Bispecific T cell engagers for the treatment of pancreatic ductal adenocarcinoma

- 项目概要/摘要- 胰腺导管腺癌（PDAC）是最致命的癌症之一。存活率低， 这主要是由于PDAC诊断的晚期和缺乏有效的治疗。远景目标 该研究计划的一个重要目的是发现治疗PDAC的新的免疫学方法。 我们小组和其他人的初步研究表明，前梯度-2（AGR 2）蛋白，一种 蛋白质二硫键异构酶（PDI）家族成员，在PDAC肿瘤发生过程中被诱导， >90%的PDAC患者表达。AGR 2具有细胞内氧化折叠功能， 从细胞定位到PDAC细胞的表面并脱落到肿瘤微环境中。我们 假设AGR 2是用于开发PDAC靶向免疫疗法的可行靶标， 将使用一种新的免疫治疗候选药物来验证这一理论。在初步研究中，我们生成了一个 通过噬菌体展示筛选获得了一种具有自主知识产权的抗AGR 2单链抗体片段（scFv），并构建了一种 双特异性T细胞受体（BiTE）结合AGR 2和CD 3，其是T细胞受体复合物的亚基。 我们发现BiTE参与刺激T细胞受体信号传导、T细胞活化/增殖和T细胞凋亡。 诱导细胞模型中AGR 2阳性PDAC细胞的杀伤。本研究的具体目标是：（1） 通过亲和力成熟提高我们的scFv的AGR 2结合亲和力，和（2）为了证明高效力T 优化的BiTE分子在体外和基因工程中对PDAC细胞的细胞依赖性杀伤 PDAC的小鼠模型（GEMM）。这些目标建立在现有文献的明确理论基础上， 强有力的初步数据这项工作是创新的，因为我们将调查的活动和机制， 用于治疗PDAC的新的免疫疗法候选药物，PDAC是一种需要新疗法的癌症。在 此外，我们希望这项研究将揭示新的方法和机制，产生抗肿瘤， PDAC中的免疫应答，现有的免疫疗法迄今为止对其无效。

---Project Summary/Abstract ---- Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest forms of cancer. Poor survival rates are largely due to the late stage at which PDAC is diagnosed and a lack of effective therapies. The long-term goal of this research program is to discover new immunotherapeutic approaches for the treatment of PDAC. Preliminary studies by our group and others have shown that the Anterior Gradient-2 (AGR2) protein, a member of the protein disulfide isomerase (PDI) family, is induced during PDAC oncogenesis and highly expressed in >90% of PDAC patients. AGR2 has intracellular oxidative folding function and is also released from the cell where it localizes to the surface of PDAC cells and is shed into the tumor microenvironment. We hypothesize that AGR2 is an actionable target for the development of PDAC targeted immunotherapies and will test that theory using a new immunotherapy drug candidate. In preliminary studies we generated a proprietary anti-AGR2 single chain antibody fragment (scFv) by phage display screening and constructed a bispecific T-cell engager (BiTE) that binds to AGR2 and CD3, which is a subunit of the T cell receptor complex. We found that BiTE engagement stimulates T cell receptor signaling, T cell activation/proliferation, and T cell induced killing of AGR2-positive PDAC cells in cellular models. The specific objectives of this study are: (1) to improve the AGR2 binding affinity of our scFv via affinity maturation, and (2) to demonstrate high potency T cell dependent killing of PDAC cells by an optimized BiTE molecule in vitro and in genetically engineered mouse models (GEMMs) of PDAC. These aims are built on clear rationale from the existing literature and strong preliminary data. This work is innovative because we will investigate the activity and mechanism of a new immunotherapy drug candidate for the treatment of PDAC, which is a cancer in need of new therapies. In addition we expect that this study will reveal new methods and mechanisms for generating an anti-tumor immune response in PDAC, for which existing immunotherapies have thus far been ineffective.