空肠弯曲菌pcDNA3.1(-)-peb1A壳聚糖佐剂疫苗对小鼠免疫原性和保护性研究

目的:研究空肠弯曲菌pcDNA3.1(-)-peb1A壳聚糖佐剂疫苗的免疫原性和保护性。方法:健康雄性昆明小鼠分为实验组和对照组。实验组设pcDNA3.1(-)-peb1A组3个剂量和壳聚糖-pcDNA3.1(-)-peb1A组3个剂量;对照组设空载体pcDNA3.1(-)(100μg/100μl)组和生理盐水(NS)组,各组均采用小鼠股四头肌注射法。在第0、10、20天免疫,于每次免疫后第10天采集各组小鼠血清,以间接ELISA法检测血清中特异性IgM、IgG的含量。分离各组小鼠脾淋巴细胞包被细胞培养板,以细胞ELISA法检测小鼠脾淋巴细胞CD20、CD21表达水平。设空肠弯曲菌液灌胃攻击免疫后小鼠,检测肠道分泌液细菌培养数量。结果:裸DNA组和壳聚糖-DNA组各组特异性IgG水平均高于两对照组(P<0.05)。裸DNA组和壳聚糖-DNA组小鼠脾淋巴细胞CD20、CD21表达水平均高于两对照组(P<0.05),壳聚糖-DNA组高于裸DNA组(P<0.05)。肠道分泌液细菌培养结果细菌指数裸DNA组的低于两对照组;佐剂DNA组低于裸DNA组。结论:重组质粒pcDNA3.1(-)-peb1A经肌肉注射免疫小鼠,具有较好的免疫原性和保护作用,壳聚糖能增强pcDNA3.1(-)-peblA的免疫原性,有望成为空肠弯曲菌基因疫苗的候选佐剂。

Immunogenicity and immunoprotection of the Campylobacter jejuni pcDNA3.1(-)-peb1A vaccine with chitosan in mice

Objective:Evaluated the immune effects of pcDNA3.1(-)-peb1A with chitosan in mice.Methods:Healthy male KM mice were divided into experimental groups and control groups.The former contained nake pcDNA3.1(-)-peb1A and chitosan-pcDNA3.1(-)-peb1A vaccine group.The latter included the pcDNA3.1(-)(100 μg/100 μl) control group and normal saline(NS) control group.Every group was immunized through musculus quadriceps fexoris injection.Immunized mice in 0th,10th,20th day.On 10th day after each immunization,the serum were collected in each group,spleen lymphocytes were isolated and used them to coat the cell culture plate.The level of specific IgM and IgG antibody in serum of each KM mice were detected with indirect ELISA.The level of CD20 and CD21 were detectd with cellular ELISA of the optimization group.Results:Statistically increased level of serum specific IgG antibody were observed in nake pcDNA3.1(-)-peb1A and chitosan-pcDNA3.1(-)-peb1A group compared with the two control groups(P<0.05).The 100 μg subgroup had the highest serum level in nake pcDNA3.1(-)-peb1A and chitosan-pcDNA3.1(-)-peb1A vaccine group(P<0.05).The level of chitosan-pcDNA3.1(-)-peb1A group increased more in the same dosage(100 μg) than nake pcDNA3.1(-)-peb1A group(P<0.05).The expression levels of CD20 and CD21 in the immunized mice in nake DNA group and chitosan-DNA group were higher than two control groups(P<0.05).And chitosan-DNA group was higher than nake DNA group(P<0.05).Conclusion:pcDNA3.1(-)-peblA had good immunogenicity via intramuscular injection immunize mice.Chitosan can strengthen the immunogenicity of DNA vaccine.The study signifies the potential of chitosan as DNA vaccine adjuvant for effective immunization through intramuscular injection route.