C群脑膜炎球菌结合疫苗的制备及其免疫原性

摘要

目的 制备由不同分子大小C群脑膜炎球菌多糖(group C meningococcal polysaccharide,CPS)与破伤风类毒素(tetanus toxoid,TT)共价偶联而成的结合疫苗(CPS-TT),并检测其在小鼠中的免疫原性.方法 将CPS降解成不同大小的片段,经碳二亚胺(carbodiimide,EDAC)或溴化氰(cyanogen bromide,CNBr)活化后偶联到TT上制成CPS-TT.NIH小鼠皮下注射制备的不同CPS-TT,用ELISA法测定小鼠血清抗CPS和TT IgG抗体.结果 EDAC活化的降解CPS的衍化率(3.9％～5.7％)和多糖回收率(11.4％～21.3％)均高于CNBr活化的降解CPS的衍化率(0.4％～1.2％)和回收率(2.4％～11.5％).EDAC或CNBr活化的降解CPS制备的CPS-TT在小鼠中均具有较强的免疫原性,但EDAC活化的降解CPS制备的CPS-TT免疫小鼠的抗CPS抗体滴度高于CNBr活化的降解CPS制备的CPS-TT免疫小鼠.结论 EDAC活化的降解CPS可用于制备C群脑膜炎球菌结合疫苗.%Objective To prepare conjugate vaccines by covalently coupling group C meningococcal polysaccharides (CPS) of different molecular sizes and tetanus toxioid (TT),and to determine their immunogenicity in mice.Methods CPS was degraded into different size fragments and conjugated to TT after activated by carbodiimide (EDAC) or cyanogen bromide (CNBr) to prepare conjugate vaccines (CPS-TT).NIH mice were immunized with these conjugate vaccines and both serum anti-CPS and antiTT IgG were determined by ELISA.Results Derivation rates and yields of degraded CPS activated by EDAC were higher than those of degraded CPS activated by CNBr,with 3.9％-5.7％ vs.0.4％-1.2％ and 11.4％-21.3％oo vs.2.4％-11.5％,respectively.CPS-TT prepared with degraded CPS activated by either EDCA or CNBr were all highly immunogenic in mice,but anti-CPS antibody levels in mice immunized with CPS-TT prepared with degraded CPS activated by EDCA were higher than those in mice immunized with CPS-TT prepared with degraded CPS activated by CNBr.Conclusion Degraded CPS activated by EDAC can be used to prepare group C meningococcal polysaccharide conjugate vaccine.