呼吸道合胞病毒重组F蛋白疫苗的制备及免疫效果评价

Preparation and immunization effect evaluation of recombinant F protein vaccine of respiratory syncytial virus

目的制备呼吸道合胞病毒(respiratory syncytial virus,RSV)重组F蛋白疫苗,并对其免疫效果进行评价。方法制备两种基于RSV F蛋白的RSV疫苗:一种是以细菌样颗粒(bacterial like particle,BLP)为佐剂的黏膜疫苗,一种是以Al(OH)_(3)为佐剂的注射疫苗。将40只雌性BALB/c小鼠随机分为4组:BLP-F、BLP对照、AL-F和AL对照组,每组10只,BLP-F和BLP对照组经鼻内接种,AL-F和AL对照组经皮下接种。分别于第0、14、28天各免疫1次。末次免疫后2周,ELISA法检测小鼠血清IgG抗体效价及鼻洗液中IgA抗体效价,空斑试验检测中和抗体效价。结果两种疫苗均诱导了高水平的血清结合抗体和中和抗体,注射疫苗的诱导能力强于黏膜疫苗,注射疫苗可诱导血清中IgG升高,比黏膜免疫应答高约10倍,但不能诱导IgA升高,而黏膜疫苗可诱导高水平的黏膜IgA,但血清中IgG抗体相对较低。结论两种基于RSV F蛋白的疫苗均为有前途的候选疫苗,每种疫苗均有其自身的优势。后续研究将采用联合免疫的方式评估这两种疫苗作为免疫原的可行性,以同时增强针对RSV的全身和黏膜免疫应答。

Objective To prepare recombinant F protein vaccine of respiratory syncytial virus(RSV)and evaluate its immunization effect.Methods Two RSV vaccines based on RSV F protein were prepared:one was a mucosal vaccine with bacterial like particle(BLP)as adjuvant and the other was an injectable vaccine with aluminium hydroxide as adjuvant.Forty female BALB/c mice were randomly divided into four groups:BLP-F,BLP control,AL-F and AL control group,with 10mice in each group.BLP-F and BLP control group were inoculated intranasally,and AL-F and AL control group were inoculated subcutaneously.The mice were immunized once each at day 0,14 and 28,respectively.Two weeks after the last immunization,the titers of serum IgG antibody and IgA antibody in nasal lotion were detected by ELISA,and the titers of neutralizing antibody were detected by plaque test.Results Both vaccines induced high levels of serum binding antibodies and neutralizing antibodies,and the induction capacity of injected vaccine was stronger than that of mucosal vaccine.The injected vaccine induced the increase of IgG in serum,which was about 10 times higher than the mucosal immune response,but could not induce the increase of IgA.However,the mucosal vaccine induced the high level of mucosal IgA,but the serum IgG antibody was relatively low.Conclusion Both vaccines based on RSV F protein are promising candidates,and each vaccine has its own advantages.Follow-up studies will evaluate the feasibility of these two vaccines as immunogens using a combination immunization approach to simultaneously enhance systemic and mucosal immune responses against RSV.