不同佐剂的复合黏膜疫苗鼻内免疫小鼠抗弓形虫感染的保护作用

目的比较IFN-γ和蜂胶作为佐剂鼻内免疫小鼠抗弓形虫攻击的能力，探索两种佐剂联合应用的效果。方法将5-6周龄雌性BALB／c小鼠60只随机分为4个组，每组15只，分别用20雌可溶性速殖子抗原（STAg）、20μg STAg＋40μg蜂胶、20μgSTAg＋1000U IFN-γ或20μgSTAg＋40μg蜂胶＋1000UIFN-γ鼻内免疫小鼠2次．间隔14d。末次免疫后第10天，用RH株弓形虫速殖子4×10^4个／只灌胃攻击，逐日观察小鼠存活情况。攻击后第43天处死全部存活小鼠，计算胸腺、脾指数，计数脑、肝组织速殖子。结果STAg＋IFN-γ组、STAg＋蜂胶＋IFN-γ组胸腺、脾指数显著高于STAg组（P〈0．05）；组织内速殖子虫荷显著降低（P〈0．01），STAg＋IFN-γ组小鼠脑、肝组织减虫率分别为57．00％和79．06％；STAg＋蜂胶＋IFN-γ组小鼠脑、肝减虫率分别为68．30％和79．06％。STAg＋蜂胶组小鼠胸腺、脾指数有升高趋势，组织内速殖子虫荷降低，但与STAg组比较差异无统计学意义。结论在抗弓形虫感染中，IFN-γ、蜂胶＋IFN-γ的佐剂效果优于蜂胶，IFN-γ、蜂胶＋IFN-γ辅助STAg显著提高小鼠胸腺、脾比重，增强机体免疫能力，有效抵抗弓形虫的感染攻击，脑、肝组织速殖子虫荷显著减少。

Protective Effect Induced by Intranasal Immunization with Toxoplasma gondii Mucosal Vaccine Plus Different Adjuvants in Mice

Objective To compare the effect of IFN-γ, propolis and the combination of IFN-γ and propolis as adjuvant of STAg for intranasal immunization against Toxoplasma gondii. Methods Sixty 5- to 6-week-old female BALB/c mice were randomly divided into four groups. Fifteen mice of each group were immunized intranasal two times at 14-day intervals with 20 μg STAg alone, 20 μg STAg plus 40 μg propolis, 20 μg STAg plus 1 000 U IFN- γ or 20 μg soluble tachyzoite antigen （STAg） plus 40 μg propolis＋ 1000 U IFN-γ. The PBS containing 4×10^4 tachyzoites of RH strain in each 0.5 ml volume were orally administered to all animals on day 10 after the last immunization. The survival of mice was recorded day by day. Survivors were killed on day 43 after infection, the thymus index and spleen index were calculated, and the tachyzoites of brains and livers were counted. Results The thymus index and spleen index in the groups of STAg plus IFN-γ and STAg plus propolis ＋IFN-γ were obviously higher than that of the STAg group （P〈0.05）, the taehyzoites were significantly decreased than that of STAg group （P〈0.01）, the reduction rate in brains and livers of STAg plus IFN-γ group were 57.00%, 79.06%, respectively, and 68.30%, 79.06% of STAg plus propolis＋IFN-γ group. The thymus index and spleen index were increased and the tachyzoites were decreased in the groups of STAg plus propolis, but no significant differentiation. Conclusion IFN-γ , and propolis＋IFN-γ are effective adjuvant for STAg intranasal immunization against Toxoplamsa gondii. STAg plus IFN-γ or STAg plus propolis＋IFN-γ can effectively improve the thymus index and spleen index and protect mice against Toxoplasma gondii infection, and the tachyzoites were significantly decreased.