摘要
目的初步评价mip基因DNA疫苗的免疫保护性.方法将20只6～8周龄、体重25 g左右的BALB/c雌性小鼠,随机分为空白对照组、pcDNA3.1(+)阴性对照组、pcDNA3.1-mip免疫组、pcDNA3.1-mip/ctxB免疫组4个组.每只小鼠股四头肌肌肉注射进行免疫接种,初次免疫2周后加强免疫1次,加强免疫2周后,小鼠腹腔注射嗜肺军团菌L1菌液进行攻击.攻击28 d后,检测小鼠肺组织培养带菌量和肺组织病理形态学变化.结果 pcDNA3.1-mip免疫组和pcDNA3.1-mip/ctxB免疫组肺组织培养带菌量少于空白对照组和阴性对照组(ANOVA,P＜0.05).小鼠肺组织肉眼未见明显病理变化,在显微镜下观察肺组织病理切片,发现空白对照组与阴性对照组主要表现为渗出性病变,可见肺泡膈明显增宽,肺毛细血管扩张充血,明显的中性粒细胞浸润,肺泡腔内有渗出物;而应用DNA疫苗的两个免疫组无渗出性病变,pcDNA3.1-mip免疫组肺泡壁和肺间膈轻度增厚,pcDNA3.1-mip/ctxB免疫组肺泡壁和肺泡膈略微增厚.结论应用mip基因DNA疫苗能诱导小鼠在体内产生一定的免疫保护效应.
The immune protection of the mip/ctxB fusion gene in Legionella pneumophila was investigated by the mouse immunization assay, in which 20 female BALB/c mice of 6-8 weeks old were grouped randomly into four groups, the physiological saline group; pcDNA 3.1（ ＋ ） immunized group; pcDNA 3.1-mip immunized group and pcDNA 3.1-mip/ctxB immunized group. Mice were immunized intramuscularly either with physiological saline severed as blank control or with different plasmid DNA as vaccines for immunization. Immunization was boosted twice with the same dosages at two weeks interval. After the last immunization, all of the mice were challenged with Legionella pneumophila serotype 1 and 28 days after challenging, the bacterial counts and the pathological changes in lungs were determined and observed to evaluate the protective immunity. The results showed that the bacterial counts in the pcDNA 3.1-mip immunized group and pcDNA 3.1-mip/ctxB-immunmized group were significantly lower than those of the physiological saline group and the pcDNA 3.1 （ ＋ ） immunized group. （ANOVA, P 〈 0.05 ）, and the exudative changes of lungs were observed in physiological saline group and pcDNA 3.1 （ ＋ ） immunized group. On the contrary, similar changes were not observed in the pcDNA 3.1-mip immunized group and the pcDNA 3.1-mip/ctxB immunized group. Increased thickness of the alveolar wall and alveolar diaphragm was also observed in these two DNA vaccine immunized groups. It is concluded that protective immunity can be induced by these two DNA vaccines, in which the protective efficiency of pcDNA 3.1-mip/ctxB fusion gene is better than that of the pcDNA 3.1-mip gene.
出处
《中国人兽共患病杂志》
CAS
CSCD
北大核心
2005年第12期1075-1077,1063,共4页
Chinese Journal of Zoonoses
基金
国家自然科学基金资助(No.30300302)
