狂犬病病毒糖/核蛋白基因疫苗和IL-18在犬的免疫试验研究

目的　检测狂犬病病毒糖 /核蛋白“二价”基因疫苗及IL - 18在犬体内的免疫效果 ,并确定不同包裹剂对基因疫苗免疫效果的影响。方法　本试验以 pIRES1neo和人用灭活苗分别作为阴、阳性对照 ,以糖 /核蛋白双基因共表达载体 pIGN单独或与IL - 18的真核表达载体pIIL18混合 ,以司苯 -甘油混合或以生理盐水溶液形式 ,按每条犬 2 0 0 μgDNA/ml,接种 3次 (其中 1组第 3次加强免疫时采用浓缩的狂犬病灭活苗 ) ,间隔 2周的免疫程序 ,经股四头肌进行注射免疫。通过间接ELISA、细胞中和试验及淋巴细胞转化试验分别检测体液和细胞免疫水平。结果与结论　结果显示 ,1.所有试验组在第 3次加强免疫后特异性抗体和中和抗体水平显著高于阴性对照组 ;pIGN pIIL18组诱导的细胞免疫水平高于无 pIIL18的 pIGN免疫组 ;2 .以司苯 -甘油作为包裹剂的基因疫苗诱导产生的免疫应答水平与裸质粒 (生理盐水溶液 )形式的基因疫苗间无显著差异 ;3.以糖 /核蛋白二价基因疫苗pIGN作为基础免疫 ,再以狂犬病浓缩灭活苗加强免疫后 ,能迅速诱导较高的体液免疫应答水平。以上结果说明 ,狂犬病病毒糖 /核蛋白“二价”DNA疫苗具有实际应用于免疫预防的潜力。

Immunological experiment on dogs by Rabies virus glycoprotein/nucleoprotein DNA vaccine and IL-18

To assay the immunological effect of rabies virus glycoprotein and nucleoprotein bivalent DNA vaccine and IL 18 on dogs. The double gene vector pIGN alone or in combination with IL 18 in physiological saline or mixed with span glycerol were used to inoculate dogs in quadriceps. Each dog was injected with a dose of 200μg/mL for two times at 2 weeks intervals. The third booster injection was carried out two weeks later by either the same DNA vaccine or a third dose of human inactivated rabies vaccine. Specific immune response was assayed by titration of specific antibodies, neutralizing antibodies and lymphocyte transformation assay. Results showed that (1) the booster injection stimulated a significant anamnestic response in all groups. However, there was no significant difference between groups although pIGN pIIL18 induced higher cell mediated immunity than those without pIIL18; (2) there was no difference in immunological response between the span glycerol DNA vaccine and the DNA vaccine in physiological saline; (3) high immune response could be swiftly induced by a third dose of concentrated rabies vaccine booster in the group primed twice with DNA vaccine. All these indicated that the bivalent DNA vaccine can be applied to immunize dogs in the form of naked plasmids or in the form of mixture with pIIL18. It was demonstrated that bivalent DNA vaccine has the potential in place of inactivated and attenuated vaccines.