Attacking the Immunopeptidome of Ewing Sarcoma

攻击尤文肉瘤的免疫肽组

• 批准号: 10714230
• 负责人: Sabine Heitzeneder
• 金额: $ 46.74万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-11 至 2028-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10714230
• 关键词: Address; Adoptive Cell Transfers; Adoptive Transfer; Adult; Affinity; Antigens; Autoantigens; Binding; Binding Proteins; Bone neoplasms; CRISPR/Cas technology; Cancer Burden; Cancer Etiology; Chemoresistance; Child; Childhood Solid Neoplasm; Data; Dendritic Cells; Development; Disease; Dose; Engineering; Ewings sarcoma; HLA-A2 Antigen; IGF2 gene; Immune Targeting; Immune Tolerance; Immune response; Immune system; Immunotherapeutic agent; Immunotherapy; Incidence; Individual; Knock-out; Knowledge; Late Effects; Lead; Lipase; Longevity; Malignant Neoplasms; Mediating; Metastatic/Recurrent; Mission; Mutation; Nature; Nonmetastatic; Normal tissue morphology; Oncogenes; Outcome; Patients; Pediatric Neoplasm; Pediatric Oncology; Peptides; Process; Proteins; Public Health; Quality of life; Recurrence; Regimen; Research; Resistance; Risk; Safety; Science; Severities; Signal Transduction; Solid; Solid Neoplasm; Survival Rate; Survivors; T cell therapy; T-Cell Receptor; T-Lymphocyte; Technology; Testing; Therapeutic; Time; Tissues; Toxic effect; Translating; Tumor Antigens; Tumor Cell Derivative Vaccine; United States National Institutes of Health; Variant; Work; antigen-specific T cells; autologous lymphocytes; bench to bedside; cancer cell; candidate identification; checkpoint inhibition; chemotherapy; childhood cancer mortality; chimeric antigen receptor T cells; comparison control; cross reactivity; effector T cell; engineered T cells; exhaustion; experience; fitness; high risk; immunotherapy trials; improved outcome; interest; lead candidate; neoantigens; next generation; novel; novel strategies; novel therapeutics; overexpression; postnatal; prevent; prototype; research clinical testing; screening; targeted treatment; therapeutic candidate; therapeutic evaluation; tumor

PROJECT SUMMARY Solid cancers are a leading cause of cancer related death in children and there is great interest in harnessing recent progress in immunotherapy for the treatment of pediatric solid tumors. Immune checkpoint inhibition (ICI) is the most active form of immunotherapy for adult solid cancers, but ICI is not effective in pediatric solid tumors. This discrepancy is explained by the low mutational burden of pediatric solid tumors, since neoantigens arising from tumor specific mutations are the target of the most potent ICI induced immune responses. Overexpressed non-mutated self-antigens, that are not expressed on normal vital tissues, can serve as the basis for effective immune therapies, but immune tolerance must be overcome to induce potent immune responses to this class of molecules. This project focuses on Ewing Sarcoma (EWS) a prototype low mutation burden solid tumor, for which progress has stalled. Standard therapies for EWS rely on dose intensive regimens largely developed in the 1970s and 80s which leave survivors with severe, lifelong late effects. No targeted therapeutics have been demonstrated to be effective. Few patients with metastatic or recurrent EWS survive. Using immunopeptidome profiling, we discovered novel peptides from lipase-1 (LIPI) and IGF2 binding protein 1 (IGF2BP1) that are presented by HLA-A2+ on EWS. These non-mutant proteins are overexpressed at high levels in the vast majority of EWS and are essentially absent from vital normal tissues, thereby demonstrating a very favorable profile for immune targeting. To translate this discovery into a therapeutic application for EWS, this project applies a workflow we developed to discover, characterize, and engineer T cells receptors (TCRs) targeting these peptides. The major overarching challenge that the project addresses is determining the optimal approach to identify and/or engineer high potency TCRs capable of targeting self-antigens without incurring cross-reactivity that would result in unacceptable toxicity. In Aim 1, we test the hypothesis that TCRs targeting LIPI- and IGF2BP1-derived peptides will be identified in HLA-A2+ hosts but will manifest low potency due to immune tolerance. We will simultaneously discover and compare antigen reactive TCRs present in HLA-A2– hosts, which we predict will be more potent, but may be unsafe due to cross-reactivity. In Aim 2, we use next generation approaches to engineer natural TCRs, identified in HLA-A2+ hosts, into more potent, but safe antigen-specific TCRs, through affinity maturation or catch bond engineering. Given the known risks for cross reactivity of high potency TCRs, next generation engineered TCRs developed here will be closely vetted across several platforms for cross-reactivity. In Aim 3, we use fitness enhancements developed in the Mackall lab to enhance the potency of CAR T cells to enhance the potency of T cells expressing our lead candidate LIPI- and IGF2BP1-reactive TCRs. The work conducted in this project will deliver state-of-the-art therapeutics ready for clinical testing in EWS and provide general understanding regarding the optimal approach to engineer TCRs targeting self- antigens, which will provide value in pediatric oncology and low mutation burden cancers beyond EWS.

