弓形虫STAg联合IFN-γ佐剂滴鼻免疫小鼠诱导不同黏膜部位抗体水平动态观察

目的观察弓形虫可溶性速殖子抗原（soluble tachyzoite antigen,STAg）联合IFN-γ佐剂滴鼻免疫BALB/c小鼠后不同黏膜部位抗体水平及其持续时间,为黏膜疫苗研制提供实验依据。方法 84只5~6周龄BALB/c小鼠随机分为免疫组和对照组,每组42只。免疫组以STAg（20μg/只）为抗原加IFN-γ（1 000 U/只）为佐剂滴鼻免疫,对照组以PBS 20μl滴鼻。共滴鼻2次,间隔2周。首次免疫后第0、2、4、6、8、10、12周每组处死6只小鼠,ELISA法测定鼻咽、肺和小肠冲洗液sIgA、IgG水平。结果小鼠用弓形虫STAg联合IFN-γ首次免疫后鼻咽冲洗液sIgA和IgG水平均增高,其中第2、4、6、8周sIgA水平显著高于对照组（P〈0.05）,第2、4、6周IgG水平高于对照组（P〈0.05）;首次免疫后第6、8周小鼠肺冲洗液sIgA水平显著高于对照组（P〈0.05）,第4、6、8周IgG水平高于对照组（P〈0.05）;首次免疫后第2、4、6周小肠冲洗液sIgA水平高于对照组（P〈0.05）,第2、4、6、8周IgG水平高于对照组（P〈0.05）。免疫后不同黏膜部位抗体均以sIgA为主,且以肠道冲洗液最高。结论 STAg联合IFN-γ佐剂滴鼻免疫BALB/c小鼠可诱导鼻咽、肺和小肠黏膜部位产生高水平sIgA和IgG抗体应答,并可持续6~8周。表明滴鼻免疫是弓形虫疫苗的适宜接种途径。

Observation of the kinetics of antibodies in different portions of mucosa in mice immunized intranasally with Toxoplasma gondii STAg and IFN-gamma adjuvant

Objective This study was performed to investigate the kinetics of sIgA and IgG antibodies in the nasopharynx,lungs,and intestines of mice intranasally immunized withToxoplasma gondiisoluble tachyzoite antigen（STAg） and IFN-gamma adjuvant.Methods Eighty-four 5-to 6-week-old BALB/c mice were randomly divided into an immunized group and a control group,with 42 mice per group.Immunized mice were intranasally immunized with 20 μg STAg and 1 000 U IFN-γ in 20 μl PBS per mouse twice at an internal of 2 weeks,while the control mice were given 20 μl PBS instead.Six mice from each group were sacrificed at weeks 0,2,4,6,8,10,and 12 after the first immunization.The levels of sIgA and IgG in the nasopharynx,lung,and intestinal washes were determined by ELISA.Results Intranasal immunization with STAg and IFN-gamma adjuvant effectively induced an antibody immune response in different portions of mucosa,and the response continued for a relatively long period of time.The levels of sIgA and IgG in nasopharynx washes from the immunized group gradually increased after immunization.In weeks 2,4,6,and 8,sIgA was significantly higher（P0.05） than the level in the control group after the first immunization;in weeks 2,4,and 6,IgG was also was significantly higher.The level of sIgA in weeks 6 and 8 and the level of IgG in weeks 4,6,and 8 in lung washes of the immunized group were significantly higher（P0.05） after the first immunization than respective levels in the control group.The level of sIgA in intestinal washes from the immunized group gradually increased after immunization and differed significantly（P0.05） from that in the control group in weeks 2,4,and 6;the level of IgG was significantly higher（P0.05） than that in the control group in weeks 2,4,6,and 8.Antibodies in the nasopharynx,lungs,and intestines were mostly sIgA,and intestinal washes had the highest number of antibodies.Conclusion Intranasal immunization with STAg and TFN-gamma adjuvant induced greater sIgA and IgG immunological responses that continued for 6-8 weeks.Intranasal immunization is a suitable vaccination route for theT.gondiivaccine.