REGULATION OF HIV-1 CORECEPTORS

趋化因子是一类结构上相关的多肽， 通过白细胞表面G蛋白偶联受体相互作用 调节多种生物和生化活动，如粘连， 定向迁移和激活。他们扮演着重要的角色 许多炎症性疾病的病理生理学。趋化因子受体CCR5或 CXCR4被确定为人类进入人体必需的辅助受体 免疫缺陷病毒HIV-1进入CD4阳性细胞。而CCR5是目标 对于初级病毒的进入，CXCR4可能在进展到 由无症状感染引起的艾滋病。父提案的总体目标 是描绘CXCR4信号通路，脱敏和 利用标记表位稳定共表达的RBL-2H3细胞内化 天然的或突变的CXCR4以及人类的CD4。 在这个艾滋病FIRCA中，索扎尼博士建议使用许多试剂 (表位标记的绿色荧光蛋白标记的天然和突变的CXCR4 DNA 和转导的RBL细胞系)为亲本制定的建议确定 丝裂原活化蛋白激酶在配体SDF-1激活cPLA2中的作用及其相关性 通过药理学和生物化学手段实现白细胞趋化的途径 接近。HIV-1包膜糖蛋白(Gp120)诱导 将研究表达CXCR4的RBL-2H3中第二信使的形成。 MAPK和cPLA2的激活将被评估并与 Gp120蛋白诱导细胞迁移的能力。上级实验室是 利用HIV-1感染允许的人脑星形胶质瘤细胞系U87， 转染人CD4和天然或突变CXCR4的作用 HIV-1感染中的信号平衡和内化。关于中国农业发展的研究 RBL中的cPLA2和MAPKs为将其推广到人类提供了基础 母实验室中的细胞系，并确定这些通路的作用 在HIV-1感染中。

The chemokines are a family of structurally related peptides that interact through cell surface G-protein coupled receptors in leukocytes to mediate diverse biological and biochemical activities such as adhesion, directed migration and activation. They play a major role in the pathophysiology of many inflammatory disorders. Chemokine receptors CCR5 or CXCR4 were identified as essential co-receptors for the entry of human immunodeficiency virus HIV-1 into CD4 positive cells. While CCR5 is the target for the entry of primary viruses CXCR4 may be important in the progression to AIDS from asymptomatic infection. The overall objective of the parent proposal is to delineate the pathways of CXCR4 signaling, desensitization and internalization using the RBL-2H3 cells stably co-expressing epitope-tagged native or mutated CXCR4 along with human CD4. In this AIDS-FIRCA, Dr. Sozzani proposes to utilize many reagents (epitope-tagged, green fluorescent protein tagged native and mutated CXCR4 DNAs and transfected RBL cell lines) developed for the parent proposal to determine the role of MAPKs on cPLA2 activation by the ligand SDF-1 and the relevance of this pathway to leukocyte chemotaxis using both pharmacological and biochemical approach. The ability of the HIV-1 envelope glycoproteins (gp120) to induce second messenger formation in CXCR4-expressing RBL-2H3 will be investigated. Activation of MAPKs, and cPLA2 will be evaluated and correlated with the ability of gp120 proteins to induce cell migration. The parent laboratory is utilizing and HIV-1 infection permissive human astroglioma cell line, U87, transfected with human CD4 and native or mutated CXCR4 to determine the role of the signaling evens and internalization in HiV-1 infection. The studies on cPLA2 and MAPKs in RBLs will provide a basis for extension of the same to human cell lines in the parent laboratory and to determine the role of these pathways in HIV-1 infection.