氢氧化铝佐剂对百日咳菌毛抗原的吸附特性分析

Adsorption property of aluminum hydroxide adjuvant to fimbriae antigen of Bordetella pertussis

目的探索氢氧化铝[Al(OH)_(3)]佐剂对百日咳菌毛(fimbriae,Fim)抗原的吸附特性及在组分百日咳疫苗制备中的应用。方法通过Zeta电位确定Fim抗原和Al(OH)_(3)佐剂的等电点(pI);朗格缪尔(Langmuir)吸附方程计算不同氯化钠(NaCl)浓度下,Fim抗原在Al(OH)_(3)佐剂表面的最大吸附量,根据最大吸附量随NaCl浓度的变化趋势判断吸附作用力种类,分析不同浓度磷酸盐和pH对Fim抗原吸附率的影响。采用间接ELISA法检测不同磷酸盐浓度下配制的Fim-Al(OH)_(3)复合物免疫小鼠后的血清抗体效价。结果 Fim抗原的pI为5.5,其最大吸附量随离子强度(NaCl)增加而基本保持不变,吸附率随磷酸盐浓度增加而缓慢降低,但仍保持在90%以上。先加磷酸盐后吸附的复合物免疫小鼠后血清抗体滴度高于其他组。结论 Fim抗原与Al(OH)_(3)佐剂的吸附作用除了静电吸引外,还存在配基交换方式,不同配制方式获得的Fim-佐剂复合物免疫小鼠产生的血清抗体滴度不同,为百日咳疫苗配制中加入Fim抗原提供了数据支持。

Objective To investigate the adsorption propertyof aluminum hydroxide adjuvant to fimbriae(Fim)antigen of Bordetella pertussis and application of adjuvant in the preparation of component pertussis vaccine. Methods The isoelectric points(pIs)of Fim antigen and aluminum hydroxide were determined by Zeta potential. The maximum amounts of Fim antigen adsorbed onto the surface of aluminum hydroxide adjuvant at various sodium chloride concentrations were calculated by Langmuir equation. The types of adsorption capacity were judged according to the changing trend of maximum adsorption capacity with sodium chloride concentration. The effects of concentration and pH value of phosphate on adsorption rate of Fim antigen were analyzed. The serum antibody titer of mice immunized with Fim-aluminum hydroxide complex prepared at different phosphate concentrations was determined by indirect ELISA. Results The pI of Fim antigen was 5. 5,while the maximum adsorption capacity of Fim remained constant with the increasing ionic strength(sodium chloride). The adsorption rate decreased slowly with the increasing phosphate concentration,which remained above 90%. The serum antibody titer of mice immunized with the complex prepared by adsorption after addition with phosphate was higher than those in other groups. Conclusion The study confirmed that the Fim antigen was mainly adsorbed onto aluminum hydroxide adjutant by ligand exchange in addition to electrostatic attraction,and the serum antibody titers of mice immunized with Fim-adjuvant complexes obtained by various formulations were different,which provided a data support for addition of Fim antigen into the formula of pertussis vaccine.