链球菌M蛋白同源角蛋白多肽在银屑病发病中的作用

摘要

Objective To study the role of the keratin peptides homologous with M protein in the pathogenesis of psoriasis. Methods Keratin peptides homologous to M protein were synthetized chemically. The sequences of amino acid residues for these peptides were ALEEAN, LKKDVDC, GLRRVLDE and RLKYENELA, respectively. The levels of interleukin (IL)-2, IL-4 and interferon (IFN)-γ were detected hy double-antihody sandwich ELISA assay. The proliferation of peripheral blood mononuclear cells (PBMCs) was detected by MTT method. The keratinocytes (HaCaT) were co-cultured with synthetic peptides. The proliferation of HaCaT was detected by MTT method. Results The expression levels of IL-2, IL-4 and IFN-7 were significantly higher in psoriatic PBMCs cultured with synthetic ALEEAN and LKKDVDC than those in normal PBMCs. These three cytokines were not detected in the cell culture supernatants of homologous peptides GLRRVLDE and RLKYENELA. The proliferation of HaCaT was promoted in synthetic peptides ALEEAN, LKKDVDC and GLRRVLDE co-treated with keratinocyte growth factor (KGF) (P < 0.05). Conclusion The keratin peptides homologous with M protein could promote proliferation of PBMCs and HaCat in patients with plague psoriasis, which may play a certain role in the pathogenesis of psoriatic aggravation and maintenance after hemolytic streptococcus infection.%目的 探讨与M蛋白同源的角蛋白肽段在银屑病发病中的作用.方法 人工合成与M蛋白同源的角蛋白肽段,氨基酸残基序列分别为ALEEAN、LKKDVDC、GLRRVLDE、RLKYENELA.4组合成同源肽段与银屑病患者和健康人(健康组)外周血单核细胞(PBMCs)共同培养.双抗体夹心ELISA法检测细胞因子白细胞介素(IL)-2、IL-4和γ干扰素(IFN-γ)的产生情况,MTT法检测PBMCs增殖情况.将合成同源肽段与角质形成细胞(HaCat)共培养,MTT法检测HaCat增殖情况,并对结果进行分析.结果 合成同源肽段ALEEAN和LKKDVDC均能刺激斑块型银屑病患者PBMCs增殖,IL-2、IL-4、IFN-γ分泌水平均显著高于健康组.在同源肽段GLRRVLDE、RLKYENELA中未检测到3种因子的表达.合成同源肽段ALEEAN、LKKDVDC、GLRRVLDE与角质形成细胞生长因子(KGF)共培养能促进HaCat增殖(均P＜0.05).结论 与M蛋白同源的某些角蛋白多肽可引起银屑病患者PBMCs和HaCat增殖,可能在银屑病,尤其是在β-溶血型链球菌感染后的银屑病皮损的维持与加重中起一定作用.