PO.IM01.08 · 免疫学
源自RenTCR的MAGEA1特异性TCR在体外和体内表现出优越的肽敏感性和强效抗肿瘤活性
RenTCR-derived MAGEA1-specific TCRs demonstrated superior peptide sensitivity and potent antitumor activity in vitro and in vivo
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：MAGEA1是一种癌症-睾丸抗原，在HCC和NSCLC等实体瘤中广泛表达，但在正常组织中仅限于睾丸，使其成为理想的治疗靶点。针对MAGEA1的TCR疗法正处于临床前/早期临床阶段。传统的TCR发现策略通常依赖于从供者PBMCs或患者TILs中分离。相比之下，Biocytogen专有的RenTCR平台能够利用TCR/MHC人源化小鼠模型生成TCR。由于缺乏对人类抗原的胸腺阴性选择，该平台有助于鉴定出表现出更高反应性和特异性的TCR。
方法：用全长MAGEA1 mRNA免疫RenTCR小鼠（HLA-A*02:01）。分离PBMCs或脾细胞，并在体外用呈递MAGEA1的人工修饰抗原呈递细胞（APCs）进行刺激。随后分选激活的抗原特异性CD8+ T细胞。通过FACS分选单细胞以进行逆转录、扩增和测序，从而获得TCR序列。初始TCR筛选使用Jurkat报告基因试验检测结合。将阳性TCR转导入原代人类T细胞，并与HLA-A2.1+/MAGEA1+肿瘤细胞共培养以评估杀伤和细胞因子释放。功能性TCR候选物接受脱靶风险评估，最终使用NDG小鼠的CDX模型验证抗肿瘤疗效。
结果：免疫20只小鼠共产生80个结合阳性的TCR。这些TCR中的大多数在体外介导了强效的细胞毒活性。功能亲和力评估显示，与人类供者来源的TCR相比，源自RenTCR小鼠的TCR以更优越的敏感性识别靶肽。候选TCR中未检测到交叉反应性。所有候选TCR在携带HLA-A2.1+/MAGEA1+肿瘤的NDG小鼠中均通过诱导肿瘤消退而显示出疗效。
结论：RenTCR平台能够生成具有更高反应性和特异性的T细胞受体（TCR）。源自RenTCR小鼠的TCR比人类供者来源的TCR表现出更好的肽敏感性。候选TCR在体外和体内均表现出优异的抗肿瘤活性。
查看英文原文 English abstract
Background: MAGEA1, a cancer-testis antigen, is broadly expressed in solid tumors such as HCC and NSCLC, but is restricted to the testis in normal tissues, making it an ideal therapeutic target. TCR therapies against MAGEA1 are in preclinical/early clinical stages. Conventional strategies for TCR discovery typically rely on isolation from donor PBMCs or patient TILs. In contrast, Biocytogen's proprietary RenTCR platform enables the generation of TCRs using TCR/MHC humanized mouse models. Lacking thymic negative selection to human antigens, this platform facilitates the identification of TCRs exhibiting higher reactivity and specificity.
Method: RenTCR mice (HLA-A*02:01) were immunized with full-length MAGEA1 mRNA. PBMCs or splenocytes were isolated and stimulated in vitro with artificially modified antigen-presenting cells (APCs) presenting MAGEA1. Activated antigen-specific CD8+ T cells were then sorted. Single cells were sorted by FACS for reverse transcription, amplification, and sequencing to obtain TCR sequences. Initial TCR screening used a Jurkat reporter assay for binding. Positive TCRs were transduced into primary human T cells and co-cultured with HLA-A2.1+/MAGEA1+ tumor cells to assess killing and cytokine release. Functional TCR candidates underwent off-target risk assessment, with final anti-tumor efficacy validated in CDX models using NDG mice.
Results: Immunization of 20 mice yielded a total of 80 binding-positive TCRs. The majority of these TCRs mediated potent cytotoxic activity in vitro . Assessment of functional avidity showed that TCRs derived from RenTCR mice recognized target peptides with superior sensitivity compared to human donor-derived TCRs. No cross-reactivity was detected in the candidate TCRs. All candidate TCRs demonstrated efficacy by inducing tumor regression in NDG mice bearing HLA-A2.1+/MAGEA1+ tumors.
Conclusion: The RenTCR platform enables the generation of T cell receptors (TCRs) with higher reactivity and specificity. TCRs derived from RenTCR mice exhibited better peptide sensitivity than human donor-derived TCRs. The candidate TCRs demonstrated excellent antitumor activity both in vitro and in vivo .
利益披露 Disclosure
Y. Yang, None..
Y. Zhang, None..
J. Yao, None.