Development of a novel platform for the discovery of antigen-specific TCRs

开发用于发现抗原特异性 TCR 的新平台

• 批准号: 10203877
• 负责人: Christopher Seet
• 金额: $ 19.69万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10203877
• 关键词: Address; Adoptive Cell Transfers; Adoptive Immunotherapy; Affinity; Antigen Presentation; Antigens; Autoantigens; Autologous; Baltimore; Binding; Biological; Biological Assay; Blood; CD8-Positive T-Lymphocytes; CTAG1 gene; Clinical; Clone Cells; Cloning; Collaborations; Detection; Development; Disease; Economics; Engineering; Epitopes; Face; Frequencies; Gays; Generations; Goals; HLA-A gene; Haplotypes; Hematologic Neoplasms; Hematology; Hematopoietic stem cells; Human; Immunotherapy; In Vitro; K-Series Research Career Programs; Lead; Logistics; MART-1 Tumor Antigen; Malignant neoplasm of prostate; Mentors; Mentorship; Methods; Modeling; Molecular; Mutation; Nature; Normal tissue morphology; Oncology; Organoids; Outcome; Outcome Study; Patients; Physicians; Privatization; Production; Property; Prostate; Prostate Cancer therapy; Publishing; Reproducibility; Research; Research Proposals; Sampling; Scientist; Series; Source; Specific qualifier value; Specificity; System; T cell differentiation; T cell regulation; T-Cell Receptor; T-Lymphocyte; T-cell receptor repertoire; Technology; Therapeutic; Thymus Gland; Training Support; Transgenes; Tumor Antigens; Umbilical Cord Blood; Validation; Work; antigen-specific T cells; base; cancer immunotherapy; cancer therapy; career; cell mediated immune response; clinical development; clinically translatable; cross reactivity; engineered stem cells; hematopoietic stem cell differentiation; in vivo Model; instructor; interest; malignant breast neoplasm; neoantigens; new technology; novel; novel strategies; patient population; patient subsets; peripheral blood; peripheral tolerance; pre-clinical; prediction algorithm; reconstitution; success; tumor

PROJECT SUMMARY As a Clinical Instructor in Hematology/Oncology, my career goal is to become an independent physician scientist with a scientific focus on developing new approaches to cancer immunotherapy. This K award period will provide the critical training and support to achieve this goal. This research proposal extends from published work I developed under the mentorship of Dr. Gay Crooks over the past two years. Our interest in the molecular regulation of T cell differentiation from hematopoietic stem and progenitor cells (HSPCs) led us to the discovery that an “artificial thymic organoid” (ATO) culture system permits in vitro thymic-like differentiation of human HSPCs to fully mature human T cells in a robust and highly reproducible manner. This finding was significant in that prior strategies to direct in vitro T cell differentiation from human HSPCs were largely unable to support the generation of functional T cells. We found that ATOs supported the differentiation of cord blood (CB) HSPCs to CD8+ T cells with a highly diverse T cell receptor (TCR) repertoire comparable to that of naïve T cells from the thymus or blood; and further demonstrated that HSPCs engineered with a TCR specific for a tumor-associated antigen efficiently generated mature, tumor-specific T cells in ATOs (Seet et al., Nature Methods, 2017). The focus of this proposal is to exploit a unique property of the ATO system for the de novo discovery of high affinity antigen specific TCRs for cancer immunotherapy. TCR-directed adoptive cell immunotherapy currently relies on the labor-intensive identification from patient samples of TCRs specific to “public” tumor- associated antigens. However, as many public tumor antigens are non-mutated self-antigens, T cells expressing high affinity TCRs against these targets are typically deleted in the thymus during negative selection, ultimately resulting in the isolation of low affinity TCRs from patient samples. We hypothesize that T cells generated in vitro in ATOs are not subject to negative selection, and thus may present a unique source of high affinity tumor antigen specific TCRs for immunotherapy. In this proposal, I will develop a novel ATO-based platform for the discovery of antigen specific TCRs against public tumor antigens; characterize the nature of ATO-derived TCRs relative to those isolated from peripheral blood; and finally apply these methods to the proof-of-concept capture and preclinical validation of TCRs reactive to prostate cancer specific antigens, a disease in which the identification of tumor-specific TCRs from patients has thus far proved challenging. This is an ambitious project, but one in which the chances of success are maximized through collaboration with the labs of my mentor Dr. Gay Crooks, co-mentor Dr. Owen Witte at UCLA, and Dr. David Baltimore at Caltech. Development of a new technology for rapidly identifying high-affinity TCRs against public tumor antigens would be a significant contribution to the field of immunotherapy research, lead to clinically translatable outcomes, and open promising avenues of further independent research.

项目摘要 作为一名血液学/肿瘤学临床讲师，我的职业目标是成为一名独立的医生 他是一位科学家，专注于开发癌症免疫疗法的新方法。本次K奖期间 将为实现这一目标提供关键的培训和支持。 这个研究计划是从我在Gay Crooks博士的指导下发表的工作中延伸出来的 在过去的两年里。我们对造血干细胞T细胞分化的分子调控的兴趣， 干细胞和祖细胞（HSPCs）的研究使我们发现，“人工胸腺类器官”（ATO）培养物 系统允许人HSPC在体外胸腺样分化为完全成熟的人T细胞， 和高度可重复的方式。这一发现是重要的，因为先前的策略是指导体外T细胞 从人HSPC分化的细胞在很大程度上不能支持功能性T细胞的产生。我们 发现ATO支持脐带血（CB）HSPC分化为具有高度多样性的CD 8 + T细胞， T细胞受体（TCR）库与来自胸腺或血液的幼稚T细胞的库相当;并且进一步 证明了用对肿瘤相关抗原特异性的TCR工程化的HSPC有效地产生了 ATO中的成熟肿瘤特异性T细胞（Seet等，Nature Methods，2017）。 该提案的重点是利用ATO系统的独特性质来重新发现 用于癌症免疫治疗的高亲和力抗原特异性TCR。TCR介导的过继细胞免疫治疗 目前依赖于从患者样本中对“公共”肿瘤特异性TCR的劳动密集型鉴定- 相关抗原。然而，由于许多公共肿瘤抗原是非突变的自身抗原， 表达针对这些靶标的高亲和力TCR的胸腺在阴性对照期间通常缺失。 选择，最终导致从患者样品中分离低亲和力TCR。我们假设T 在ATO中体外产生的细胞不经历负选择，因此可能是一种独特的细胞来源。 用于免疫治疗的高亲和力肿瘤抗原特异性TCR。在这个建议中，我将开发一种新颖的基于ATO的 用于发现针对公共肿瘤抗原的抗原特异性TCR的平台; ATO衍生的TCR相对于从外周血分离的TCR的比较;最后将这些方法应用于 对前列腺癌特异性抗原有反应的TCR的概念验证捕获和临床前验证， 因此，在某些疾病中，从患者中鉴定肿瘤特异性TCR迄今已被证明具有挑战性。 这是一个雄心勃勃的项目，但其中成功的机会是通过合作最大化 我的导师Gay Crooks博士，UCLA的共同导师Owen Witte博士和巴尔的摩的大卫博士的实验室 加州理工一种快速鉴定抗肿瘤高亲和力TCR新技术的建立 抗原将是免疫治疗研究领域的重大贡献，导致临床 可翻译的结果，并为进一步的独立研究开辟了有前途的途径。