天然抗角蛋白自身抗体抗小鼠金黄色葡萄球菌感染的研究

目的 以高滴度天然抗角蛋白自身抗体(AK auto Ab)转基因小鼠为模型,分析AK auto Ab在抵御金黄色葡萄球菌感染中的作用.方法 取天然抗角蛋白自身抗体转基因小鼠及阴性对照小鼠,ELISA法检测小鼠腹腔冲洗液总IgM、抗角蛋白IgM抗体以及抗金黄色葡萄球菌IgM抗体水平:腹腔接种金黄色葡萄球菌制备感染模型,检测腹腔接种金黄色葡萄球菌后腹腔及肾脏菌落形成单位数量.测定菌负荷,流式细胞仪检测中性粒细胞比率、炎症因子浓度等.结果 ELISA检测发现,转基因小鼠腹腔冲洗液抗角蛋白IgM、抗金黄色葡萄球菌IgM水平高于阴性对照小鼠.差异有统计学意义(P<0.01);菌落形成实验显示,转基因小鼠腹腔及肾脏菌负荷低于阴性对照(P<0.01):流式细胞仪分析发现.转基因小鼠腹腔中性粒细胞比率、炎症因子浓度低于阴性对照(P<0.01).结论 AK auto Ab在小鼠体内对金黄色葡萄球菌感染具有良好的保护作用.

In vivo effects of natural anti-keratin autoantibody against Staphylococcus aureus infection in mouse model

Objective To investigate the role of natural anti-keratin autoantibody （AK auto Ab） in defense against Staphylococcus aureus （S. aureus） infection in vivo using AK auto Ab transgenic （Tg） mouse model. Methods Peritoneal cavity lavage fluid from Tg mice and littermate controls was analyzed by ELISA for the level of total IgM, anti-keratin IgM, and anti-S. aureus IgM. At 48 h after intraperitoneal （ip） inoculation with S. aureus , colony forming assay was used to detect the bacterial burden in abdominal cavity and kidney of these mice, and flow cytometry to assess the neutrophil percentage and inflammatory factor level in the peritoneal cavity lavage fluid of these mice. Results The IgM levels of anti-keratin and anti-S. aureus were significantly higher in Tg mice than those in the littermate controls （both P < 0.01）. Colony forming assay revealed that littermate controls displayed a significantly higher bacteria burden than Tg mice did （P < 0.01）. Both the neutrophil percentage and inflammatory factor concentration were significantly lower in Tg mice than those in the control （both P < 0.01） as indicated by flow cytometry. Conclusion These findings suggest that natural anti-keratin IgM may have an excellent protective effect against S. aureus in mice