关键词: 犬瘟热, 基因疫苗, 犬瘟热病毒H基因, 犬瘟热病毒F基因, 犬瘟热病毒N基因

Abstract: Firstly,the mice were immuned with the expression plasmids by intramuscular injection. The first group was inoculated with pVAXLPH, the second group was inoculated with pVAXLPF, the third group was inoculated with pVAXLPH and pVAXLPF, the fourth group was inoculated with pVAXLPH, pVAXLPF and pVAXLPN, the fifth group was inoculated with empty vector DNA pVAX1 as negative control, and the sixth was inoculated with attenuated CDV vaccine as positive control. A total of three inoculations were performed at biweekly intervals. Indirect ELISA, neutralization and lymphocyte transformation assays were employed to determine the immunological response. As a result, the mice inoculated with these plasmids developed humoral and cellular immune responses against CDV. pVAXLPN did induce cell-mediated immunity, at high level. Tow weeks after the last injection ,the ELISA titers against CDV of the fourth group is 0.332, and SN titers against CDV of the fourth group is 1∶(4-16), the OD570 of lympho-spleencytes proliferation against CDV and ConA stimulation of the the fourth group is 0.384 and 0.356, respectively, the results of CD4⁺/CD8⁺ of the the fourth group is 2.05±0.38.Secondly, twenty 45-60 day-old CDV seronegative dogs were divided into four groups. All dogs in each group were immunized for 3 times. The first group was injected with a mixture of 200 μg of all the three plasmids containing the H, F and N gene, three times at biweekly intervals, the second group was injected with a mixture of 200 μg of all the three plasmids two times and with attenuated CDV vaccine once, the third group were injected with pVAX1 plasmid as negative control, and the fourth group was injected with attenuated CDV vaccine as positive control. Indirect ELISA, neutralization and lymphocyte transformation assays were employed to determine the immunological response. Two weeks after the last injection,the ELISA titers and SN titers against CDV of the first group is 0.296 and 1∶(8-32), respectively ;And the ELISA titers and SN titers against CDV of the second group is 0.433 and 1∶(16-64), respectively. As a result, the dogs inoculated with these plasmids developed humoral and cellular immune responses against CDV. The induced immune response in second group was higher than that in the first group.

Key words: CDV, DNA vaccine, CDV H, CDV F, CDV N