Li Ru, Li Xia, Li Ping, Yao Zhong-qiang, Guo Jia-long, Li Zhan-guo
Department of Rheumatology and Immunology, Peking University People's Hospital, Beijing 100044, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2006 Aug 18;38(4):360-4.
To evaluate the effect of multiple amino acid substitutions of C II 263-272 peptide on collagen-induced arthritis, and explore a therapeutic strategy of rheumatoid arthritis.
A panel of altered C II 263-272 peptides was synthesized with substitutions of TCR-contact residues of C II 263-272 with alanine. The competitive inhibition of APL to wild type C II 263-272 was analyzed by 3H incorporation assay. CIA model was induced by intradermal injection of bovine CII. Altered CII peptide was injected subcutaneously in different doses (1, 10, 100 microg, respectively, twice per week) after onset of CIA. The arthritis index, radiologic and histologic scores were recorded to evaluate the severity change of arthritis. Serum levels of IFN-gamma were examined by ELISA.
Competitive inhibition to wild type C II 263-272 of the altered C II 263-272 peptides (APL1, APL2, APL3) was found in PBMC from RA patients. Among them, APL3 with substitution of residues 267(Q), 270(K) and 271(G) to A showed the most significant effect and thus was used in the treatment of CIA rats. We observed significantly reduced arthritis scores in CIA rats treated with 100 microg/dose of APL as compared with rats treated with PBS and peptide control. The mean radiographic and histologic scores was also markedly lower in APL-treated CIA rats than in PBS or peptide control-treated rats. On day 35 after immunization, the serum level of IFN-gamma in rats was examined and a significantly low level of serum IFN-gamma was found in APL-treated rats.
C II 263-272 peptide with TCR-contact residues substitutions inhibited joint destruction in CIA rats and down-regulated IFN-gamma production, suggesting that altered CII peptide might be potentially therapeutic in rheumatoid arthritis.
评估C II 263 - 272肽的多个氨基酸替换对胶原诱导性关节炎的影响，并探索类风湿关节炎的治疗策略。
合成一组C II 263 - 272肽变体，将C II 263 - 272的TCR接触残基替换为丙氨酸。通过3H掺入试验分析APL对野生型C II 263 - 272的竞争性抑制作用。通过皮内注射牛CII诱导CIA模型。CIA发病后，以不同剂量（分别为1、10、100μg，每周两次）皮下注射改变后的CII肽。记录关节炎指数、放射学和组织学评分，以评估关节炎严重程度的变化。通过ELISA检测血清IFN-γ水平。
在类风湿关节炎患者的外周血单个核细胞中发现了改变后的C II 263 - 272肽（APL1、APL2、APL3）对野生型C II 263 - 272的竞争性抑制作用。其中，将267（Q）、270（K）和271（G）残基替换为丙氨酸的APL3显示出最显著的效果，因此用于治疗CIA大鼠。与用PBS和肽对照处理的大鼠相比，我们观察到用100μg/剂量的APL处理的CIA大鼠的关节炎评分显著降低。APL处理的CIA大鼠的平均放射学和组织学评分也明显低于PBS或肽对照处理的大鼠。免疫后第35天，检测大鼠血清IFN-γ水平，发现APL处理的大鼠血清IFN-γ水平显著降低。
具有TCR接触残基替换的C II 263 - 272肽抑制了CIA大鼠的关节破坏并下调了IFN-γ的产生，表明改变后的CII肽可能对类风湿关节炎具有潜在的治疗作用。
