In this study, we investigated CD70 as a promising target for renal cell carcinoma (RCC) therapy and developed a potent chimeric antigen receptor T (CAR-T) cells for potential clinical testing. CD70, found to be highly expressed in RCC tumors, was associated with decreased survival. We generated CAR-T cells expressing VHH sequence of various novel nanobodies from immunized alpaca and a single-chain variable fragment (scFv) derived from human antibody (41D12). In our in vitro experiments, anti-CD70 CAR-T cells effectively eliminated CD70-positive tumor cells while sparing CD70-negative cells. The nanobody-based CAR-T cells demonstrated significantly higher production of cytokines such as IL-2, IFN-γ and TNF-ɑ during co-culture, indicating their potential for enhanced functionality. In xenograft mouse model, these CAR-T cells exhibited remarkable anti-tumor activity, leading to the eradication of RCC tumor cells. Importantly, human T cell expansion after infusion was significantly higher in the VHH groups compared to the scFv CAR-T group. Upon re-challenging mice with RCC tumor cells, the VHH CAR-T treated group remained tumor-free, suggesting a robust and long-lasting anti-tumor response. These findings provide strong support for the potential of nanobody-based CD70 CAR-T cells as a promising therapeutic option for RCC. This warrants further development and consideration for future clinical trials and applications.

中文翻译：

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开发针对 CD70 的嵌合抗原受体 T 细胞用于治疗肾细胞癌

在这项研究中，我们研究了 CD70 作为肾细胞癌 (RCC) 治疗的一个有前景的靶点，并开发了一种有效的嵌合抗原受体 T (CAR-T) 细胞用于潜在的临床测试。 CD70 在 RCC 肿瘤中高表达，与生存率降低相关。我们生成了表达来自免疫羊驼的各种新型纳米抗体的 VHH 序列和源自人抗体 (41D12) 的单链可变片段 (scFv) 的 CAR-T 细胞。在我们的体外实验中，抗CD70 CAR-T细胞有效地消除了CD70阳性肿瘤细胞，同时保留了CD70阴性细胞。基于纳米抗体的 CAR-T 细胞在共培养过程中表现出显着更高的细胞因子产量，例如 IL-2、IFN-γ 和 TNF-ɑ，表明它们具有增强功能的潜力。在异种移植小鼠模型中，这些 CAR-T 细胞表现出显着的抗肿瘤活性，从而消除了 RCC 肿瘤细胞。重要的是，与 scFv CAR-T 组相比，VHH 组输注后的人类 T 细胞扩增显着更高。用 RCC 肿瘤细胞重新攻击小鼠后，VHH CAR-T 治疗组仍然没有肿瘤，这表明具有强大且持久的抗肿瘤反应。这些发现为基于纳米抗体的 CD70 CAR-T 细胞作为 RCC 有前景的治疗选择的潜力提供了强有力的支持。这值得进一步开发并考虑未来的临床试验和应用。