rCTB和TT为蛋白载体的A群流脑多糖黏膜免疫初步研究

目的 对重组霍乱毒素B亚单位(rCTB)作为多糖蛋白结合疫苗候选载体的可行性进行分析,并对以破伤风类毒素(TT)与rCTB为蛋白载体的黏膜投递型疫茸的免疫效果进行初步探讨.方法 首先通过基因工程手段获得具有五聚体结构的rCTB.再将rCTB五聚体蛋白利用化学方法(ADH方法)与A群脑膜炎球菌多糖(GAMP)耦联,获得多糖蛋白结合物GAMP-rCTB,并将其与TT为蛋白载体的A群流脑多糖蛋白结合物(GAMP-TT)以滴鼻和注射途径免疫BALB/c小鼠,并对其进行免疫学评价.结果 以rCTB和TT为载体的A群流脑多糖蛋白结合物,通过黏膜投递途径均可在血清中产生相对较高的多糖特异性IgG抗体,在肺部盥洗液和小肠黏膜也产生了相应的特异性IgA抗体.结论 rCTB和TT均可作为黏膜投递型多糖结合疫苗的候选蛋白载体.以rCTB为载体的多糖蛋白结合物,黏膜途径可能在免疫功能方面优于注射途径.

The effect of meningococcal serogroup A polysaccharide-protein conjugate vaccine prepared with TT and rCTB on mucosal immune responses

Objective To analyze the feasibility of the recombinant cholera toxin B subunit (rCTB) as a carrier protein candidate for the preparing of polysaccharide-protein conjugate, and to discuss the immune effects of tetanus toxoid (TT) as the carrier protein in mucosal delivery vaccine. Methods The refolded pentrumer protein, rCTB was obtained by genetic engineering methods. Then conjugated the refold-ed protein with group A meningococcal polysaccharide (GAMP) using the chemical method(ADH) ,the pol-ysaccharide-protein conjugates(GAMP-rCTB) were prepared. BALB/c mice were immunized either intraper-itoneally ( i. p. ) or intranasally ( i. n. ) with GAMP-rCTB. Moreover, GAMP-TT vaccine that TT as carrier proteins was i.n. immunized to the mice. The evaluation of immunology is performed. Results The conju-gates of polysaccharide-potein with the rCTB and TT as protein carrier both are able to elicit high level of GAMP specific IgG antibody in serum after i.n. immunization, and the conjugates can also elicit specific IgA antibody in lung lavage and intestinal mucosa. Conclusion rCTB and TT can both as the protein carri-er for polysaccharide-protein conjugate as mucosal vaccine. The route of intranasal may be more ways for im-mune function than i.p. immunization when rCTB is used as the carrier of the polysaccharide-protein conju-gates.