HIV-1 gp120 induced CTL chemorepulsion:dysregulation of migration & localization

描述(申请人提供)：HIV-1的免疫控制依赖于HIV-1特异性CTL向感染细胞的迁移和与感染细胞的共存。这一过程是通过趋化因子在感染部位作为趋化物质的作用来协调的。我们最近证明，白细胞也可以被包括趋化因子和病毒蛋白(包括SDF-1和HIV-1包膜蛋白gp120)在内的特定药物所排斥，这种排斥机制被称为趋化因子受体或化学排斥(Natural Medicine.2000.6.543；J Virol)。2004年：2004年：78.5184；在《美国医学会杂志.2005.83：78.5184》中审阅)。我们认为，T细胞，特别是CTL对逆转录病毒感染细胞产生的CXCR4或CCR5结合gp120的化学排斥在HIV-1逃避免疫系统的新机制中发挥了作用。首先，我们开发了新的全定量分析方法来测量白细胞向SDF-1或HIV-1gp120的迁移，并证明了化学排斥是通过一种不同于化学吸引的信号途径来介导的(自然医学，J.Virol op cit；J.Leuk)。比奥尔。2005年。在媒体上。)。为了确定T细胞对SDF-1或HIV-1gp120的化学排斥是否在体内表现出来，我们建立了新的定量白细胞化学排斥的方法，并随后证明了它在包括胸腺迁移和癌症免疫逃避在内的生理和病理过程中的作用(J.Clin)。投资。2002.109：1101；J.免疫。2005.175：5115)(J.免疫。2005年12月接受)。我们还表明，在体外和体内，抗原特异性CTL和单核细胞远离与HIV-1 gp120结合的X4或R5，这种反应严重依赖于包膜蛋白(./Virol)的V3环的存在。同上，同上。我们已经在Pilot中证明，在体外，表达gp120的工程细胞排斥并因此失调CTL迁移和功能，以及它们随后在体内的定位，并且在急性Shiv-1感染的猴子的淋巴中可以检测到gp120的化学排斥浓度。我们现在计划探索这些发现与艾滋病毒/艾滋病的机制和病理生理学相关性。这项建议的目的是：1：确定HIV-1gp120诱导CTL化学排斥的机制要素，以及逆转录病毒蛋白的化学排斥浓度对CTL功能的影响。2.用多光子活体显微镜和核磁共振成像技术定量研究X4gp120对CTL在小鼠体内的迁移、定位和功能的影响。3.急性SHV-1感染猕猴组织中gp120梯度的定量和建模及其与CTL定位和功能的相关性逆转录病毒学家、免疫学家和生物工程师之间的协同和持续合作，以及最近开发的用于检测T细胞在体外和体内的迁移和定位的全定量技术，支持了对HIV-1 gp120诱导的CTL化学排斥与HIV/AIDS的病理生理学相关性的重点和创新探索。我们希望通过这种方式，既勾勒出HIV-1逃避免疫系统的新机制，又为HIV-1感染者提供新的免疫治疗靶点。

DESCRIPTION (provided by applicant): Immune control of HIV-1 is dependent on the migration of HIV-1 specific CTLs towards and colocalization with infected cells. This process is orchestrated by the action of chemokines serving as chemoattractants at sites of infection. We recently demonstrated that leukocytes could also be repelled from specific agents including chemokines and viral proteins including SDF-1 and the HIV-1 envelope protein, gp120 via a chemokine receptor mediated mechanism termed fugetaxis or chemorepulsion (Nature Medicine.2000.6.543; J Virol. 2004: 2004: 78.5184; Reviewed in J.Mol.Med..2005.83:752). We propose that T cell and in particular CTL chemorepulsion in response to CXCR4 or CCR5 binding gp120 generated from retrovirally infected cells plays a role in a novel mechanism by which HIV-1 evades the immune system. First we developed novel fully quantitative assays for measuring leukocyte migration to SDF-1 or HIV-1gp120 and demonstrated that chemorepulsion was mediated via a signaling pathway which was distinct from that for chemoattraction (Nature Med., J. Virol op cit; J. Leuk. Biol. 2005. in press.). In order to determine whether T cell chemorepulsion to SDF-1 or HIV-1gp120 was demonstrable in vivo, we established novel assays for quantitating leukocyte chemorepulsion and subsequently demonstrated its role in physiological and pathological processes including thymic emigration and immune evasion by cancer (J. Clin. Invest. 2002.109:1101; J. Immunol. 2005.175:5115)( J. Immunol. Accepted Dec.2005). We also showed that antigen specific CTLs and monocytes move away from X4 or R5 binding HIV-1 gp120 in vitro and in vivo and that this response was critically dependent on the presence of the V3 loop of the envelope protein (./ Virol. op cit.}. We have demonstrated in pilot that cells engineered to express gp120 repel and thereby dysregulate CTL migration and function in vitro and their subsequent localization in vivo and that chemorepellent concentrations of gp120 are detectable within the lymph nodes of acutely SHIV-1 infected monkeys. We now plan to explore the mechanism and pathophysiological relevance of these findings to HIV/AIDS. The aims of this proposal are 1: Definition of mechanistic elements of HIV-1gp120 induced CTL chemorepulsion and the effect of chemorepellent concentrations of the retroviral protein on CTL function. 2. Quantitation of the effects of X4gp120 on CTL migration, localization and function in murine models using multiphoton intravital microscopy and MRI for imaging dye or nanomagnetically labeled CTLs in vivo. 3. Quantitation and modeling of gp120 gradients in tissues and correlation with the localization and function of CTLs in acutely SHIV-1 infected monkeys. This focused and innovative exploration of the pathophysiological relevance of HIV-1 gp120 induced CTL chemorepulsion to HIV/AIDS is supported by synergistic and ongoing collaborations between retrovirologists, immunologists and bioengineers and access to recently developed fully quantitative technologies for examining T cell migration and localization in vitro and in vivo. We hope, in this way, to delineate both a novel mechanism by which HIV-1 evades the immune system and a new immunotherapeutic target for HIV-1 infected individuals.