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B群链球菌(GBS)是造成新生儿及婴幼儿感染的常见病原体,病死率达5%～8%. 母体抗GBS荚膜多糖(CPS)抗体可透过胎盘对胎儿产生保护作用.但是纯化的GBSCPS在成人中的免疫原性不稳定,因此作者研制了一种Ⅲ型GBS CPS-蛋白(破伤风类毒素)结合(Ⅲ-TT)菌苗,以期增强其在成人中的免疫原性.100名妇女随机接受了不同剂量的Ⅲ-TT菌苗、Ⅲ型GBS CPS或生理盐水.分别于免疫前和免疫后2、4、8及26周采血,检测抗Ⅲ型CPS特异性抗体.结果表明Ⅲ是-TT菌苗可为人体耐受,免疫8周后,最高剂量Ⅲ-TT菌苗组受试者的CPS特异性IgG水平从免疫前的0.09μg/ml升至4.53μg/ml,而Ⅲ型CPS组受试者仅从0.21μg/ml升至1.41μg/ml.Ⅲ-TT菌苗组中90%的受试者血清抗体浓度升高4倍以上,而Ⅲ型CPS组中仅50%的受试者抗体浓度升高4倍.由皿-TT菌苗诱生的抗体能识别Ⅲ型CPS的构象依赖性表位,促进调理吞噬作用并杀灭GBS.母鼠免疫后,能保护新生小鼠抵御Ⅲ型GBS的致死性攻击.
Group B Streptococcus (GBS) is a common causative agent of neonatal and infant infections with a mortality rate of 5% -8% .The maternal anti-GBS capsular polysaccharide (CPS) antibody can protect the fetus through the placenta.But the purification Of the GBSCs are not immunogenic in adults, the authors developed a type III GBS CPS-protein (tetanus toxoid) binding (III-TT) vaccine to enhance their immunogenicity in adults. 100 women were randomized to receive different doses of either type III-TT vaccine or type III GBS CPS or saline, and blood samples were collected before immunization and at 2, 4, 8 and 26 weeks after immunization to detect anti-class III CPS-specific antibodies. The results showed that the Ⅲ -TT vaccine could be tolerated by human. After 8 weeks of immunization, the CPS-specific IgG level of the highest dose Ⅲ-TT vaccine group increased from 0.09μg / ml before immunization to 4.53μg / ml, While the type CPS group only increased from 0.21μg / ml to 1.41μg / ml.The serum antibody concentration in 90% of the patients in theⅢ-TT vaccine group was more than 4 times higher than that in the type Ⅲ CPS group 50% of the subjects increased the antibody concentration by a factor of 4. The antibodies elicited by the pan-TT vaccine recognize the conformation-dependent epitope of type III CPS and promote phagocytosis and kill GBS. After the outbreak, can protect neonatal mice against lethal type III GBS attacks.