项目概要 实体癌是儿童癌症相关死亡的主要原因，人们对利用实体癌非常感兴趣 免疫疗法治疗儿童实体瘤的最新进展。免疫检查点抑制 (ICI) 是治疗成人实体瘤最活跃的免疫疗法，但 ICI 对儿童实体瘤无效。 这种差异可以用儿科实体瘤的低突变负荷来解释，因为新抗原的产生 肿瘤特异性突变是 ICI 诱导的最有效免疫反应的目标。过度表达 非突变自身抗原，不在正常重要组织中表达，可以作为有效的基础 免疫疗法，但必须克服免疫耐受才能诱导对此类药物的有效免疫反应 分子。该项目重点关注尤文肉瘤（EWS），一种原型低突变负荷实体瘤，用于 进展已经停滞。 EWS 的标准疗法依赖于剂量密集型治疗方案，主要开发于 20世纪70年代和80年代给幸存者留下了严重的、终生的后期影响。目前还没有针对性的治疗方法 被证明是有效的。很少有转移性或复发性 EWS 患者能够存活。使用免疫肽组 通过分析，我们发现了来自脂肪酶 1 (LIPI) 和 IGF2 结合蛋白 1 (IGF2BP1) 的新肽，它们 由 HLA-A2+ 在 EWS 上呈现。这些非突变蛋白在绝大多数中高水平过度表达 EWS 的并且在重要的正常组织中基本上不存在，从而表现出非常有利的特征 免疫靶向。为了将这一发现转化为 EWS 的治疗应用，该项目应用了 我们开发的工作流程是为了发现、表征和设计针对这些的 T 细胞受体 (TCR) 肽。该项目解决的主要挑战是确定最佳方法 识别和/或设计能够靶向自身抗原而不引起交叉反应的高效TCR 这将导致不可接受的毒性。在目标 1 中，我们测试了针对 LIPI- 和 IGF2BP1 衍生的肽将在 HLA-A2+ 宿主中被识别，但由于免疫作用而表现出低效力 宽容。我们将同时发现并比较 HLA-A2– 宿主中存在的抗原反应性 TCR，这 我们预测会更有效，但由于交叉反应可能不安全。在目标 2 中，我们使用下一代 将 HLA-A2+ 宿主中鉴定的天然 TCR 改造为更有效但更安全的抗原特异性的方法 TCR，通过亲和力成熟或捕获键工程。鉴于高交叉反应性的已知风险 效力 TCR，这里开发的下一代工程 TCR 将在多个平台上进行严格审查 用于交叉反应。在目标 3 中，我们使用 Mackall 实验室开发的健身增强功能来增强效力 CAR T 细胞增强表达我们的主要候选 LIPI 和 IGF2BP1 反应性的 T 细胞的效力 TCR。该项目中进行的工作将提供最先进的治疗方法，为临床测试做好准备 EWS 并提供关于设计针对自我的 TCR 的最佳方法的一般理解 抗原，这将为儿科肿瘤学和 EWS 之外的低突变负荷癌症提供价值。