T Cell Receptor - Based Assays for Cancer Diagnosis

描述（由申请人提供）：在过去的十年中，许多作为T细胞抗原的肿瘤相关肽（在MHC蛋白的背景下）已经被确定。基于这些发现，以及最近对T细胞生物学其他方面的见解，人们将继续努力开发基于T细胞的癌症治疗方法。正如现在单克隆抗体疗法所显示的那样，这些T细胞策略的成功将需要诊断分析，以确定患者的癌症是否抗原阳性（即在其表面表达肿瘤pep/MHC）。在这项提案中，两位在T细胞受体（TCR）工程（David Kranz）和T细胞导向癌症治疗（Phil Greenberg）方面具有互补专业知识的研究人员将合作开发基于TCR的癌症诊断检测方法。我们最近表明，有可能设计出针对pepMHC分子的高亲和力tcr。这些tcr的可溶性形式可以作为新的探针，在MHC I类分子的背景下，鉴定和定量呈现在肿瘤细胞表面的肿瘤抗原肽的数量。针对其中一种肿瘤抗原的tcr，即来自致癌Wilm肿瘤蛋白的肽WT1，将在本研究中进行探索。这个

DESCRIPTION (provided by applicant): In the past decade, many tumor-associated peptides that serve as T cell antigens (in the context of MHC proteins) have been identified. Based on these findings, and recent insights into other aspects of T cell biology, there continues to be considerable effort on the development of T cell-based therapies of cancer. As is now apparent with monoclonal-antibody therapies, success with these T cell strategies will require diagnostic assays that determine whether a patient's cancer is antigen-positive (i.e. expresses the tumor pep/MHC on its surface). In this proposal, two investigators who have complementary expertise in T cell receptor (TCR) engineering (David Kranz) and in T cell-directed therapies of cancer (Phil Greenberg) will collaborate on the development of TCR-based assays for cancer diagnosis. We have recently shown that it is possible to engineer high-affinity TCRs that are specific for pepMHC molecules. Soluble forms of these TCRs can serve as novel probes to identify and quantitate the amount of a tumor antigen peptide presented on the surface of a tumor cell, in the context of an MHC class I molecule. TCRs against one of these tumor antigens, peptide WT1 from the oncogenic Wilm's tumor protein, will be explored in the present study. The goals of this proposal are to: Aim 1. Develop sensitive T cell receptor-based assays for detection of specific peptide-MHC on tumor cells, using an already available high-affinity TCR (m67a) specific for the pep/MHC complex SIYR/Kb. Aim 2. Engineer high-affinity TCRs against mouse WT1/Dh complexes, an animal model that will be critical for the development of optimal therapeutics and diagnostics against WT1 in humans. Aim 3. Engineer high-affinity TCRs against human WT1/HLA-A2 complexes, the antigenic complex known be expressed endogenously by various A2+ human tumors, including many leukemias. These TCR reagents should not only be useful for distinguishing tumor cells from normal cells, based on detecting the expression of a tumor antigen, but they should also identify patients with tumors that might be most susceptible to immunotherapeutic intervention.