HSV-2gD模拟抗原表位、HBsAg与IL-18融合蛋白DNA疫苗的免疫效果观察

The immune responses induced by the DNA vaccine expressing fusion protein of HSV-2gD-HBsAg and IL-18

目的:研究串联重组核酸疫苗pc(pcDNA3.1)-S(HBsAg)-P6-IL18和pc(pcDNA3.1)-S(HBsAg)-NP6-IL18对机体的免疫效果,P6是我们前期采用噬菌体展示技术筛选出的HSV-2gD的模拟抗原表位,NP6为与HSV-2gD模拟抗原表位P6最相似的天然抗原表位序列。方法:分别将空质粒pcDNA3.1(阴性对照组)和构建的真核表达质粒pc-S-P6-IL18和pc-S-NP6-IL18肌内注射免疫接种BALB/c小鼠3次,每次间隔2周。末次免疫后2周眼眶静脉采血,ELISA法检测小鼠血清特异性抗体滴度、IFN-γ及IL-18含量;末次免疫后一月,处死小鼠,无菌分离脾脏,用刀豆蛋白A刺激淋巴细胞,采用MTT法测定脾淋巴细胞增殖率。结果:重组核酸疫苗pc-S-P6-IL18和pc-S-NP6-IL18免疫小鼠后可刺激血清特异性抗体(抗HBsAg抗体和抗HSV-2gD模拟表位抗体)的产生,与阴性对照组相比可诱导分泌较高水平的IFN-γ和IL-18,可促进小鼠脾淋巴细胞的增殖。结论:重组核酸疫苗pc-S-P6-IL18和pc-S-NP6-IL18能诱导较强的细胞免疫和体液免疫,可用于今后预防HBV和HSV-2感染的研究。

Objective：To evaluate humoral and cellular immune responses induced by the DNA vaccine expressing fusion protein of HSV-2gD-HBsAg and IL-18 in BALB/c mice.The P6 is mimotope of HSV-2gD,the NP6 is the sequence of natural HSV-2gD which is similar to P6.Methods：The plasmid pcDNA3.1（negative control） and the recombinant plasmids pc-S-P6-IL18 and pc-S-NP6-IL18 were inoculated into BALB/c mice by intramuscular injection for three times,twice a week.Two weeks after the last vaccination,the level of specific IgG antibody,IFN-γ and IL-18 were measured by ELISA;one month after the last vaccination,spleen cells of vaccinated mice were separated and the proliferative response of spleen lymphocytes was stimulated by ConA and measured by MTT.Results：After inoculated by pc-S-P6-IL18 and pc-S-NP6-IL18 vaccines,the mice could produce higher level of splenocyte proliferative response and secrected IFN-γ,IL-18 and specific antibody than by pcDNA 3.1.Conclusion：The recombinants of pc-S-P6-IL18 and pc-S-NP6-IL18 can effectively induce humoral and cellular immune responses,which can offered the basic study for preventing against the infections of hepatitis B virus and herpes simplex virus type 2.