Improving CAR-T efficacy against solid tumors by expanding lymph node reservoirs of “stem-like” CAR-T cells

通过扩大“干细胞样”CAR-T 细胞的淋巴结储存库来提高 CAR-T 对抗实体瘤的疗效

基本信息

批准号：
10734686
负责人：
Shivani Srivastava
金额：
$ 57.91万
依托单位：
FRED HUTCHINSON CANCER CENTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2028-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10734686
关键词：
Activities of Daily Living Acute Affinity Antigen-Presenting Cells Antigens CAR T cell therapy Cancer Patient Carcinoma Cells Chronic Chronic Lymphocytic Leukemia Clinic Data Defect Effector Cell Engineering Environment Epigenetic Process FRAP1 gene Flow Cytometry Functional disorder Head Hematologic Neoplasms Human Hypoxia Immunotherapy Impairment Infiltration Infusion procedures Maintenance Malignant neoplasm of lung Mediating Memory Microscopy Modeling Mus Ovalbumin PD-1 blockade PD-L1 blockade Patient-Focused Outcomes Patients Peptide/MHC Complex Peptides Phenotype Proliferating ROR1 gene Signal Transduction Sirolimus Solid Neoplasm T-Cell Activation T-Lymphocyte TP53 gene Testing Therapeutic Translating Tumor Antigens Tumor Expansion Tumor Promotion Vaccination Work chimeric antigen receptor T cells clinically relevant comparison control design draining lymph node effector T cell exhaust exhaustion human model improved leukemia lymph nodes mTOR Inhibitor mTOR inhibition malignant breast neoplasm mesothelin mortality neoplastic cell novel novel vaccines overexpression phase I trial preservation programmed cell death protein 1 response self-renewal stem success synergism transcriptome sequencing tumor tumor microenvironment vaccine platform

项目摘要

PROJECT SUMMARY/ABSTRACT Immunotherapy using CAR-T cells has induced dramatic responses in hematological malignancies, but extending this success to more common epithelial cancers, which cause the greatest mortality, has proved more challenging. In a phase 1 trial we conducted, CAR-T cells targeting the tumor-associated antigen ROR1 induced responses in patients with chronic lymphocytic leukemia but became terminally exhausted in breast and lung cancer patients, indicating that strategies to preserve CAR-T function are needed to achieve efficacy in solid tumors. Recent work has demonstrated that a subset of PD-1+Tcf1+ “precursor” exhausted cells (Tpex) is critical for mediating successful tumor responses to immunotherapy. Tpex retain a stem-like capacity for self-renewal, proliferation, and the ability to differentiate into effector-like cells. Interestingly, Tpex preferentially co-localize with antigen-presenting cells (APCs) and reside in tumor-draining lymph nodes (tdLN), where they may be protected from factors in tumors that drive terminal exhaustion, such as more chronic antigen stimulation, mTOR activation, and hypoxia. Unlike conventional T cells, CAR-T cells are activated by intact antigen expressed on tumor cells, not by peptide/MHC complexes expressed on both tumor cells and APCs. This design restricts CAR- T activation exclusively to tumors, where preservation of stem-like qualities may be impaired relative to tdLNs. To test this, we developed a Kras/p53 (KP) autochthonous model of ROR1+ lung cancer that recapitulates the dysfunction of ROR1 CAR-T cells we observed in patients. Using this model, we found ROR1 CAR-T cells did not accumulate in tdLNs and showed faster attrition of Tpex and terminal exhaustion in tumors compared to tumor-specific T cells (TCR-T) that were cultured identically prior to infusion. Tcf1+ CAR-T cells showed greater proliferative capacity, stem-like self-renewal, and tumor control compared to Tcf1- CAR-T cells, suggesting that strategies to preserve Tcf1+ CAR-Ts could significantly improve efficacy. Interestingly, CAR-T cells in tdLNs formed a small reservoir of “pre-exhausted” PD-1-Tcf1+ central memory cells that we could increase by vaccination and that may be able to generate more polyfunctional effectors than Tpex, which are epigenetically committed to producing hypofunctional effectors. We hypothesize that insufficient activation of CAR-T cells by APCs in tdLNs impairs maintenance of stem-like Tpex reservoirs, resulting in less durable tumor control, and that using vaccination to increase reserves of Tcf1+ CAR-T cells in LNs will overcome this barrier. In this proposal, we will use the KP model to determine: 1) whether CAR-T are impaired in maintaining a stem-like Tcf1+ reservoir relative to TCR-T cells and whether this is due to insufficient activation by APCs; and 2) whether activating CAR- T cells with endogenous APCs in LNs via a novel vaccine platform will improve numbers of Tcf1+ CAR-T cells, tumor control, and response to PD-L1 blockade. Our results will reveal whether CAR-T exhaustion in solid tumors is driven in part by impaired Tpex formation and will evaluate a novel vaccine platform to overcome these defects that can be translated to the clinic to enhance the efficacy of CAR-T cells in patients with solid tumors.

