Isolation and Characterization of Prostrate Antigen Specific High Affinity TCR

描述(申请人提供)：到目前为止，限制前列腺癌患者免疫治疗效果的一个关键因素是前列腺癌细胞表达的TAA的免疫原性很差。这种低免疫原性可能是由于对正常前列腺细胞表达的抗原的免疫耐受所致。因此，治疗前列腺癌的治疗性疫苗和过继T细胞转移方法的开发多年来进展甚微。本申请中概述的研究利用了一种基因治疗方法，该方法能够将正常外周血T细胞的特异性重新定向到识别肿瘤细胞。我们将利用这样一个事实，即我们的T细胞靶向的前列腺癌细胞表达的抗原肽在前列腺癌患者中不需要是免疫原性的，因为我们将为他们提供他们自己的T细胞，这些T细胞经过改造可以识别他们的肿瘤。鉴于女性没有前列腺癌，她们的T细胞不应该对前列腺癌抗原产生耐受性。此外，他们的T细胞可能比男性类似的T细胞表达更高的T细胞受体对前列腺癌抗原的亲和力。因此，这项应用建议从女性的PBL中分离前列腺癌反应性T细胞克隆。然后，我们将从这些前列腺癌反应性T细胞中鉴定和克隆T细胞受体，并构建能够工程正常PBL来源的T细胞识别前列腺癌细胞的逆转录病毒载体。然后，我们将评估这些TCR转导的T细胞在体外和体内的有效性。虽然这项应用将现有的技术和已建立的免疫学概念应用于前列腺癌患者的新治疗方法的开发，但我们认为T细胞的非正统来源为这项研究增添了新的转折。除了为前列腺癌患者提供新的治疗选择的可能性外，这项研究还将增加我们对前列腺癌抗原耐受性的理解，这可能有助于那些开发新的前列腺癌疫苗的人。公共卫生意义：这项建议旨在分离携带与前列腺特异性膜抗原(PSMA)和前列腺干细胞抗原(PSCA)反应的高亲和力T细胞受体(TCR)的T细胞克隆，并将其工程于正常外周血T细胞以识别前列腺癌细胞，以鉴定其有效性。我们的建议的力量在于它的创新假设，即从正常成年女性分离的前列腺抗原反应性T细胞比从男性分离的类似T细胞具有更高的亲和力和更高的亲和力TCRs。在这个项目成功完成后，我们希望通过为局部和晚期前列腺癌患者提供他们自己的T细胞，通过高亲和力TCR来识别和杀死他们的肿瘤，从而规避免疫耐受。

DESCRIPTION (provided by applicant): A key factor that has so far limited the efficacy of immunotherapy for prostate cancer patients is the poor immunogenicity of TAA expressed by prostate cancer cells. This poor immunogenicity is likely due to immunologic tolerance to antigens expressed by normal cells of the prostate. As a result, the development of therapeutic vaccines and adoptive T cell transfer approaches for treating prostate cancer has made little progress over the years. The studies outlined in this application take advantage of a gene therapy approach that is capable of redirecting the specificity of normal peripheral blood T cells to recognize tumor cells. We will take advantage of the fact that the antigenic peptides expressed by prostate cancer cells that are targeted by our T cells need not be immunogenic in prostate cancer patients since we would be providing them their own T cells engineered to recognize their tumors. Given that women lack prostate glands, their T cells should not be tolerant to prostate cancer antigens. Furthermore, their T cells may express T cell receptors with higher affinity for prostate cancer antigens than similar T cells in men. Therefore, this application proposes to isolate prostate cancer reactive T cell clones from the PBL of women. We will then identify and clone the T cell receptors from these prostate cancer reactive T cells and construct retroviral vectors capable of engineering normal PBL-derived T cells to recognize prostate cancer cells. We will then evaluate these TCR transduced T cells for their efficacy in vitro and in vivo. While this application applies existing technologies and established immunologic concepts to the development of new treatments for prostate cancer patients, we believe the unorthodox source of T cells adds a novel twist to this study. In addition to the potential for a new treatment option for prostate cancer patients, this study will increase our understanding of tolerance to prostate cancer antigens that may assist those in developing new prostate cancer vaccines. PUBLIC HEALTH RELEVANCE: This proposal is to isolate T cell clones bearing high affinity T cells receptors (TCR) reactive with prostate specific membrane antigen (PSMA) and prostate stem cell antigen (PSCA) and to characterize their efficacy after engineering them on normal peripheral blood T cells to recognize prostate cancer cells. The strength of our proposal is its innovative hypothesis that prostate antigen reactive T cells isolated from normal adult females would have higher avidity and express higher affinity TCRs than similar T cells isolated from males. On successful completion of this project we hope to circumvent immunologic tolerance in patients with local and advanced prostate cancer by providing them with their own T cells engineered with high affinity TCR to recognize and kill their tumors.