CpG ODN佐剂序列IMB-AC5联合乙型肝炎疫苗的免疫原性分析

Immunogenicity of CpG ODN candidate adjuvant IMB-AC5 combined with hepatitis B vaccine

目的评价Cp G ODN佐剂序列IMB-AC5联合乙型肝炎疫苗的免疫原性,以评估IMB-AC5佐剂的应用前景。方法利用市售的单铝佐剂乙型肝炎疫苗,根据相同配比加入3种Cp G ODN（IMB-AC5及Coley 7909和Dynavax 1018）,作为实验组（V-AC5、V-7909和V-1018）,并以乙型肝炎疫苗为对照组,分别免疫BALB/c小鼠,于免疫后2、4、6、8周,经尾静脉采血,第10周处死小鼠采集全血,分离血清,采用乙肝表面抗体试剂盒检测anti-HBs抗体水平,ELISA法检测Ig G1/2a亚型抗体比例;ELISPOT法检测小鼠脾细胞IFNγ表达水平。结果免疫后0~4周内,各组小鼠血清抗体水平均无明显变化,第6周开始呈明显上升趋势,至第8周后趋于平缓;各实验组抗体水平均明显高于对照组（P〈0.05）,V-AC5显示出与V-7909同样良好的体液免疫效果,略优于V-1018。免疫后各实验组小鼠血清中Ig G2a/Ig G1比例明显高于对照组。各实验组小鼠脾细胞斑点数明显高于对照组（P〈0.05）;V-AC5斑点数介于其他两个实验组之间。结论 IMB-AC5佐剂能显著活化B细胞产生抗体并具有刺激细胞免疫的效果,可增强疫苗的免疫原性。

Objective To evaluate the immunogenicity of candidate Cp G ODN sequence IMB-AC5 as an adjuvant combined with hepatitis B（HB） vaccine.Methods Commercial HB vaccine containing aluminum adjuvant was added with three kinds of Cp G ODN（IMB-AC5,Coley 7902 and Dynavax 1018）and served as three test groups（V-AC5,V-7909 and V-1018）,respectively,using the HB vaccine as control.BALB/c mice were immunized with the vaccines in various groups respectively,and their venous blood samples were collected 2,4,6,and 8 weeks,and total blood at week 10 after immunization,from which sera were separated and determined for anit-HBs level by detection kit for HBs Ab,for Ig G1/Ig G2 a ratio by ELISA,and for expression level of IFNγ in splenocytes by ELISPOT.Results The serum antibody levels of mice in various groups showed no significant change 0 ~ 4 weeks,then showed a significantly increasing tendency from the 6th week,and was stable from the 8th week,after immunization.All the antibody levels in test groups were significantly higher than that in control group（P〈0.05）.The humoral immune effect in V-AC5 group was comparable to that in V-7909 group,while was slightly superior to that in V-1018 group.The Ig G2 a/Ig G1 ratios in sera and spot counts in splenocytes（P〈0.05）of mice in test groups were significantly higher than those in control group.However,the spot count in V-AC5 was between those in two test groups.Conclusion IMB-AC5 adjuvant significantly activated B cells to produce antibodies and stimulated cellular immunity,which enhanced the immunogenicity of vaccine.