链球菌CpG DNA对寻常型银屑病患者T细胞活化的影响

The role of CpG DNA from group A beta-hemolytic streptococcus on T cells activation in the patients with psoriasis vulgaris

研究链球菌核酸成分对寻常型银屑病患者T细胞活化的影响。利用层析法去除A型β溶血型链球菌超声粉碎产物中的核酸成分,分别用链球菌全菌抗原(streptococcal antigen,SA)和去除核酸的链球菌抗原(nucleic acid depleted-streptococ-cal antigen,non-NASA)刺激寻常型银屑病患者(20例)和正常人(12例)外周血单个核细胞(PBMC);同时non-NASA联合人工合成的CpG ODN(CpG-A和CpG-B)以及单用CpG ODN刺激患者PBMC(12例),24 h后采用流式细胞术检测并比较总T细胞及皮肤淋巴细胞抗原阳性(CLA+)T细胞活化表达CD69+及患者B细胞活化表达CD86+的百分率的差异。结果显示,在银屑病患者中,SA刺激后总T细胞和CLA+T细胞活化表达CD69+的百分率均高于non-NASA(P=0.012和0.042),而在正常人中两者无统计学差异,且均不激活T细胞表达CD69+(P>0.05);同时non-NASA联合CpG-A刺激患者PBMCs后总T细胞及CLA+T细胞表达CD69+的百分率亦高于non-NASA单独刺激(P=0.031和0.022),但联合CpG-B未发现差异(P>0.05),且CpG-A和B单独刺激对T细胞活化表达CD69+的百分率无影响(P>0.05)。另一方面,SA、non-NASA以及后者联合CpG-A刺激患者B细胞活化表达CD86+的百分率无统计学差异(P>0.05),但non-NASA联合CpG-B刺激可显著增加B细胞CD86+的表达率(P<0.01),同时CpG-B可激活B细胞表达CD86+,CpG-A无此作用。研究表明,去除核酸的链球菌抗原降低银屑病患者总T细胞以及CLA+T细胞的活化,但对B细胞活化无影响,提示链球菌CpG DNA可协同菌体蛋白诱导病理性T细胞的活化,参与银屑病的发生。

To determine the effects of β-hemolytic streptococcal CpG DNA on T cell activation in patients with psoriasis vulgaris, PBMC from 20 patients and 12 healthy controls were stimulated with streptococcal antigens （SA） and streptococcal antigens without nucleic acid （nucleic acid depleted-streptococcal antigen, non-NASA）. Furthermore, PBMC from 12 patients were also stimulated with non-NASA plus CpG ODN （CpG-A/CpG-B） and CpG ODN alone, the detection of activation marker CD69^＋ expressed by whole T cells and CLA^＋ T cells and CD86^＋ expressed by B cells from patients were proceeded. Among psoriatic patients, SA showed significantly higher expression rate of CD69^＋ T cells and CLA^＋ T cells compared with non- NASA （P〈0.05）. The same results were also observed between non-NASA and non-NASA plus CpG-A （P〈0. 05）. However, there was no significant difference between SA and non-NASA among healthy controls （P〉0.05）. Moreover, except that non-NASA plus CpG-B showed significantly higher CD86^＋ expression by B cells （P〈0.05）, such difference was not observed in other groups （P〉0.05）. So streptococcal antigens without nucleic acid could reduce the activation of T cells from the patients, but no effects on B cells. These results indicate that streptococcal CpG DNA may play an important role in the activation of pathogenic T cells, leading to the development of psoriasis.