中文摘要：

目的：研究以丙氨酸替换Ⅱ型胶原（collagenⅡ，CⅡ）263—272序列中的267、270、271位氨基酸的变构肽鼻黏膜给药对胶原诱导性关节炎（collagen induced arthfitis，CIA）的抑制作用及其作用机制。方法：以牛CⅡ免疫Lewis大鼠诱发CIA。于发病的当天开始给予CⅡ变构肽和原型肽鼻滴入治疗，连续每天给药，5d后，改为隔天给药，空白对照组给予磷酸盐缓冲液（phosphate buffered solution，PBS）。观察关节肿胀情况，记录关节炎评分以及体重的改变。治疗结束后处死大鼠，行后踝关节病理切片，观察关节病理改变。ELISA方法检测血清中抗CⅡ抗体亚型以及细胞因子的变化，流式细胞仪检测外周血CD4^＋CD25^＋T细胞的变化，荧光定量PCR检测脾和淋巴结中Foxp3和TGF—BmRNA的表达水平。结果：（1）CⅡ变构肽可以抑制CIA的发展。实验结束时CⅡ变构肽、原型肽以及PBS组大鼠关节炎评分分别为2．50±2．43、4．50±2．23和6．33±2．73（变构肽治疗组与PBS对照组比较，P〈0．05），各组大鼠后踝关节病理学评分分别为1．33±1．07、2．17±0．94和2．83±0．58，与PBS对照组相比，CⅡ变构肽可以明显抑制CIA关节病变的发展（P〈0．05）。（2）与PBS对照组相比，CⅡ变构肽可以降低CIA大鼠体内抗CⅡ抗体IgG2a亚型的滴度（0．56±0．19和0．95±0，29，P〈0．05）。CⅡ变构肽、原型肽及PBS对照组大鼠血清中γ干扰素（interferon-γ，IFN-γ）水平分别为（185．33±29．77）、（231．62±41．82）和（220．64±83．61）ng／L，与原型肽组相比，CⅡ变构肽可以降低大鼠血清中IFN-γ水平。（3）CⅡ变构肽治疗对调节性T细胞的影响：3组大鼠外周血CD4^＋CD25^＋T细胞占CD4^＋T细胞比例差异无统计学意义，CⅡ变构肽治疗组大鼠脾和淋巴结中Foxp3和转化生长因子B（transforming growth factorsβ，TGF-β）mRNA的表达水平较对照组有升?

英文摘要：

Objective：To evaluate the effect of mucosal administration of altered collagen Ⅱ （C Ⅱ ） 263 -272 peptide （267Q→A, 270K→A and 271G→A） on collagen induced arthritis （CIA）, and to explore the mechanism of the inhibitory effect of the altered CⅡ 263 - 272 peptide on CIA. Methods： CIA was induced in Lewis rats by immunization with bovine CⅡ. Altered C 11263 -272 peptide was given intranasally beginning from the onset of arthritis （ 100 μg/dose, daily for 5 doses and continuing every other day for other 7 doses）. Wild CⅡ263 - 272 peptide （ 100μg/dose） or PBS was administered as controls with the same procedure. Therapeutic effects were evaluated by arthritis scores, body weight change, and joint pathologic scores. The anti-C Ⅱ antibody and its subtypes were measured with ELISA. The cytokines of IFN-γand IL-10 were measured with ELISA. The induction of regulatory T cells was assessed by FACS analysis of percentage of peripheral CD4^＋CD25^＋ T cells, and by real-time PCR analysis of the expression of Foxp3 and TGF-β mRNA. Results： （1） Following treatment with the altered C Ⅱ 263 - 272 peptide, arthiritis scores were reduced and body weight was increased. The mean arthritis scores of rats treated with altered peptide, wild peptide and PBS were 2.50± 2. 43, 4.50 ± 2.23 and 6.33± 2. 73, respectively. The altered peptide could retard the histologic lesion of the joints. （2） The titers of anti-CⅡ antibodies IgG and IgG1 in the three groups were similar, but the IgG2a in altered peptidetreated rats decreased markedly as compared with PBS-treated rats （0. 56 ± 0. 19 vs 0. 95 ± 0. 29, P 〈 0. 05 ）.The serum IFN-γ in rats treated with altered peptide, wild peptide and PBS were （ 185.33±29.77）, （231.62±41.82） and （220.64 ±83.61） ng/L, respectively （P 〈0.05）. No difference was found in the levels of serum IL-10 among the three groups. （3） There was no significant difference in the percentage of peripheral CD4^＋ CD25^＋T cells and t