构建获得含有H9亚型禽流感病毒血凝素(HA)基因的重组真核表达质粒pCAGGS-HA。重组质粒电转化减毒鼠伤寒沙门氏菌SL7207,获得重组沙门氏菌SL7207(pCAGGS-HA)。重组菌SL7207(pCAGGS-HA)以5×109cfu的剂量2次口服免疫1日龄商品代伊莎褐蛋鸡后,再以油乳剂灭活疫苗加强免疫1次,并设立重组菌单独免疫组、灭活苗免疫组、空载体免疫组及空白对照组。联合免疫组和重组菌单独免疫组的小肠黏膜抗体效价与其他组之间存在显著差异(P<0.05),且两组的攻毒免疫保护水平与空载体组之间差异显著(P<0.05),其中联合免疫组的免疫保护率最高,达100%,而灭活苗免疫组保护率为80%,表明减毒沙门氏菌介导的H9亚型禽流感DNA疫苗与灭活疫苗联合应用具有良好的免疫协同作用。
The hemagglutinin protein(HA) gene of H9N2 subtype avian influenza virus (AIV) was obtained by restriction digestion from the recombinant plasmid pET-HA,and subcloned into pCAGGS vector.The recombinant plasmid pCAGGS-HA was transformed into the attenuated Salmonella typhimurium SL7207,and the recombinant was designated as SL7207(pCAGGS-HA).One-day-old commercial ISA brown chickens were immunized with SL7207(pCAGGS-HA) plus killed oil-emulsified vaccine of AIV,SL7207(pCAGGS-HA),killed oilemulsified vaccine o...