合成环瓜氨酸蛋白短肽诱导猕猴类风湿关节炎模型的研究

Study on rhesus monkeys′ model of rheumatoid arthritis induced by a synthetic cyclic citrullinated peptide

目的:研究以瓜氨酸蛋白短肽作为抗原制作猕猴关节炎模型的可行性,并从关节炎表现、影像学、免疫应答、组织病理学等方面与经典胶原诱导型关节炎模型进行比较。方法:8只猕猴随机分2组,分别以Ⅱ型胶原(CIA)和偶联血蓝蛋白的环瓜氨酸化波形蛋白短肽(CCit-Vim+KLH,CCV+K-IA)进行免疫。连续观察猕猴的关节炎体征及炎症指标;第4周与第8周分别进行四肢关节的影像学检查(X线、关节B超);第12周处死后行关节组织病理学检查。结果:CCV+K-IA与CIA猕猴关节炎发病率为3/4和4/4,CCV+K-IA组关节炎出现在免疫后第6周,关节炎程度及发生部位同CIA组;CCV+K-IA组产生的抗CCit-Vim抗体、IL-6水平均高于CIA组(P=0.0315;P=0.0335),而抗CCP抗体、抗CⅡ抗体、TNF-α水平差异无统计学意义(P>0.05);影像学结果显示,免疫后第8周两组X线sharp评分、关节超声滑膜炎分级较第4周均有升高,但同期两组比较差异无统计学意义;病理滑膜炎半定量评分显示,CCV+K-IA组与CIA组比较差异无统计学意义。结论:偶联KLH的CCit-Vim短肽能诱导猕猴发生关节炎,并产生较CIA更高的抗CCit-Vim抗体应答。

Objective: To establish a new arthritis model in rhesus monkeys induced by synthetic cyclic citrullinated peptide,and compared with the type Ⅱ collagen-induced arthritis model from the aspects of arthritis signs,imaging,immunology response and histopathology. Methods: 8 rhesus monkeys were randomly divided into two groups and immunized with collagen type Ⅱ(C Ⅱ,CIA) and cyclic citrullinated peptide (CCit-Vim+KLH,CCV+K-IA) coupled with hemocyanin (KLH) respectively.The signs and inflammation indexes of macaques were observed continuously.The imaging examination of the joints of the extremities (X-ray,joint B-ultrasound) was performed at the 4th week and the 8th week.The joint histopathological examination was performed after the 12th week. Results: The incidence of rhesus monkey arthritis in CCV+K-IA and CIA groups was 3/4 and 4/4.Arthritis in CCV+K-IA group appeared at the 6th week after immunization.The severity and location of arthritis were the same as CIA group.The levels of anti-CCit-Vim and IL-6 in CCV+K-IA group were higher than those in CIA group( P =0.031 5;P =0.033 5),but there was no significant difference in the levels of anti-CCP antibody,anti-CⅡ antibody and TNF-α( P >0.05).The results showed that the X-ray sharp score and joint ultrasound synovitis in both groups were higher in the 8th week than in the 4th week,but there was no significant difference between the two groups at the same time.The pathological synovitis semi-quantitative score showed that there was no significant difference between CCV+K-IA and CIA groups. Conclusion: The cyclic citrullinated peptide conjugated KLH can induce arthritis in rhesus monkeys and induce higher levels of anti-CCit-Vim antibodies than CIA.