Targeting GRP94-TGF-beta Pathway for Cancer Immunotherapy

项目总结 作为内质网中普遍存在的HSP90类似物，GRP94在蛋白质质量中起着重要作用 通过参与未折叠蛋白反应和内质网相关的内质网调节分泌途径 蛋白质降解途径。我的实验室已经证明，GRP94是一个具有战略意义的目标 癌症，因为它控制着细胞生长、迁移、免疫耐受和 分化，包括整合素、TLRs、IGF-II、Wnt共同受体LRP6和GARP(或LRRC32)。加普 (主要是糖蛋白A重复)负责表面对接和激活潜伏的TGFb和 这项建议的一个重点我们通过免疫学和 生化研究包括：1)GARP是调节肿瘤免疫逃避的重要分子 多种细胞类型(如癌细胞、血小板、调节性T细胞、B细胞)。2)我们发现了一种新的机制 细胞表面GARP-TGFb复合体通过GARP蛋白水解酶的裂解而激活TGFb。3)GARP一直是 发现在多种人类癌症中异常表达，通过两种固有的癌细胞- 和-外在机制。4)临床前研究表明GARP是一种新的癌症治疗靶点 免疫疗法。这些成就加深了我们对GRP94及其客户的研究 网络将有助于更好地了解癌症中的这种伴侣生物学，并开发新的癌症 治疗药物，单独或与经批准的免疫治疗药物联合使用。在下一阶段的研究中， 我们将解决这样的假设，即GRP94/GARP靶向治疗应用于多种易患癌症将 克服对检查点抑制剂的免疫抵抗力。 首先，我们将确定GRP94调控TGFb生物发生的作用和分子机制。 激活和发送信号。这一目标将集中在GRP94-GARP复合体的结构分析和解决 GRP94折叠另外两个调节TGFb信号的分子：LRRC33和LRRC33的机制 LRG1。其次，我们将开发针对GRP94和GARP的新型癌症免疫治疗策略。这个 目标是通过里程碑驱动，在几个临床前线索中提升顶级一流代理人(S) 策略。这包括抑制GARP裂解的药物、GARP特异性抗体、类药物GRP94选择性 抑制物、针对细胞表面GRP94(EctoGRP94)的抗体优先表达于癌细胞，以及 表达抗人嵌合抗原受体(CAR)单链抗体的T细胞 EctoGRP94与T细胞信号转导基序(GRP94-CAR-T)融合。总体而言，这项研究的影响在于 GRP94在调控TGFb途径中的基本认识及其在下一步开发中的前景 新一代免疫治疗剂。

PROJECT SUMMARY As a ubiquitous HSP90 paralog in the endoplasmic reticulum (ER), GRP94 plays important roles in protein quality control in the secretory pathway by participating in both the unfolded protein response and the ER-associated protein degradation pathway. My laboratory has demonstrated that GRP94 is a strategically important target for cancer, because it controls multiple key molecular pathways in cell growth, migration, immune tolerance and differentiation, including integrins, TLRs, IGF-II, Wnt co-receptor LRP6, and GARP (or LRRC32). GARP (Glycoprotein A Repetitions Predominant) is responsible for surface docking and activation of latent TGFb and a focus of this proposal We have made significant contributions to this area through immunological and biochemical studies, including: 1) that GARP is an important molecule for cancer immune evasion via regulating multiple cell types (e.g., cancer cells, platelets, regulatory T cells, B cells). 2) We discovered a novel mechanism of TGFb activation from cell surface GARP-TGFb complex via proteolytic cleavage of GARP. 3) GARP has been found to be aberrantly expressed in multiple human cancers to promote oncogenesis via both cancer cell-intrinsic and -extrinsic mechanisms. 4) Preclinical studies suggest that GARP is a novel therapeutic target for cancer immunotherapy. These accomplishments have deepened our conviction that the study of GRP94 and its client network will lead to better understanding of this chaperone biology in cancer and to development of novel cancer therapeutics, alone or in combination with approved immunotherapeutic agents. In the next phase of the study, we will address the hypothesis that GRP94/GARP-targeted therapy applied to multiple vulnerable cancers will overcome immune resistance to checkpoint inhibitors. First, we will determine the roles and molecular mechanism involved in GRP94 regulation of TGFb biogenesis, activation and signaling. This aim will focus on structural analysis of the GRP94-GARP complex, and on resolving mechanisms of GRP94 in folding two other molecules important in regulating TGFb signaling: LRRC33 and LRG1. Second, we will develop novel cancer immunotherapeutic strategies targeting GRP94 and GARP. The goal is to advance the top first-in-class agent(s) among several pre-clinical leads through a milestone-driven strategy. This includes agents to inhibit GARP cleavage, GARP-specific antibodies, drug-like GRP94-selective inhibitors, antibodies against the cell surface GRP94 (ectoGRP94) preferentially expressed on cancer cells, and T cells engineered to express chimeric antigen receptor (CAR) composed of a single-chain antibody against ectoGRP94 fused with T cell signaling motifs (GRP94-CAR-T). Overall, the impact of this study lies in fundamental understanding of GRP94 in regulating the TGFb pathway and in developing promising next generation immunotherapeutic agents.