CpG-ODN和氢氧化铝复合佐剂对流感病毒裂解疫苗免疫效果的影响

目的 研究CpG-ODN和氢氧化铝复合佐剂对流感病毒裂解疫苗体液免疫和细胞免疫效果的影响,为今后研制新佐剂流感疫苗和解决流感疫苗产能不足的问题提供依据.方法 以不同剂量的2009 H1N1流感病毒裂解疫苗为抗原,分别以CpG-ODN、氢氧化铝以及CpG-ODN和氢氧化铝复合佐剂为疫苗佐剂免疫BALB/c小鼠,通过ELISA、血凝抑制试验和假病毒中和试验等方法评价体液免疫效果,通过ELISPOT、胞内细胞因子染色和体内CTL杀伤等方法评价细胞免疫效果.结果 与无佐剂对照组相比,CpG-ODN或氢氧化铝单独使用能够在一定程度上增强体液免疫,2针免疫后不同抗原剂量组中抗原特异性IgG抗体滴度、血凝抑制抗体滴度和中和抗体滴度分别提高3～6倍、2～4倍和4～8倍.CpG-ODN和氢氧化铝复合佐剂具有更强的佐剂效应,2针免疫后不同抗原剂量组中抗原特异性IgG抗体滴度、血凝抑制抗体滴度和中和抗体滴度分别提高23～ 57倍、9～20倍和16～64倍.根据体液免疫结果,复合佐剂能够使流感病毒裂解疫苗的抗原用量降低至少16倍.此外,复合佐剂能够显著增强流感病毒裂解疫苗的细胞免疫应答,不但能够促进抗原特异性CD4+T细胞的IFN-γ分泌,而且能够促进抗原特异性CD8+T细胞的CTL杀伤活性.结论 CpG-ODN和氢氧化铝复合佐剂能够增强流感病毒裂解疫苗的体液免疫和细胞免疫应答并显著降低抗原用量.

CpG-ODN plus alum as a composite adiuvant to enhance the immunogenicity of influenza split virion vaccine

Objective To evaluate the immuno-potentiating effects of CpG-ODN plus alum as a composite adjuvant on influenza split virion vaccine.Methods BALB/c mice were immunized with various amounts of 2009 H1N1 influenza split virion vaccine,alone or in combination with CpG-ODN,alum,or both (composite adjuvant).Antigen-specific humoral immune responses were evaluated by ELISA,hemagglutination inhibiting (HI) assay and neutralizing assay.Antigen-specific cellular immune responses were evaluated by ELISPOT assay,intracellular cytokine staining assay and in vivo CTL assay.Results Compared with the control group immunized with antigen alone,a single use of either adjuvant weakly enhanced the humoral immune responses,as indicated by the increase of antigen-specific IgG titers,HI titers and neutralizing titers by 3-6 folds,2-4 folds and 4-8 folds,respectively,after two immunizations.In contrast,the composite adjuvant induced more potent humoral immune responses; the antigen-specific IgG titers,HI titers and neutralizing titers were increased by 23-57 folds,9-20 folds and 16-64 folds,respectively.Consequently,the composite adjuvant achieved antigen-sparing by at least 16 folds.In addition,the composite adjuvant significantly enhanced the antigen-specific cellular immune responses,as revealed by the increase of IFN-γ-secreting CD4+ T cells and the enhancement of CTL activity in immunized mice.Conclusion CpG-ODN plus alum as a composite adjuvant can enhance the immunogenicity of influenza split virion vaccine and achieve the antigen-sparing effect.