A群脑膜炎球菌多糖结合物的免疫原性研究

目的：制备A群脑膜炎球菌多糖（PS）结合物，观察其免疫原性。方法：A群脑膜炎球菌多糖经溴化氰活化后共价接上己二酰肼手臂，在碳二亚胺催化下与精制破伤风类毒素（TT）偶联剂备结合物。单独多糖、多糖结合物和TT按相同程序免疫NIH小鼠，用ELISA法检测小鼠血清抗多糖抗体滴度和特异性及抗TT抗体滴度。结果：用上述实验方法制备的结合物具有多糖和蛋白质的抗原性，免疫小鼠可诱导高滴度的血清抗多糖IgG抗体，免疫2针后高滴度抗体至少持续存在3周。血清抗体可中和多糖。加强免疫提示有免疫记忆性。结合物还可诱导产生一定水平的TT抗体。结论：A群脑膜炎球菌多糖结合到TT上可明显增强多糖在小鼠中的免疫原性，为制备结合疫苗并研究其对婴幼儿的免疫原性提供了实验基础。

Immunogenicity of group A meningococcal polysaccharide conjugate

Objective To synthesize group A meningococcal polysaccharide(PS) protein conjugate and study on its immunogenicity. Methods Conjugate was prepared by carbodiimide mediated coupling of adipic acid hydrazide derivatives of capsular polysaccharides of group A meningococcal with tetanus toxoid(TT). NIH mice were immunized with conjugate, plain PS and TT, and the anti PS and anti TT antibodies were tested by ELISA. Results The conjugate vaccine showed the antigenicities of PS and TT. High titers of anti PS antibody elicited in immunized mice, and could last for at least 3 weeks after the second injection. The anti PS antibody in immunized mice sera could be neutralized by polysaccharide. Immunological memory was detected as well. The anti TT antibodies could be also induced. Conclusion The immunogenicity of group A meningococcal polysaccharide in conjugate has been greatly improved in mice, which has laid a foundation for preparation of conjugate vaccine and for evaluation of its immunogenicity in infants. [