Translational Research and Development, Lentigen, a Miltenyi Biotec Company, 1201 Clopper Road, Gaithersburg, MD 20878, USA; Research and Development, Miltenyi Biotec, Friedrich-Ebert-Strasse 68, 51429 Bergisch Gladbach, Germany.
Translational Research and Development, Lentigen, a Miltenyi Biotec Company, 1201 Clopper Road, Gaithersburg, MD 20878, USA.
Mol Ther. 2021 Sep 1;29(9):2691-2706. doi: 10.1016/j.ymthe.2021.05.006. Epub 2021 May 8.
Chimeric antigen receptor (CAR) T cells typically use a strong constitutive promoter to ensure maximal long-term CAR expression. However, recent evidence suggests that restricting the timing and magnitude of CAR expression is functionally beneficial, whereas constitutive CAR activation may lead to exhaustion and loss of function. We created a self-driving CD19-targeting CAR, which regulates its own function based on the presence of a CD19 antigen engaged by the CAR itself, by placing self-driving CAR19 constructs under transcriptional control of synthetic activator protein 1 (AP1)-nuclear factor κB (NF-κB) or signal transducer and activator of transcription (STAT)5 promoters. CD19 antigen-regulated expression was observed for self-driving AP1-NFκB-CAR19, with CAR19 upregulation within 18 h after exposure to target CD19, and corresponded to the level of tumor burden. Self-driving CAR-T cells showed enhanced tumor-dependent activation, expansion, and low exhaustion in vitro as compared to constitutively expressed EF1α and murine stem cell virus (MSCV) CARs and mediated tumor regression and survival in Raji-bearing NOD.Cg-PrkdcIl2rg/SzJ (NSG) mice. Long-term CAR function correlated with upregulated CAR expression within 24 h of exposure to tumor antigen. The self-driving AP1-NFκB-CAR19 circuit was also used to inducibly express dominant-negative transforming growth factor β receptor II (TGFBRIIdn), which effectively countered the negative effects of TGF-β on CAR-T activation. Thus, a self-driving CAR approach may offer a new modality to express CAR and auxiliary proteins by enhancing CAR-T functional activity and limiting exhaustion.
嵌合抗原受体 (CAR) T 细胞通常使用强组成型启动子以确保最大程度的长期 CAR 表达。然而，最近的证据表明，限制 CAR 表达的时间和幅度在功能上是有益的，而组成型 CAR 激活可能导致衰竭和功能丧失。我们创建了一种自我驱动的 CD19 靶向 CAR，该 CAR 通过将自身的 CAR 与 CD19 抗原结合来调节自身的功能，方法是将自我驱动的 CAR19 构建体置于合成激活蛋白 1 (AP1)-核因子 κB (NF-κB) 或信号转导和转录激活因子 (STAT)5 启动子的转录控制之下。观察到自我驱动的 AP1-NFκB-CAR19 进行 CD19 抗原调节表达，在暴露于靶标 CD19 后 18 小时内 CAR19 上调，并且与肿瘤负担水平相对应。与组成型表达的 EF1α 和鼠干细胞病毒 (MSCV) CAR 相比，自我驱动的 CAR-T 细胞在体外显示出增强的肿瘤依赖性激活、扩增和低衰竭，并且在携带 Raji 的 NOD.Cg-PrkdcIl2rg/SzJ (NSG) 小鼠中介导肿瘤消退和存活。长期的 CAR 功能与暴露于肿瘤抗原后 24 小时内上调的 CAR 表达相关。自我驱动的 AP1-NFκB-CAR19 电路也用于诱导表达显性阴性转化生长因子 β 受体 II (TGFBRIIdn)，这有效地抵消了 TGF-β 对 CAR-T 激活的负面影响。因此，自我驱动的 CAR 方法可以通过增强 CAR-T 功能活性和限制衰竭来提供一种新的表达 CAR 和辅助蛋白的方式。
