Novel synthetic receptors with improved antigen specificity and specificity for cancer therapy

摘要 利用基因转移修饰的T细胞表达T细胞受体或合成嵌合体的过继细胞治疗 特异性T细胞识别肿瘤相关抗原的抗原受体(CAR)在 患有难治性恶性肿瘤的患者。临床数据表明，低水平表达的肿瘤细胞 抗原或具有异质性抗原表达的可逃逸并导致复发。解决障碍 由于肿瘤细胞上的抗原密度较低，我们基于以下原理设计了新型的合成杂化受体 T细胞受体信号具有优越的特性，并可能能够消除低水平的肿瘤细胞 抗原水平。为了解决肿瘤细胞上异种抗原表达的障碍，我们设计了 依赖于共局定位的正交蛋白质开关，在 细胞表面。原则上，这种方法可以指示T细胞消除异质性肿瘤细胞群 并保留正常的抗原阳性细胞，扩大了可以安全靶向的抗原星座。 这项应用的研究将推动这两类下一代合成受体的发展 多个临床相关的靶抗原，实现更有效、更安全地清除低度恶性肿瘤 和/或异质性抗原表达。具体目标是： 目的1：研究新型CAR/TCR杂合受体在原代T细胞中的信号和功能。 表达CAR-TCR的T细胞的信号、突触形成、抗原敏感性以及体内功能和命运 通过慢病毒转导或敲入T细胞受体α基因位点引入的杂交受体将 与表达CD28/CD3z和4-1BB/CD3z细胞靶向相同抗原的T细胞进行比较。 目的：评价CAR/TCRs基因工程T细胞的嵌合共刺激受体。我们会 通过共表达嵌合体评价CAR/TCR工程T细胞中是否加入共刺激分子 与肿瘤相关配体结合的分子将增强抗肿瘤功能。 目的设计针对多发性骨髓瘤(MM)抗原的OR和AND门控CARS并进行评价 它们阻止肿瘤逃逸的能力。多发性骨髓瘤对单一靶向T细胞治疗的反应 抗原，但肿瘤细胞的异质性允许逃逸。共定位依赖的蛋白质开关可以 将开发和评估对异质肿瘤细胞进行OR和AND逻辑门控识别 靶向多发性骨髓瘤抗原。

Abstract Adoptive cell therapy using T cells modified by gene transfer to express T cell receptors or synthetic chimeric antigen receptors (CARs) that specify T cell recognition of tumor associated antigens can be effective in patients with refractory malignancies. Clinical data has shown that tumor cells that express low levels of antigen or that have heterogeneous antigen expression can escape and cause relapse. To address the barrier of low antigen density on tumor cells, we have designed novel synthetic hybrid receptors based on principles of T cell receptor signaling that have superior properties and may be capable of eliminating tumor cells with low antigen levels. To address the barrier of heterogeneous antigen expression on tumor cells, we designed colocalization-dependent orthogonal protein switches that perform ‘AND’, ‘OR’, and ‘NOT’ Boolean logic at the cell surface. In principle, this approach can instruct T cells to eliminate heterogeneous tumor cell populations and spare normal antigen positive cells, extending the constellation of antigens that can be safely targeted. The studies in this application will advance these two classes of next generation synthetic receptors for multiple clinically relevant target antigens to achieve more effective and safe elimination of tumors with low and/or heterogeneous antigen expression. The specific aims are: Aim 1: To evaluate signaling and function of novel CAR/TCR hybrid receptors in primary T cells. Signaling, synapse formation, antigen sensitivity, and in vivo function and fate of T cells expressing CAR-TCR hybrid receptors introduced by lentiviral transduction or by knock-in to the T cell receptor alpha gene locus, will be compared to T cells expressing CD28/CD3z and 4-1BB/CD3z CARs targeting the same antigens. Aim 2: To evaluate chimeric costimulatory receptors for T cells engineered with CAR/TCRs. We will evaluate whether the addition of costimulation in CAR/TCR engineered T cells by co-expressing chimeric molecules that engage a tumor associated ligand will enhance antitumor function. Aim 3 To design OR and AND gated CARS specific for multiple myeloma (MM) antigens and evaluate their ability to prevent tumor escape. Multiple myeloma is responsive to T cell therapy targeting single antigens, but tumor cell heterogeneity allows escape. Co-localization dependent protein switches that can perform OR and AND logic gated recognition of heterogeneous tumor cells will be developed and evaluated for targeting multiple myeloma antigens.