Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Int J Mol Sci. 2021 Mar 1;22(5):2476. doi: 10.3390/ijms22052476.
T cells that are genetically engineered to express chimeric antigen receptor (CAR) have a strong potential to eliminate tumor cells, yet the CAR-T cells may also induce severe side effects due to an excessive immune response. Although optimization of the CAR structure is expected to improve the efficacy and toxicity of CAR-T cells, the relationship between CAR structure and CAR-T cell functions remains unclear. Here, we constructed second-generation CARs incorporating a signal transduction domain (STD) derived from CD3ζ and a 2nd STD derived from CD28, CD278, CD27, CD134, or CD137, and investigated the impact of the STD structure and signaling on CAR-T cell functions. Cytokine secretion of CAR-T cells was enhanced by 2nd STD signaling. T cells expressing CAR with CD278-STD or CD137-STD proliferated in an antigen-independent manner by their STD tonic signaling. CAR-T cells incorporating CD28-STD or CD278-STD between TMD and CD3ζ-STD showed higher cytotoxicity than first-generation CAR or second-generation CARs with other 2nd STDs. The potent cytotoxicity of these CAR-T cells was not affected by inhibiting the 2nd STD signals, but was eliminated by placing the STDs after the CD3ζ-STD. Our data highlighted that CAR activity was affected by STD structure as well as by 2nd STD signaling.
经基因工程改造表达嵌合抗原受体 (CAR) 的 T 细胞具有强大的消除肿瘤细胞的潜力，但由于过度的免疫反应，CAR-T 细胞也可能引起严重的副作用。虽然优化 CAR 结构有望提高 CAR-T 细胞的疗效和毒性，但 CAR 结构与 CAR-T 细胞功能之间的关系尚不清楚。在这里，我们构建了第二代 CAR，其中包含源自 CD3ζ 的信号转导结构域 (STD) 和源自 CD28、CD278、CD27、CD134 或 CD137 的第二个 STD，并研究了 STD 结构和信号对 CAR-T 细胞功能的影响。第二信号转导结构域的信号增强了 CAR-T 细胞的细胞因子分泌。通过其 STD 持续信号，表达带有 CD278-STD 或 CD137-STD 的 CAR 的 T 细胞以抗原非依赖性方式增殖。在跨膜结构域 (TMD) 和 CD3ζ-STD 之间包含 CD28-STD 或 CD278-STD 的 CAR-T 细胞比第一代 CAR 或具有其他第二信号转导结构域的第二代 CAR 显示出更高的细胞毒性。这些 CAR-T 细胞的强大细胞毒性不受抑制第二信号转导结构域信号的影响，但通过将信号转导结构域放置在 CD3ζ-STD 之后而被消除。我们的数据强调了 CAR 活性受 STD 结构以及第二信号转导结构域信号的影响。
