大肠杆菌O157∶H7多糖-重组铜绿假单胞菌外毒素A结合疫苗的研制

Preparation of conjugate vaccine composed of the O-specific polysaccharide of Escherichia coli O157∶H7 and rEPA

目的 用大肠杆菌O15 7∶H7(EscherichiacoliO15 7∶H7,E .coliO15 7)的一个重要保护性抗原即菌体脂多糖 (LPS)制备有效的候选疫苗。方法 选用Westphal热酚法提纯E .coliO15 7∶H7的LPS ,经酸水解法进一步脱毒处理后得到无毒但却具弱免疫原性的O 特异性多糖 (O SP) ,然后采用己二酸二肼 (ADH)将其共价结合到琥珀酰化 (或没琥珀酰化 )重组铜绿假单胞菌外毒素 (rEPAsucc或rE PA)上。结果 制备得到的E .coliO15 7∶H7的O SP rEPAsucc或O SP rEPA结合疫苗是安全有效的 ,其免疫原性要比单一O SP的免疫原性强 ,免疫小鼠后产生的血清抗LPSIgG抗体滴度比单一O SP免疫后产生的抗体水平均有显著性升高 (P <0 .0 1) ,且再次注射后存在加强应答。结论 E .coliO15 7∶H7的O SP rEPAsucc结合疫苗可望作为一种预防肠出血性E .

Objective The lipopolysaccharide(LPS)antigen of Escherichia coli O157∶H7 was used to develop a candidate conjugate vaccine against E. coli O157∶H7 infection. Methods The E. coli O157 LPS was extracted by the method of Westphal and detoxified by means of acid hydrosis, then the detoxified LPS (O-SP) was covalently bound to the succinylated(or native) rEPA (recombinant Pseudomonas aeruginosa exoprotein A). Results The resultant O-SP-rEPA conjugates showed to be safe and more immunogenic than the O-SP alone, and to elicit both statistically significant increases in anti-LPS IgG antibody titers in serum and booster responses when subcutaneously injected. Conclusion The O-SP-rEPA conjugate of E. coli O157 was an effective candidate vaccine against E. coli O157∶H7 infection. [