Cyrus Tang Medical Institute, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, China.
PersonGen BioTherapeutics (Suzhou) Co., Ltd., Suzhou, China.
Eur J Haematol. 2024 Jan;112(1):64-74. doi: 10.1111/ejh.14090. Epub 2023 Sep 6.
Despite the great success of CD19 CAR-T cell therapy, its clinical efficacy has been greatly hampered by the high relapse rate. In this study, we designed and compared four structures of CD19/CD22 bispecific CAR-T cells with different linkers and different orders of the antibody sequences.
We detected the cytotoxicity, cytokine secretion levels, sustainable killing ability, differentiation, exhaustion of these four CAR-T cells in vitro. The optimal Bis-C CAR-T cells were evaluated the efficacy using NSG mice.
The two structures of CD19/CD22 bispecific CAR-T cells using (EAAAK)3 as linker had more significant cytotoxicity and cytokine secretion levels. In the process of continuous killing, Bis-C CAR-T cells showed better sustained killing ability, memory phenotype differentiation, and exhaustion. In the in vivo experiment mimicking CD19-negative relapse, Bis-C CAR-T was more able to control the tumor progression of mice in the CD19 low expression or no expression groups than CD19 CAR-T.
This study has generated a novel bispecific CAR-T cell that can simultaneously target CD19 or CD22 positive tumor cells, providing a new strategy to address the limitations of single-targeted CAR-T therapy in B-cell tumors (limited response or relapse).
尽管 CD19 CAR-T 细胞疗法取得了巨大成功，但由于复发率高，其临床疗效受到了极大的限制。在这项研究中，我们设计并比较了四种不同连接子和不同抗体序列顺序的 CD19/CD22 双特异性 CAR-T 细胞结构。
我们在体外检测了这四种 CAR-T 细胞的细胞毒性、细胞因子分泌水平、持续杀伤能力、分化和耗竭情况。使用 NSG 小鼠评估最佳 Bis-C CAR-T 细胞的疗效。
使用 (EAAAK)3 作为连接子的两种 CD19/CD22 双特异性 CAR-T 细胞具有更强的细胞毒性和细胞因子分泌水平。在连续杀伤过程中，Bis-C CAR-T 细胞表现出更好的持续杀伤能力、记忆表型分化和耗竭。在模拟 CD19 阴性复发的体内实验中，与 CD19 CAR-T 相比，Bis-C CAR-T 能够更好地控制低表达或无表达 CD19 组小鼠的肿瘤进展。
本研究产生了一种新型的双特异性 CAR-T 细胞，能够同时靶向 CD19 或 CD22 阳性肿瘤细胞，为解决 B 细胞肿瘤中单一靶向 CAR-T 治疗的局限性（应答有限或复发）提供了新策略。
