猪瘟疫苗冻干保护剂的筛选及免疫效果评价

Screening of freeze-drying protectants of swine fever virus vaccine and effect evaluation for oral immunization

为了筛选耐热性能好、能提高猪瘟病毒(SFV)疫苗经口服途径免疫效果的冻干保护剂,配比不同组分的冻干保护剂与黏膜佐剂LTRG蛋白、SFV按比例混合,通过对冻干工艺的优化,制备了4种.SFV的冻干苗;口服免疫小鼠,测定血清IgG和粘膜IgA抗体效价。结果表明:试验2组即甘氨酸+明胶组和试验4组即明胶组的外观形态较好,水溶后呈现澄清的状态;试验2组和试验4组的冻干苗经口服免疫,诱导小鼠产生的IgG抗体水平显著高于SFV组、SFV+LT组及其他试验组(P<0.01)。二免7 d试验2组小鼠肛试子IgA抗体显著高于其他组(P<0.01),且小鼠脾脏IFN-γ和IL-4细胞因子的表达量也极显著高于其他组(P<0.01)。研究初步筛选出第2组配方,即以甘氨酸和明胶配伍作为猪瘟口服疫苗冻干保护剂,为研制口服途径免疫的猪瘟疫苗奠定了基础。

In order to select a freeze-drying protectant having a good heat tolerance and improving oral im- munization of swine fever virus （ SFV ） vaccine, freeze-drying proteetants with different components were mixed with mucosal adjuvant LTRG protein and SFV in proportion, and 4 kinds of lyophilized SFV vaccines were pre- pared via optimization of freeze-drying conditions;The vaccines were used for oral immunization of mice and the serum IgG and mucosal IgA antibody valences were determined. The results showed that Group 2 （ glycine ＋ ge- latin） and Group 4 （gelatin）had a relatively good appearance and water solubility;After oral immunization the mice-produced IgG antibody levels in Groups 2 and 4 were very significantly higher than those in other groups, and at 7 days after the second oral immunization the anal swab＇ s IgA antibody level in Group 2 was very signifi- cantly higher than that in other groups, and moreover, the spleens＇ IFN-γ and IL-4 cytokine expression levels in Group 2 were very significantly higher than those in other groups. It was concluded that gelatin and glyeine could be used as freeze-drying protectants of oral SFV vaccine.