氢氧化铝佐剂对肠道病毒71型灭活疫苗诱导小鼠细胞免疫应答的影响

目的评价氢氧化铝佐剂对肠道病毒71型(Enterovirus 71,EV71)灭活疫苗诱导小鼠细胞免疫应答的影响。方法用含铝佐剂及无佐剂EV71灭活疫苗免疫BALB/c小鼠,并设生理盐水对照组。于加强免疫后7 d采血,进行小鼠脾单个核细胞(Mononuclear cell,MNC)的分离及CD8+T细胞的去除,采用酶联免疫斑点法(ELISPOT)检测经EV71疫苗原液或VP2-36刺激后的小鼠脾MNC分泌IFNγ水平;应用液相芯片技术(LUMINEX)检测经EV71疫苗原液刺激后的小鼠脾MNC分泌IL-2、IL-4、IL-5、IL-6和IL-10水平;采用体外微量中和试验法检测小鼠血清中和抗体效价。结果 BALB/c小鼠经2次免疫后,铝佐剂疫苗组小鼠脾MNC的IFNγSFC值显著高于无佐剂疫苗组(P均<0.05);铝佐剂疫苗组分泌IL-6和IL-10水平显著高于无佐剂疫苗组(P均<0.05);铝佐剂与无佐剂疫苗组小鼠血清EV71中和抗体阳转率均达到100%,铝佐剂疫苗组诱导的中和抗体效价显著高于无佐剂疫苗组(P<0.01)。结论 EV71灭活疫苗可诱导BALB/c小鼠产生特异性IFNγ、IL-2、IL-6和IL-10应答,铝佐剂可同时增强EV71灭活疫苗的Th1和Th2类免疫应答。

Effect of aluminum hydroxide adjuvant on cellular immune response induced with inactivated enterovirus 71 vaccine in mice

Objective To evaluate the effect of aluminum hydroxide adjuvant on cellular immune response induced with inactivated enterovirus 71(EV71)in mice.Methods BALB / c mice were immunized with aluminum hydroxide adjuvant-containing and adjuvant-free inactivated EV71 vaccines respectively,using physiological saline as control.Blood samples were collected 7 d after booster immunization,from which mononuclear cells(MNCs) were isolated and CD8+ T cells were removed.The secretion level of IFNγ by mouse splenic MNCs after stimulation with bulk EV71 vaccine or VPI-36 was determined by ELISPOT,while those of IL-2,IL-4,IL-5,IL-6 and IL-10 by LUMINEX technique.The serum neutralizing antibody titers of mice were determined by micro-neutralization test in vitro.Results The number of spot-forming cells(SFCs)of IFNγ secreted by MNCs of BALB / c mice immunized twice with aluminum hydroxide adjuvant-containing EV71 vaccine were significantly higher than those with adjuvant-free vaccine(P < 0.05).Both the positive conversion rates of neutralizing antibody against EV71 in sera of mice immunized with aluminum hydroxide adjuvantcontaining and adjuvant-free vaccines were 100%.However,the neutralizing antibody titer induced by aluminum hydroxide adjuvantcontaining was significantly higher than that by adjuvant-free vaccine(P < 0.01).Conclusion Inactivated EV71 vaccine induced secretion of specific IFNγ,IL-2,IL-6 and IL-10,and aluminum hydroxide adjuvant enhanced Th1 and Th2 immune responses induced by inactivated EV71 vaccine.