应用免疫金标记技术分析福氏2a痢疾杆菌膜抗原

Localization of the Membrane Antigens on the Cell Wall of Shigella Flexneri 2a with Immunogold labeling

本文报告应用抗福氏２ａ痢疾杆菌膜成份ＭｃＡｂ及胶体金探针对细菌膜抗原进行了定位。结果显示４种抗脂多糖ＭｃＡｂ（３Ａ６、２Ｅ６、４Ｆ１．２Ａ３）可不均一的识别位于细菌表面的抗原，而另外一种抗ＬＰＳＭＣＡｂ（１Ｇ８）和一抗膜蛋白ＭｃＡｂ（１Ａ１）识别的抗原未暴露于细菌表面。应用细菌膜碎片包埋前染色成功地定位了抗胰蛋白ＭｃＡｂ１Ａ１位于细菌内膜的抗原。与ＭｃＡｂ的生物学活性比较表明。阳性标记细菌表面抗原的ＭｃＡｂ的抗原与其阻断志贺氏菌接触性溶血试验和对小鼠的被动保护力密切相关。提示免疫电镜标记技术确定抗原表位在细菌表面的可及性和拷贝数对构建和筛选痢疾工程菌苗具有重要意义。

The localizations of Shigella flexneri 2a membrane antigens were determined by electron mieroscpy by using six McAbs against Shigella flexneri 2a membrane components and immunogold labbing.Binding of the McAbs on whole bacterial cells indicated that the antigens recognized by McAbs 3A6,2E6,4F1 and 2A3 were exposed on the cell surface,and those by McAbs 1A1 and 1G8 were not. Labeling for McAb 1A1was successfully performed by using sonicated bacterial sediment and pre-embeded immunogold staining. Gold particles on the inner membrane of the bacteria were observed.Comparing with the biological activities of these McAbs,the results showed that exposure of the antigenic determinents on the bacteria surface had a direct bearing on their bloking activities of the contact haemolysis and the passive protecting capacities in mice.All these suggested that understanding of the accessibility and numbers of copies to the bacterial protecting antigenic determinents had a great significance in the construction and s election of Shigella vaccine.