关键词: α-干扰素基因疫苗, 荧光定量PCR, 鸭瘟病毒

Abstract: Yingtaogu ducks were immunized once with 50, 100, 200 μg pcDNA-SDIFN-α DNA vaccine respectively by the route of intramuscular injection with PBS, pcDNA3.1(+). We attenuated duck plague virus vaccine as control, challenged with duck plague virus (DPV) after immunization 15 days later and collected the peripheral blood samples at 2 h, 6 h, 12 h, 24 h, 3 d, 6 d, 9 d, 14 d, 22 d, 26 d, 33 d and 40 d, as well as tissues or organs of dead ducks. The real-time fluorescence quantitative PCR was used to detect the number of DPV-DNA in blood and tissues or organs. Results:①Ducks of pcDNA-SDIFN-α groups and attenuated DPV vaccine groups were not dead, but one duck of PBS and pcDNA 3.1(+) groups was dead. The DPV-DNA can be detected from heart, liver, spleen, kidney, pancreas and all intestines, and the quantity of DPV-DNA was much more than the peripheral blood of pcDNA-SDIFN-α groups;②The quantity of DPV-DNA in peripheral blood was significantly (P <0.05) or highly significant (P<0.01) different among pcDNA-SDIFN-α groups and PBS group, pcDNA3.1(+) group. The quantity of DPV-DNA in peripheral blood was significantly (P<0.05) different between attenuated DPV vaccine group. The quantity of DPV-DNA in peripheral blood was not different (P>0.05) between 50, 100 μg group and 200 μg group. The quantity of DPV-DNA of 200 μg group was the least, 100 μg group was more, 50 μg group was the most. Conclusion:pcDNA-SDIFN-α immunized by intramuscular injection can counteract the infection of DPV and show some dose-dependent relationship.

Key words: interferon-α gene vaccine, fluorescence quantitative PCR, duck plague virus