B族链球菌表面免疫原性蛋白的黏膜免疫效果

Mucosal Immune Effect of Group B Streptococcal Surface Immunogenic Protein

目的探讨B族链球菌(GBS)表面免疫原性蛋白(Sip)的黏膜免疫效果。方法表达及纯化两种不同标签的Sip(Gp-Sip和pET-Sip),质谱分析法鉴定纯化蛋白。用Gp-Sip免疫BALB/c小鼠,pET-Sip检测免疫小鼠血清及阴道黏膜萃取液中特异性抗体水平,调理吞噬试验检测Sip抗血清的调理吞噬活性。结果经质谱分析和蛋白质库比较证实,纯化的Gp-Sip和pET-Sip为B族链球菌Sip的可能性分值分别为177和92。ELISA检测结果显示,Sip+CT经鼻内及直肠两种途径黏膜免疫后,均可诱发小鼠产生高水平的血清IgG及阴道黏膜IgA抗体,鼻内免疫效果优于直肠;不同剂量的Sip+CT鼻内免疫后,均可在血清及阴道黏膜中检出高水平的IgG和IgA抗体,组间比较差异无统计学意义;CT和CpG-ODN1826鼻内免疫均可促进Sip产生较好的黏膜免疫效果,二者之间差异无统计学意义。Sip抗血清可明显地促进吞噬细胞对GBS的吞噬作用。结论Sip具有较好的黏膜免疫原性,鼻内黏膜免疫效果优于直肠,CT和CpG-ODN1826两种佐剂均可有效提高Sip的免疫原性。

Objective To investigate the mucosal immune effect of group B streptococcal surface immunogenic protein （Sip）. Methods Gp-Sip and pET-Sip were expressed and purified respectively, then analyzed by mass spectrometry. BALB/c mice were immunized with Gp-Sip, and the specific antibody levels in sera and vaginal mucosa extract were determined with pET-Sip. The opsonophagocytic activity of Sip antisera was determined by opsonophagocytosis test. Results Mass spectrometry proved that the probability-based mowse scores for Gp-Sip and pET-Sip as group B Sip were 177 and 92 respectively. ELISA showed that both immunization with Sip by intranasal and rectal routes induced high IgG titer in sera and high IgA titer in vaginal mucosa. However, the antibody levels induced by intranasal immunization were significantly higher than those by rectal immunization. No significant differences were observed in IgG and IgA levels induced by Sip ＋ CT at various dosages. Both CT and CpG-ODN1826 as adjuvant enhanced the mucosal immune effect of Sip by intranasal route, which showed no significant difference. Sip antisera increased the phagocytic activity of phagocytes to GBS. Conclusion Sip showed good mucosal immunogenicity, and the immune effect by intranasal route was superior to that by rectal route. Both CT and CpG-ODN1826 as adjuvant enhanced the immunogenicity of Sip effectively.