灭活人55型腺病毒在小鼠体内免疫原性的评价

目的评价灭活人55型腺病毒(human adenovirus-55,HAdV-55)在小鼠体内免疫原性。方法将HAdV-55(SF04/SC/2016)毒株经0. 1%甲醛60℃热灭活12 h。将灭活HAdV-55与弗氏完全佐剂等体积混合,充分乳化,皮下注射BALB/c小鼠,200μL/只;2周后,将灭活HAdV-55与弗氏不完全佐剂等体积混合,充分乳化,加强免疫2次,间隔2周,同时设PBS对照组。每次免疫1周后经小鼠静脉采血,分离血清,ELISA法检测血清抗HAdV-55特异性抗体水平;通过免疫荧光法、ELISA法和体外中和试验检测末次免疫的血清抗体水平。结果灭活HAdV-55免疫小鼠产生了特异性抗HAdV-55抗体,随着免疫次数的增加,抗体滴度增大。灭活HAdV-55免疫小鼠血清可与HEp-2细胞内HAdV-55蛋白反应,产生荧光;总IgG水平均高于PBS对照组小鼠;可在HEp-2细胞上中和HAdV-55的感染,中和效价为1∶640~1∶1 280。结论灭活HAdV-55可作为免疫原诱导小鼠产生中和抗体,具有良好的免疫原性。

Immunogenicity of inactivated human type 55 adenovirus in mice

Objective To evaluate the immunogenicity of inactivated human adenovirus-55(HAdV-55)in mice. Methods HAdV-55 SF04/SC/2016 strain was inactivated with 0. 1% formaldehyde at 60 ℃ for 12 h,mixed with complete Freund adjuvant in a volume ratio of 1 : 1 and fully emulsified,with which BALB/c mice were immunized by subcutaneous injection,200 μL for each. Two weeks later,the inactivated HAdV-55 was mixed with incomplete Freund adjuvant in a volume ratio of 1 : 1 and fully emulsified,with which the mice were boosted for 2 times at an interval of2 weeks,using PBS as control. The sera of mice were collected one week after each immunization and determined for specific antibody level against HAdV-55 by ELISA. However,the serum antibody level after the last immunization was determined by IFA,ELISA and neutralization test in vitro. Results Specific antibody against HAdV-55 was induced in mice by inactivated HAdV-55,of which the titer increased with the increasing dose. The sera of mice immunized showed reaction with HAdV-55 protein in HEp-2 cells, with fluorescence produced. The total IgG level of mice immunized with HAdV-55 was higher than that in PBS control group. The sera of mice immunized with inactivated HAdV-55 neutralized the HAdV-55 infection on HEp-2 cells,with a neutralizing titer of 1 : 640 to 1 : 1 280. Conclusion Inactivated HAdV-55 strain may be used as an immunogen for induction of neutralizing antibody in mice,which showed good immunogenicity.