Chimeric antigen receptors (CARs) are modular proteins capable of redirecting immune cells toward a wide variety of disease-associated antigens. Here, we explore the effects of CAR protein sequence and structure on CAR-T cell function. Based on the empirical observation that CD20 CARs with similar sequences exhibit divergent tonic-signaling and anti-tumor activities, we devised engineering strategies that aimed to improve CAR-T cell function by tuning the intensity of tonic signaling. We found that CARs designed to exhibit low but non-zero levels of tonic signaling show robust effector function upon antigen stimulation while avoiding premature functional exhaustion by CAR-T cells. Through alterations of the ligand-binding domain sequence and overall conformation of the CAR protein, we generated CD20 CAR variants that outperform the CD19 CAR in mouse models of human lymphoma. We further demonstrate that rational modification of protein confirmation can be generalized to improve GD2 CAR-T cell efficacy against neuroblastoma. These findings point to tonic signaling and basal T-cell activation as informative parameters to guide the rational design of next-generation CARs for cancer therapy.

中文翻译：

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合理调整汽车补品信号产生了针对癌症的卓越T细胞疗法

嵌合抗原受体（CARs）是一种模块化蛋白质，能够将免疫细胞重定向至多种与疾病相关的抗原。在这里，我们探讨了CAR蛋白序列和结构对CAR-T细胞功能的影响。基于对具有相似序列的CD20 CARs表现出不同的强直信号和抗肿瘤活性的经验观察，我们设计了旨在通过调节强直信号强度来改善CAR-T细胞功能的工程策略。我们发现，设计为显示低水平但非零水平的强直信号的CAR在抗原刺激后显示强大的效应子功能，同时避免了CAR-T细胞过早的功能衰竭。通过改变配体结合域序列和CAR蛋白的整体构象，我们在人类淋巴瘤小鼠模型中产生了优于CD19 CAR的CD20 CAR变体。我们进一步证明了蛋白质确认的合理修饰可以被普遍用来提高GD2 CAR-T细胞对抗神经母细胞瘤的功效。这些发现表明，进补信号和基础T细胞活化是指导癌症治疗的下一代CAR合理设计的信息参数。