项目概要/摘要使用 CAR-T 细胞的免疫疗法在血液恶性肿瘤中引起了显着的反应，但是将这一成功扩展到更常见的上皮癌（死亡率最高），已证明更多在我们进行的一项 1 期试验中，针对肿瘤相关抗原 ROR1 的 CAR-T 细胞诱导。慢性淋巴细胞白血病患者的反应，但在乳房和肺部最终衰竭癌症患者，表明需要保留 CAR-T 功能的策略才能在实体瘤中取得疗效最近的研究表明，PD-1+Tcf1+“前体”耗尽细胞 (Tpex) 的一个子集至关重要。用于介导肿瘤对免疫治疗的成功反应，Tpex 保留了类似干细胞的自我更新能力，增殖和分化为效应样细胞的能力。与抗原呈递细胞 (APC) 一起存在并驻留在肿瘤引流淋巴结 (tdLN) 中，它们可能在那里免受肿瘤中导致终末衰竭的因素的影响，例如更多的慢性抗原刺激、mTOR 与传统 T 细胞不同，CAR-T 细胞由表达的完整抗原激活。肿瘤细胞，而不是通过在肿瘤细胞和 APC 上表达的肽/MHC 复合物，这种设计限制了 CAR-。 T 激活专门针对肿瘤，相对于 tdLN，肿瘤中干细胞样特性的保存可能会受到损害。为了测试这一点，我们开发了 ROR1+ 肺癌的 Kras/p53 (KP) 本土模型，该模型概括了我们在患者中观察到 ROR1 CAR-T 细胞功能障碍，我们发现 ROR1 CAR-T 细胞确实存在功能障碍。与相比，Tpex 不会在 tdLN 中积聚，并且在肿瘤中表现出更快的 Tpex 消耗和终末耗竭在输注之前进行相同培养的肿瘤特异性 T 细胞 (TCR-T) 显示出更大的 Tcf1+ CAR-T 细胞。与 Tcf1-CAR-T 细胞相比，其具有增殖能力、干细胞样自我更新和肿瘤控制能力，这表明保留 Tcf1+ CAR-T 的策略可以显着提高疗效。形成了一个“预先耗尽的”PD-1-Tcf1+中央记忆细胞的小水库，我们可以通过增加疫苗接种，可能能够产生比 Tpex 更多的多功能效应器，这些效应器在表观遗传上我们致力于生产功能低下的效应器，通过以下方式捕获 CAR-T 细胞的激活不足。 tdLN 中的 APC 损害了茎状 Tpex 储存库的维持，导致肿瘤控制的持久性较差，并且使用疫苗接种来增加 LN 中 Tcf1+ CAR-T 细胞的储备将克服这一障碍。我们将使用 KP 模型来确定：1）CAR-T 在维持茎状 Tcf1+ 储存库方面是否受到损害相对于 TCR-T 细胞，这是否是由于 APC 激活不足所致；2) 是否激活 CAR- 通过新型疫苗平台，LN 中具有内源性 APC 的 T 细胞将提高 Tcf1+ CAR-T 细胞的数量，肿瘤控制以及对 PD-L1 阻断的反应我们的结果将揭示实体瘤中 CAR-T 是否耗尽。部分原因是 Tpex 形成受损，并将评估一种新型疫苗平台来克服这些缺陷可以转化为临床，以增强 CAR-T 细胞对实体瘤患者的疗效。