Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, Texas, USA.
J Immunother Cancer. 2022 Mar;10(3). doi: 10.1136/jitc-2021-004035.
The current therapeutic antibodies and chimeric antigen receptor (CAR) T cells are capable of recognizing surface antigens, but not of intracellular proteins, thus limiting the target coverage for drug development. To mimic the feature of T-cell receptor (TCR) that recognizes the complex of major histocompatibility class I and peptide on the cell surface derived from the processed intracellular antigen, we used NY-ESO-1, a cancer-testis antigen, to develop a TCR-like fully human IgG1 antibody and its derivative, CAR-T cells, for cancer immunotherapy.
Human single-chain variable antibody fragment (scFv) phage library (~10) was screened against HLA-A2/NY-ESO-1 (peptide 157-165) complex to obtain target-specific antibodies. The specificity and affinity of those antibodies were characterized by flow cytometry, ELISA, biolayer interferometry, and confocal imaging. The biological functions of CAR-T cells were evaluated against target tumor cells in vitro. In vivo antitumor activity was investigated in a triple-negative breast cancer (TNBC) model and primary melanoma tumor model in immunocompromised mice.
Monoclonal antibody 2D2 identified from phage-displayed library specifically bound to NY-ESO-1 in the context of human leukocyte antigen HLA-A*02:01 but not to non-A2 or NY-ESO-1 negative cells. The second-generation CAR-T cells engineered from 2D2 specifically recognized and eliminated A2+/NY-ESO-1+tumor cells in vitro, inhibited tumor growth, and prolonged the overall survival of mice in TNBC and primary melanoma tumor model in vivo.
This study showed the specificity of the antibody identified from human scFv phage library and demonstrated the potential antitumor activity by TCR-like CAR-T cells both in vitro and in vivo, warranting further preclinical and clinical evaluation of the TCR-like antibody in patients. The generation of TCR-like antibody and its CAR-T cells provides the state-of-the-art platform and proof-of-concept validation to broaden the scope of target antigen recognition and sheds light on the development of novel therapeutics for cancer immunotherapy.
目前的治疗性抗体和嵌合抗原受体 (CAR) T 细胞能够识别表面抗原，但不能识别细胞内蛋白，从而限制了药物开发的靶标范围。为了模拟 T 细胞受体 (TCR) 识别细胞表面上主要组织相容性复合体 I 和源自细胞内抗原加工的肽复合物的特征，我们使用 NY-ESO-1，一种癌症-睾丸抗原，开发了一种 TCR 样全人源 IgG1 抗体及其衍生物 CAR-T 细胞，用于癌症免疫治疗。
针对 HLA-A2/NY-ESO-1（肽 157-165）复合物，用噬菌体展示文库 (~10) 筛选人源单链可变抗体片段 (scFv)，以获得针对特定靶标的抗体。通过流式细胞术、ELISA、生物层干涉测量和共聚焦成像来鉴定这些抗体的特异性和亲和力。在体外针对靶肿瘤细胞评估 CAR-T 细胞的生物学功能。在免疫缺陷小鼠的三阴性乳腺癌 (TNBC) 模型和原发性黑色素瘤肿瘤模型中研究体内抗肿瘤活性。
从噬菌体展示文库中鉴定出的单克隆抗体 2D2 特异性结合人类白细胞抗原 HLA-A*02:01 背景下的 NY-ESO-1，但不结合非 A2 或 NY-ESO-1 阴性细胞。从 2D2 工程化的第二代 CAR-T 细胞特异性识别和消除体外 A2+/NY-ESO-1+肿瘤细胞，抑制肿瘤生长，并延长 TNBC 和原发性黑色素瘤肿瘤模型中小鼠的总生存期。
本研究显示了从人 scFv 噬菌体文库中鉴定出的抗体的特异性，并证明了 TCR 样 CAR-T 细胞在体外和体内的潜在抗肿瘤活性，这为进一步在患者中评估 TCR 样抗体的临床前和临床评估提供了依据。TCR 样抗体及其 CAR-T 细胞的产生提供了最先进的平台和概念验证，拓宽了靶抗原识别范围，并为癌症免疫治疗的新型治疗方法的发展提供了启示。
