B群脑膜炎奈瑟氏菌外膜蛋白抗原性分析

Analysis of the OMP antigenicity of serogroup B meningococci

挑选了１０株具有代表性的菌株，提取了它们的外膜蛋白（ＯＭＰｓ）。ＳＤＳ－ＰＡＧＥ分析发现：１０株菌的ＯＭＰｓ带谱不完全相同，但都含有１，２／３，４和５类外膜蛋白，而且纯化的１类外膜蛋白（ＯＭＰ１）显示一条分子量为（４１或４３）×１０３的蛋白带。从中选两株菌５４２８５２（Ｂ：ＮＴ：Ｐ１．２：Ｌ３，７，９：克隆Ｉ：ＲＦＬＰ－ｂ２０）和３４０７（Ｂ：１５：Ｐ１．２：Ｌ３，７，９：克隆群Ｉ：ＲＦＬＰ－ｂ２０）提纯了ＯＭＰ１，以每只小鼠５μｇ、１５μｇ和２５μｇ三个剂量组分别免疫，制备免疫血清。通过ＥＬＩＳＡ，杀菌力试验和双相琼扩试验分别测定了抗ＯＭＰ１特异性ＩｇＧ和杀菌抗体的滴度及ＩｇＧ的亚类组成。结果发现：以２５μｇ剂量组免疫小鼠所产生的ＩｇＧ抗体滴度最高；以菌株５４２８５２ＯＭＰ１所产生的ＩｇＧ抗体滴度较高；菌株５４２８５２的ＯＰＭ１诱导所产生的抗体含有ＩｇＧ１、ＩｇＧ２ａ和ＩｇＧ３亚类，对相同亚型菌株具有杀菌反应；用上述免疫血清与菌株５４２８５２和３４０７的ＯＭＰｓ及ＯＭＰ１进行Ｗｅｓｔｅｒｎｂｌｏｔｉｎｇ分析时，均出现一条分子量为（４１～４３）×１０３的反应带，这进一步证实了ＯＭＰ１与其免疫血清之间呈特异性?

Based on the phenotypes and genotypes of serogroup B meningococci isolated from patients and carriers in China since the 1970s,10 representative strains have been selected.Outer membrane proteins(OMPs)of the above 10 strains were extracted,their SDS PAGE profiles were found to be different,but each of them possessed the bands of class1,2/3,4 and 5 OMPs with MW 28kD 43kD.Class 1 outer membrane protein(OMP1) was further pruified from the 10 strains and each of them only showed one band with MW 41 or 43kD by SDS PAGE.Mice were immunized with 5μg,15μg and 25μg of the OMP1 purified from the two more representative strains 542852(B:NT:P1 2:L3,7,9:CloneⅠ:RFLP b20) and 3407(B:15:P1 2:L3,7,9:CloneⅠ:RFLP b20),respectively.The titers of antibody elicited by OMP1 were determined by ELISA and bactericidal test.The subclasses of IgG against OMP1 were also examined by immunodiffusion test.The results showed that the highest titers of IgG were induced by 25μg of OMP1 and the titer of IgG evoked by OMP1 of the strain 542852 was obviously higher than that of 3407.The specific antibody induced by OMP1 of the strain 542852 contained IgG1,IgG2a and IgG3,and had detectable bactericidal activity against serogroup B meningococci with same subtype.It was further indicated by Western blotting that the reactions of the above OMP1 with their antisera were specific.