among these kinases. For example, we found that FAX-deficient cells expressed another FAK-family kinase, CAKbeta, which was considered to substitute the function of FAK.We also found that stimulation of human T cells with SDF1, a natural ligand for HTV coreceptor CXCR4, induced tyrosine phosphorylation of p105CasL.Since p105CasL is a signaling molecule involving in T cell receptor signal cascades, signals triggered by coreceptor engagement may play a role in abnormal function of T cells in HIV infected individuals. Less