摘要
目的比较以白喉类毒素(diphtheria toxoid,DT)和重组铜绿假单胞菌外毒素A(recombinant Pseudomonas aeruginosa exotoxin A,r EPA)为载体蛋白,分别与伤寒Vi多糖(typhoid Vi polysaccharide,STVi)偶联的结合物的理化特性、抗原性及免疫效应。方法分别以DT、r EPA为载体蛋白,以己二酰肼(adipyl dihydrazide,ADH)为连接剂,使Vi多糖与载体蛋白共价偶联制备多糖蛋白结合物STVi-DT和STVi-r EPA,检测其理化特性指标、抗原性,再将其于0、14、28 d免疫NIH小鼠,经眼眶采血,分离血清,采用间接ELISA法检测小鼠血清抗体水平,分析其免疫原性、免疫记忆效应及免疫持久性。结果 STVi-DT、STVi-r EPA理化特性指标相似。STVi-DT针对STVi、DT抗血清均具有明显抗原性,而针对r EPA抗血清无抗原性,STVi-r EPA针对STVi、r EPA抗血清均具有明显抗原性,而针对DT抗血清无抗原性。Vi多糖和Vi多糖蛋白结合物均具有动物免疫原性,STVi蛋白结合物较STVi具有更强的免疫原性,STVi-DT的动物免疫原性试验结果略优于STVi-r EPA;免疫2剂STVi-DT和STVi-r EPA后,小鼠血清GMT明显升高,且STViDT组明显高于STVi-r EPA组(P<0.05),具有较强的免疫记忆效应;免疫STVi-DT和STVi-r EPA后,小鼠血清GMT随免疫剂次增加和时间延长持续升高,直至稳定在一定水平,免疫持久性较好。结论 STVi-DT、STVi-r EPA理化特性相似,均具有显著的免疫原性、免疫记忆效应及免疫持久性,而STVi-DT免疫原性、免疫记忆效应更强。
Objective To compare the physicochemical properties, antigenicities and immunological effects of typhoid Vi polysaccharide（STVi） conjugates prepared using diphtheria toxoid（DT） and recombinant Pseudomonas aeruginosa exotoxin A（r EPA）as carrier proteins respectively. Methods STVi was covalently conjugated to DT and r EPA using adipyl dihydrazide（ADH）as a linker respectively. The prepared conjugates STVi-DT and STVi-r EPA were determined for physical and chemical indexes and antigenicity. NIH mice were immunized with the conjugates on days 0, 14 and 28 respec-tively, and determined for antibody level in sera by indirect ELISA, based on which the immunogenicity, immune memory effect and immune persistence were analyzed. Results The physical and chemical indexes of STVi-DT and STVi-r EPA were in agreement. STVi-DT showed significant antigenicity to antisera against STVi and DT, while showed no antigenicity to that against r EPA. However, STVi-r EPA showed significant antigenicity to antisera against STVi and r EPA, while showed no antigenicity to that against DT. Both STVi and their conjugates showed immunogenicity in animals, while the immunogenicity of conjugates was superior to that of STVi, and that of STVi-DT was superior to that of STVi-r EPA. The GMTs of serum antibodies of mice increased significantly after immunization with two doses of STVi-DT or STVi-r EPA,which was significantly higher in STVi-DT group than in STVi-r EPA group（P 0. 05）, indicating strong immune memory.The GMTs of serum antibodies of mice immunized with STVi-DT and STVi-r EPA increased constantly then were maintained at high levels with the increasing doses as time went on, indicating a good immune persistence. Conclusion STViDT and STVi-r EPA showed similar physicochemical properties as well as significant immunogenicity, immune memory ef-fect and immune persistence, while STVi-DT was superior in immunogenicity and immune memory effect.
出处
《中国生物制品学杂志》
CAS
CSCD
2015年第5期456-460,共5页
Chinese Journal of Biologicals
基金
云南省科技计划项目(2014BC003)
关键词
伤寒Vi多糖
白喉类毒素
铜绿假单胞菌外毒素A
载体蛋白
Typhoid Vi polysaccharide Diphtheria toxoid（DT） Recombinant Pseudomonas aeruginosa exotoxin A（r EPA） Carrier protein
