Semilietof Aikaterini, Stefanidis Evangelos, Gray-Gaillard Elise, Pujol Julien, D'Esposito Alessia, Reichenbach Patrick, Guillaume Philippe, Zoete Vincent, Irving Melita, Michielin Olivier
Swiss Institute of Bioinformatics, Lausanne, Switzerland.
Department of Oncology, Ludwig Institute for Cancer Research Lausanne, University of Lausanne, Epalinges, Switzerland.
J Immunother Cancer. 2024 Dec 22;12(12):e009504. doi: 10.1136/jitc-2024-009504.
The adoptive cell transfer (ACT) of T cell receptor (TCR)-engineered T cells targeting the HLA-A2-restricted epitope NY-ESO-1 (A2/NY) has yielded important clinical responses against several cancers. A variety of approaches are being taken to augment tumor control by ACT including TCR affinity-optimization and T-cell coengineering strategies to address the suppressive tumor microenvironment (TME). Most TCRs of clinical interest are evaluated in immunocompromised mice to enable human T-cell engraftment and do not recapitulate the dynamic interplay that occurs with endogenous immunity in a treated patient. A variety of humanized mouse models have been described but they have limitations in immune reconstitution and are technically challenging to implement. Here, we have developed a chimeric syngeneic tumor model in which A2Kb transgenic C57BL/6 mice are engrafted with B16 expressing A2Kb:NY as a single chain trimer (SCT) and treated by ACT with murine T cells expressing A2/NY TCRs comprising human variable fused to mouse constant regions.
We compared the function of a supraphysiological affinity A2/NY TCR (wtc51m), a computationally designed TCR in an optimal affinity range (DMβ), and a near non-binding TCR (V49I), engineered in both primary human and murine T cells by lentiviral and retroviral transduction, respectively. We evaluated a variety of strategies to stably express A2Kb:NY on the surface of mouse tumor cell lines including B16 melanoma, ultimately achieving success with an SCT comprising human β2m fused by GS linkers to both the NY-peptide and to α1 of the HLA complex. ACT studies were performed in B16-A2Kb:NY tumor-bearing, non-preconditioned immune-competent HLA-A*0201/H-2Kb (A2Kb) transgenic C57BL/6 mice and tumors characterized post-transfer.
We observed significantly improved function of DMβ-T cells as well as superior infiltration and tumor control upon ACT as compared to the control TCR-T cells. Moreover, with our chimeric syngeneic tumor model, we were able to track dynamic and favorable changes in the TME upon DMβ-T cell transfer.
We have developed a robust, simple, and inexpensive preclinical strategy for evaluating human TCRs in the context of a fully competent murine immune system that can aid in the development of coengineered TCR-T cells and combination treatments translated to the clinic.
过继性细胞转移（ACT）工程化T细胞受体（TCR）靶向HLA - A2限制性表位NY - ESO - 1（A2/NY）已在针对多种癌症的治疗中产生了重要的临床反应。人们正在采取多种方法通过ACT增强肿瘤控制，包括TCR亲和力优化和T细胞共工程策略，以应对抑制性肿瘤微环境（TME）。大多数具有临床意义的TCR在免疫缺陷小鼠中进行评估，以实现人类T细胞植入，且无法重现治疗患者体内内源性免疫发生的动态相互作用。已描述了多种人源化小鼠模型，但它们在免疫重建方面存在局限性，且技术实施具有挑战性。在此，我们开发了一种嵌合同基因肿瘤模型，其中A2Kb转基因C57BL/6小鼠植入表达A2Kb:NY作为单链三聚体（SCT）的B16细胞，并通过ACT用表达包含与人可变区融合至小鼠恒定区的A2/NY TCR的鼠T细胞进行治疗。
我们比较了超生理亲和力A2/NY TCR（wtc51m）、在最佳亲和力范围内通过计算设计的TCR（DMβ）以及近乎无结合能力的TCR（V49I）的功能，它们分别通过慢病毒和逆转录病毒转导在原代人T细胞和鼠T细胞中构建。我们评估了多种在小鼠肿瘤细胞系（包括B16黑色素瘤）表面稳定表达A2Kb:NY的策略，最终通过由GS接头将人β2m与NY肽以及HLA复合物的α1融合而成的SCT取得成功。在携带B16 - A2Kb:NY肿瘤、未进行预处理的具有免疫能力的HLA - A*0201/H - 2Kb（A2Kb）转基因C57BL/6小鼠中进行ACT研究，并在转移后对肿瘤进行特征分析。
与对照TCR - T细胞相比，我们观察到DMβ - T细胞的功能显著改善，以及ACT后更好的浸润和肿瘤控制。此外，利用我们的嵌合同基因肿瘤模型，我们能够追踪DMβ - T细胞转移后TME中动态且有利的变化。
我们开发了一种强大、简单且廉价的临床前策略，用于在完全有功能的鼠免疫系统背景下评估人TCR，这有助于开发可转化至临床的共工程化TCR - T细胞和联合治疗方法。
