Engineering High-Affinity T Cell Receptors Against Cancer Antigens

描述（由申请人提供）： T细胞具有强大的能力来调查和破坏已被感染或转化的细胞。T细胞表达T细胞受体（TCR），其特异性地识别与细胞表面上的主要组织相容性复合体（MHC）分子结合的短肽片段。各种研究已经表明，患者肿瘤中T细胞（肿瘤浸润淋巴细胞，TIL）的更大浸润与改善的预后相关。如果肽/MHC被TCR以足够的亲和力识别，则T细胞被激活并释放破坏宿主细胞的颗粒酶和穿孔素。尽管正常的免疫系统有可能调查和破坏转化细胞，但已建立的癌症显然避免了这种免疫介导的识别和破坏。免疫疗法的首要目标是促进癌症pepMHC复合物的TCR识别，以便可以利用身体自身的免疫系统来破坏转化的组织。在肿瘤发生过程中，细胞通过MHC分子表达突变和异常过表达的蛋白质。实现癌组织的T细胞识别的一种机制是工程化高亲和力TCR以结合这些癌症pepMHC复合物。已经鉴定了超过300种与不同类型的癌组织相关的pepMHC复合物，但是很少分离出对这些pepMHC复合物特异的高亲和力TCR。该项目的目标是设计针对几种癌症pepMHC复合物的高亲和力TCR，并测试它们在癌症的过继性T细胞模型中促进肿瘤消退的能力。此外，该项目旨在开发一种更有效的分离高亲和力TCR的方法。 我的具体目标是：目标1：利用定向进化和亲和力成熟技术开发针对生存素/HLA-A2的高亲和力TCR。目前，我们已经分离出针对癌抗原Mart 1和WT 1的高亲和力TCR。开发一种针对生存素的高亲和力受体将增加在其他目的中测试的受体的库。上午2：检测嵌合抗原受体（CAR）形式的高亲和力TCR，其将介导体内T细胞对Mart 1、WT 1和Survivin抗原的活性。这一目标将使人们更好地了解如何在体内使用高亲和力TCR，以便未来的临床开发成为可能。目的3：建立一种利用通用支架快速分离高亲和力TCR的方法。目前用于分离高亲和力TCR的技术是耗时的，包括分离T细胞克隆，然后逐个操作TCR基因。这一目标将开发一个最佳的支架库，以便实现高亲和力TCR的快速分离，促进它们在多种癌症和更多患者的过继性T细胞免疫治疗中的应用。

DESCRIPTION (provided by applicant): T cells have the powerful capability to survey and destroy cells that have become infected or transformed. T cells express T cell receptors (TCRs), which specifically recognize short peptide fragments bound to major histocompatibility complex (MHC) molecules on the cell surface. Various studies have shown that greater infiltration of T cells (tumor infiltrating lymphocytes, TILs) in a patient's tumor correlates with improved prognosis. If a peptide/MHC is recognized with sufficient affinity by the TCR, the T cell is activated and releases granzymes and perforins that destroy the host-cell. Despite potential for the normal immune system to survey and destroy transformed cells, established cancers have clearly avoided such immune-mediated recognition and destruction. An overarching goal of immunotherapy is to promote TCR recognition of cancer pepMHC complexes so that the body's own immune system can be harnessed to destroy transformed tissues. During oncogenesis, cells express mutated and aberrantly overexpressed proteins via MHC molecules. One mechanism to achieve T cell recognition of cancerous tissue is to engineer high-affinity TCRs to bind to these cancer pepMHC complexes. Over 300 pepMHC complexes associated with different types of cancerous tissue have been identified, yet very few high-affinity TCRs specific for these pepMHC complexes have been isolated. The goal of this project is to engineer high-affinity TCRs against several cancer pepMHC complexes and test their ability to promote tumor regression in adoptive T cell models of cancer. Also, this project seeks to develop a more efficient method for isolating high-affinity TCRs. My specific aims are: Aim 1: To develop a high-affinity TCR against survivin/HLA-A2 using directed evolution and affinity maturation. Currently, we have isolated high-affinity TCRs against the cancer antigens Mart1 and WT1. Developing a high-affinity receptor against survivin will add to repertoire to receptors tested in other aims. Am 2: To test high-affinity TCRs in a chimeric antigen receptor (CAR) format that will mediate T cell activity against Mart1, WT1 and Survivin antigens in vivo. This aim will allow a better understanding of how high-affinity TCRs can be used in vivo, so that future clinical development is possible. Aim 3: To develop a method for rapid isolation of high-affinity TCRs using a universal scaffold. Current techniques for isolating high-affinity TCRs are time-consuming, involving isolation of T cell clones followed by one-by-one manipulation of the TCR genes. This aim will develop an optimal scaffold library so that rapid isolation of high-affinity TCRs can be achieved, facilitating their use in adoptive T cell immunotherapies for diverse cancers and many more patients.