pVAX1/IL-18对日本血吸虫DNA疫苗效果影响的初步研究

Preliminary studies on effect of pVAX1/IL-18 induced pVAX1/SjRPS4·CB vaccine immunoreaction of Schistosomiasis japonica

目的探讨pVAX1/IL-18对日本血吸虫pVAX1/SjRPS4·CB疫苗免疫保护效果的影响。方法将BALB/c小鼠随机分为NS组、pVAX1空质粒组、pVAX1/IL-18组、pVAX1/SjRPS4·CB组、pVAX1/SjRPS4·CB+pVAX1/IL-18组,每组12只。每组小鼠在左后腿股四头肌注射相对应质粒100μg或者等剂量生理盐水,隔2W加强1次,共注射3次。末次免疫后3周腹部贴片感染小鼠。感染后8周剖杀小鼠,用ELISA法检测小鼠特异性抗体IgG,计算减虫率、肝组织减卵率、肠减卵率、每雌减卵率。结果 pVAX1/SjRPS4·CB、pVAX1/IL-18联合免疫小鼠后,IgG滴度为1∶12 800,高于单独免疫组;减虫率、肝组织减卵率、肠减卵率、每雌减卵率与其他组相比差异均有统计学意义。结论 pVAX1/IL-18对日本血吸虫DNA疫苗具有明显增效作用。

In this paper,the influence of pVAX1/IL-18 as an adjuvant on the pVAX1/Sj RPS4·CB vaccine against Schistosoma japonicum infection was explored.Seventy BABL/c mice were randomly divided into five groups as normal saline(NS)control group,pVAX1 group,pVAX1/IL-18 group,pVAX1/Sj RPS4·CB vaccine group,pVAX1/Sj RPS4·CB vaccine and pVAX1/IL-18 group.100μg normal saline or plasmids were respectively injected intramuscularly for three times with two weeks interval.Three weeks after the final injection,each mouse was challenged with Schistosoma japonicum cercariae(20±1)infection on the abdomen.ELISA was used to detect the induced specific antibody.Adult worm burden reduction was calculated according to the adult worms in mice.Intestine eggs reduced rate,liver eggs reduced rate and per female worm eggs reduced rate were calculated according to the number of Intestine eggs,liver eggs,and per female worm eggs.Eight weeks after the infection,the IgG antibody levels of the mice with pVAX1/Sj RPS4·CB vaccine and pVAX1/IL-18 group was significantly higher than other groups.Combined pVAX1/Sj RPS4·CB vaccine and pVAX1/IL-18 group had shown significant decreases in adults worm burden,liver eggs,intestine eggs and uterus eggs,with those being reduced about 52%,63%,67%and 52%.The reduction rates in the above combined group were all significantly higher than other three experimental groups(P<0.05).pVAX1/IL-18 using as an adjuvant can increase the protection effect of Sj RPS4·CB vaccine against Schistosoma japonicum infection.