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金黄色葡萄球菌是导致医院院内感染的主要病原。由于金黄色葡萄球菌极易产生抗药性,因此疫苗免疫是预防该细菌感染的主要手段。作为一个粘附分子,凝集因子B(ClfB)的作用是使金黄色葡萄球菌能够在宿主黏膜定植,是预防该菌感染的一个重要的靶分子。本研究成功地在大肠杆菌中表达了可溶的ClfB N1-N3结构域蛋白(Truncated-ClfB),并且利用亲和层析、离子交换层析和凝胶过滤技术对其进行了纯化。用纯化后的Truncated-ClfB免疫新西兰大白兔,收集三免后的血清检测其抗体水平并且利用流式细胞术检测抗血清的调理吞噬活性。检测结果表明,三免后的兔源Truncated-ClfB抗血清抗体效价高达1:640 000;与免疫前兔源血清相比,兔源Truncated-ClfB抗血清能够显著增加多形核白细胞(Polymorphonuclear leukocytes,PMN)对金黄色葡萄球菌的吞噬效率(P<0.01)。结果表明Truncated-Clf B有希望作为金黄色葡萄球菌疫苗的候选抗原。
Staphylococcus aureus is the main cause of nosocomial infections in hospitals. Because Staphylococcus aureus is extremely resistant, vaccine immunization is the primary means of preventing the bacterial infection. As an adhesion molecule, agglutination factor B (ClfB) plays an important role in preventing Staphylococcus aureus colonization in host mucosa. This study successfully expressed soluble ClfB N1-N3 domain protein (Truncated-ClfB) in Escherichia coli and purified it by affinity chromatography, ion exchange chromatography and gel filtration. New Zealand white rabbits were immunized with the purified Truncated-ClfB, the serums of the three immunizations were collected to detect the antibody levels, and the opsonic phagocytosis activity of the antisera was detected by flow cytometry. The results showed that the titer of rabbit anti-Truncated-ClfB antiserum was up to 1: 640 000 after three -free immunization. Compared with pre-immune rabbit serum, the antiserum against Truncated-ClfB could significantly increase the number of polymorphonuclear leukocytes , PMN) on Staphylococcus aureus phagocytosis efficiency (P <0.01). The results indicate that Truncated-Clf B is promising as a candidate antigen for S. aureus vaccines.