Department of Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.
Ann Rheum Dis. 2021 Feb;80(2):176-184. doi: 10.1136/annrheumdis-2020-217844. Epub 2020 Sep 30.
Autoreactive B cells play a crucial role in the pathogenesis of rheumatoid arthritis (RA), and B cell-depleting therapies using an antibodies, such as rituximab, have been suggested to be effective in RA treatment. However, transient B cell depletion with rituximab is associated with significant safety challenges related to global suppression of the immune system and thus increases the risks of infection and cancer development. To address selective and persistent issues associated with RA therapy, we developed a customised therapeutic strategy employing universal antifluorescein isothiocyanate (FITC) chimeric antigen receptor T cells (CAR-T cells) combined with FITC-labelled antigenic peptide epitopes to eliminate autoreactive B cell subsets recognising these antigens in RA.
For a proof-of-concept study, four citrullinated peptide epitopes derived from citrullinated autoantigens, namely, citrullinated vimentin, citrullinated type II collagen, citrullinated fibrinogen and tenascin-C, and a cyclocitrulline peptide-1 were selected as ligands for targeting autoreactive B cells; Engineered T cells expressing a fixed anti-FITC CAR were constructed and applied as a universal CAR-T cell system to specifically eliminate these protein-specific autoreactive B cells via recognition of the aforementioned FITC-labelled autoantigenic peptide epitopes.
We demonstrated that anti-FITC CAR-T cells could be specifically redirected and kill hybridoma cells generated by immunisation with antigenic peptides, and autoreactive B cell subsets from RA patients via recognition of corresponding FITC-labelled citrullinated peptide epitopes. Additionally, the cytotoxicity of the CAR-T cells was dependent on the presence of the peptides and occurred in a dose-dependent manner.
The approach described here provides a direction for precise, customised approaches to treat RA and can likely be applied to other systemic autoimmune diseases.
自身反应性 B 细胞在类风湿关节炎（RA）的发病机制中发挥着关键作用，使用抗体（如利妥昔单抗）进行 B 细胞耗竭疗法已被证明对 RA 治疗有效。然而，利妥昔单抗引起的短暂 B 细胞耗竭与免疫系统的全面抑制相关的重大安全挑战有关，从而增加了感染和癌症发展的风险。为了解决与 RA 治疗相关的选择性和持久性问题，我们开发了一种定制的治疗策略，该策略采用通用抗荧光素异硫氰酸酯（FITC）嵌合抗原受体 T 细胞（CAR-T 细胞）与 FITC 标记的抗原肽表位结合，以消除识别这些抗原的 RA 中的自身反应性 B 细胞亚群。
为了进行概念验证研究，选择了四个源自瓜氨酸化自身抗原的瓜氨酸化肽表位，即瓜氨酸化波形蛋白、瓜氨酸化 II 型胶原、瓜氨酸化纤维蛋白原和 tenascin-C 以及环瓜氨酸肽-1 作为靶向自身反应性 B 细胞的配体；构建了表达固定抗-FITC CAR 的工程 T 细胞，并将其用作通用 CAR-T 细胞系统，通过识别上述 FITC 标记的自身抗原肽表位特异性地消除这些蛋白特异性自身反应性 B 细胞。
我们证明，抗-FITC CAR-T 细胞可以通过识别相应的 FITC 标记的瓜氨酸化肽表位，特异性地重定向和杀死用抗原肽免疫产生的杂交瘤细胞以及 RA 患者的自身反应性 B 细胞亚群。此外，CAR-T 细胞的细胞毒性依赖于肽的存在并且呈剂量依赖性。
这里描述的方法为精确、定制的 RA 治疗方法提供了一个方向，并且可能适用于其他系统性自身免疫性疾病。
