Jiang Fu-Yao, Zhang Yan-Zhu, Tai Yuan-Hong, Chou Chien-Yu, Hsieh Yu-Ching, Chang Ya-Chi, Huang Hsiao-Chen, Li Zhi-Qin, Hsieh Yuan-Chin, Chen I-Ju, Huang Bo-Cheng, Su Yu-Cheng, Lin Wen-Wei, Lin Hsin-Chieh, Chao Jui-I, Yuan Shyng-Shiou F, Wang Yun-Ming, Cheng Tian-Lu, Tzou Shey-Cherng
Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China.
Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China.
Inflamm Regen. 2023 Feb 16;43(1):13. doi: 10.1186/s41232-023-00264-8.
CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment.
We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis.
Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice.
Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.
CTLA4Ig是一种细胞毒性T淋巴细胞相关蛋白4（CTLA4）的胞外结构域与人IgG的Fc（Ig）片段的二聚体融合蛋白，已被批准用于治疗类风湿性关节炎。然而，CTLA4Ig可能会引起不良反应。开发一种病变选择性的CTLA4Ig变体可能会在维持治疗效果的同时提高安全性。
我们通过基质金属蛋白酶（MMP）的底物序列将白蛋白连接到CTLA4Ig的N端（称为Alb-CTLA4Ig）。通过基于细胞的ELISA和体外Jurkat T细胞活化试验分析MMP消化前后Alb-CTLA4Ig的结合活性和生物学活性。在小鼠胶原诱导的关节炎中测试了Alb-CTLA4Ig治疗关节炎症的疗效和安全性。
Alb-CTLA4Ig在生理条件下稳定且无活性，但可被MMPs完全激活。未消化的Alb-CTLA4Ig的结合活性比MMP消化后的Alb-CTLA4Ig至少弱10000倍。未消化的Alb-CTLA4Ig无法抑制Jurkat T细胞活化，而MMP消化后的Alb-CTLA4Ig在抑制T细胞方面与传统CTLA4Ig一样有效。Alb-CTLA4Ig在炎症关节中转化为CTLA4Ig以治疗小鼠胶原诱导的关节炎，显示出与传统CTLA4Ig相似的疗效。与传统CTLA4Ig不同，Alb-CTLA4Ig不会抑制治疗小鼠脾脏中的抗菌反应。
我们的研究表明，Alb-CTLA4Ig可被MMPs激活以原位抑制组织炎症。因此，Alb-CTLA4Ig是治疗小鼠胶原诱导性关节炎的一种安全有效的方法。
