Elucidating the molecular and cellular mechanisms of immune evasion in pancreatic cancer

项目摘要/摘要 胰腺癌(PDAC)预后很差，仍然是一个严重的未得到满足的公共卫生需求。最近认识到胰腺癌的一个子集含有潜在的新抗原，这使得人们对确定PDAC免疫逃避的分子和细胞机制以指导有效的治疗策略产生了浓厚的兴趣，从而利用适应性免疫系统来治疗这种疾病。然而，精确定义肿瘤反应性T细胞隔间的困难阻碍了先前描述PDAC逃避免疫根除的全谱机制的努力。我推测，PDAC的一个子集通过肿瘤反应性T细胞的功能障碍和/或定位改变而逃脱免疫监视。我们的初步研究，使用新抗原表达的PDAC临床前模型来评估肿瘤特异性免疫反应，发现很大一部分肿瘤获得了逃避免疫清除的能力，并且新抗原特异性COS·肿瘤浸润性淋巴细胞(TILs)采用多种功能障碍状态。此外，我们最近证明CD155/TIGIT轴既促进并维持PDAC的免疫逃避(Freed-Pastor等人)。癌症细胞，在印刷中)。在这项建议中，我利用最近开发的临床前模型、单细胞图谱的进展以及高度多元化的成像方式来询问小鼠和人类PDAC中的细胞毒T细胞室。具体地说，我将使用单细胞转录和高度多元化的免疫荧光技术来评估TIGIT/PD-1共同阻断加CD40激动剂对PDAC肿瘤免疫微环境的影响。我还将利用流式细胞术和多重成像来研究临床前模型中肿瘤进展过程中T细胞表型和定位的时空动态，并比较T细胞对不同新抗原的反应。此外，我将对直接从胰腺癌患者身上分离的TIL进行高分辨率分析。总而言之，这些研究为加速PDAC的有效免疫治疗带来了巨大的希望。这项拟议的研究将在麻省理工学院科赫综合癌症研究所进行，由癌症生物学和肿瘤免疫学的国际领先者泰勒·贾克斯博士指导，达纳-法伯癌症研究所的领先胰腺癌研究员布莱恩·沃尔平博士共同指导。重要的是，这项研究战略是全面培训计划的一部分，以支持我过渡到基础和转化性癌症生物学和肿瘤免疫学的独立研究生涯。我的科学顾问(Arlene Sharpe博士、Stefani Spranger博士和Osama Rahma博士)都是杰出的专家，具有与拟议研究高度相关的经验。我的长期目标是领导一个独立的学术研究小组，专注于破译PDAC逃避免疫清除的分子和细胞机制，以便这些见解可以用于指导抗击胰腺癌和其他癌症的治疗策略。K08奖项将为继续指导研究提供关键的保护时间，并使其能够成功过渡到独立研究。

PROJECT SUMMARY/ABSTRACT Pancreatic adenocarcinoma (PDAC) carries a dismal prognosis and remains a critical unmet public health need. The recent recognition that a subset of pancreas cancer harbors potential neoantigens has intensified interest in defining the molecular and cellular mechanisms of immune evasion in PDAC to guide effective therapeutic strategies that leverage the adaptive immune system in this disease. However, difficulty in precisely defining the tumor-reactive T cell compartment has hampered prior efforts to delineate the full spectrum of mechanisms by which PDAC evades immune eradication. I hypothesize that a subset of PDAC escapes immune surveillance through dysfunction and/or altered localization of tumor-reactive T cells. Our preliminary studies, using neoantigen-expressing preclinical models of PDAC to evaluate tumor-specific immune responses, have revealed that a significant subset of tumors acquire the ability to evade immune clearance and that neoantigen-specific cos• tumor-infiltrating lymphocytes (TILs) adopt multiple states of dysfunction. Additionally, we recently demonstrated that the CD155/TIGIT axis both promotes and maintains immune evasion in PDAC (Freed-Pastor et al. Cancer Cell, in press). In this proposal, I leverage recently developed preclinical models, advances in single-cell profiling, and highly multiplexed imaging modalities to interrogate the cytotoxic T cell compartment in murine and human PDAC. Specifically, I will evaluate the effects of TIGIT/PD-1 co-blockade plus CD40 agonism on the tumor-immune microenvironment in PDAC using single-cell transcriptomic and highly multiplexed immunofluorescence technologies. I will also utilize flow cytometry and multiplexed imaging to investigate the spatiotemporal dynamics of T cell phenotypes and localization during tumor progression in preclinical models, and compare T cell responses to different neoantigens. Furthermore, I will perform high-resolution profiling on TILs isolated directly from pancreas cancer patients. Collectively, these studies hold tremendous promise for accelerating effective immune-based therapies for PDAC. The proposed research will be performed at the Koch Institute for Integrative Cancer Research at MIT, under the guidance of Dr. Tyler Jacks, an international leader in cancer biology and tumor immunology, with co-mentorship by Dr. Brian Wolpin, a leading pancreas cancer researcher at the Dana-Farber Cancer Institute. Importantly, this research strategy is one part of a comprehensive training program to support my transition to an independent research career in basic and translational cancer biology and tumor immunology. My scientific advisors (Drs. Arlene Sharpe, Stefani Spranger, and Osama Rahma) are distinguished experts with experience highly relevant to the proposed research. My long-term goal is to lead an independent academic research group, focused on deciphering the molecular and cellular mechanisms by which PDAC evades immune clearance, such that these insights can be used to guide therapeutic strategies to combat pancreas cancer and other cancers. The K08 award will provide pivotal protected time for continued mentored research and enable a successful transition to independence.