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

描述（由申请方提供）：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定位。这个过程是由在感染部位充当化学引诱物的趋化因子的作用协调的。我们最近证明，白细胞也可以通过称为趋化性或化学排斥的趋化因子受体介导的机制被排斥于包括趋化因子和病毒蛋白（包括SDF-1和HIV-1包膜蛋白，gp 120）的特定试剂（Nature Medicine.2000.6.543; J Virol. 2004：2004：78.5184;在J.Mol. Med.中综述。2005.83：752）。我们提出，T细胞，特别是CTL的化学排斥反应，在响应CXCR 4或CCR 5结合gp 120产生的逆转录病毒感染的细胞中发挥作用的一种新的机制，其中HIV-1逃避免疫系统。首先，我们开发了新型全定量测定法来测量白细胞向SDF-1或HIV-1gp 120的迁移，并证明化学排斥是通过与化学吸引不同的信号通路介导的（Nature Med.，J. Virol op cit; J.勒克. Biol.2005. in press.）。为了确定T细胞对SDF-1或HIV-1gp 120的化学排斥是否在体内可证实，我们建立了用于定量白细胞化学排斥的新测定，并随后证实了其在生理和病理过程中的作用，包括胸腺移出和癌症的免疫逃避（J.Clin.Invest.2004）。2002.109：1101; J.Immunol.2005.175：5115）（J.Immunol.AcceptedDec.2005）。我们还表明，抗原特异性CTL和单核细胞在体外和体内远离结合HIV-1 gp 120的X4或R5，并且这种反应严重依赖于包膜蛋白的V3环的存在（. Virol.同上。我们已经证明，在试点工程细胞表达gp 120排斥，从而失调的CTL迁移和功能在体外和随后的定位在体内，并在急性SHIV-1感染的猴子的淋巴结内检测到的gp 120的化学排斥浓度。我们现在计划探索这些发现与HIV/AIDS的机制和病理生理学相关性。本研究的目的是：1. HIV-1gp 120诱导CTL化学排斥的机制和逆转录病毒蛋白的化学排斥浓度对CTL功能的影响。2.使用多光子活体显微镜和MRI对染料或纳米磁性标记的CTL进行体内成像，定量X4 gp 120对小鼠模型中CTL迁移、定位和功能的影响。3.组织中gp 120梯度的定量和建模以及与急性SHIV-1感染猴中CTL的定位和功能的相关性HIV-1 gp 120诱导的CTL化学排斥对HIV/AIDS的病理生理学相关性的这种集中和创新的探索得到了逆转录病毒学家，免疫学家和生物工程师之间的协同和持续合作的支持，并获得了最近开发的用于检查T细胞迁移和体外和体内定位的完全定量技术。我们希望，通过这种方式，描绘出一种新的机制，通过这种机制，HIV-1逃避免疫系统和HIV-1感染者的新的免疫靶点。

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.