Studies On The Cellular Immunological Regulation Of Duck Interferon-α Eukaryotic Expression Plasmid To Ducks Immunized With DVH Attenuated Vaccine

In order to study on the cellular immunological regulation of duck interferon-αeukaryotic expression plasmid to duck,duck interferon-αeukaryotic expressionplasmid (pcDNA-DuIFN-α) was inoculated to 28-day old peking duck at the dose of50μg,100μg,200μg per duck respectively by intramuscular injection and the dose of 1μg,3μg,6μg per duck respectively by Gene Gun Bombardment and 15 days aftervaccination later duck viral hepatitis (DVH) attenuated vaccine was inoculated to theseducks.The control groups included empty vector+DVH attenuated vaccine, saline,DVH attenuated vaccine and pcDNA-DuIFN-α,and each experimental group andcontrol group contains 10 ducks. Flow cytometry method was employed to study thenumber of CD3~+ lymphocytes in peripheral blood, MTT method was used to study thetransformation ability of T lymphocyte in peripheral blood 5, 7, 14, 21, 28, 42, 56, 70days after vaccination after vaccination, obtaining the following experimental result.1. The numbers of CD3~+ lymphocyte:①Intramuscular injection: 7-56 days after vaccination the ducks inoculatedsimultaneously with pcDNA-DuIFN-αat the dose of 50μg,100μg and 200μg andDVH attenuated vaccine were extremely significantly higher (P≤0.01) than the ducksinoculated with physiological saline. 7-42 days after vaccination 100μg group wasextremely significantly (P≤0.01) and 50μg and 200μg group was significantly(P≤0.05) higher than the empty plasmid+DVH attenuated vaccine, DVH attenuated vaccine and pcDNA-DuIFN-αgroup. 7-42 days after vaccination 100αg group wassignificantly higher (P≤0.05) than 50μg and 200μg group, 14-28 days aftervaccination 50μg group was little higher than 200μg group.②Gene gun bombardment: 7-56 days after vaccination the ducks inoculatedsimultaneously with pcDNA-DuIFN-αat the dose of 1μg,3μg and 6μg and DVHattenuated vaccine were extremely significantly higher (P≤0.01) than the ducksinoculated with physiological saline. 21-56 days after vaccination 3μg group, 21 daysafter vaccination 1μg and 6μg group was extremely significantly higher (P≤0.01) thanempty plasmid+DVH attenuated vaccine, DVH attenuated vaccine andpcDNA-DuIFN-αgroup. 28-42 days after vaccination 3μg group was little higher than1μg and 6μg group.7-14 and 28-56 days after vaccination 1μg group was little higherthan 6μg group.③Comparison with intramuscular injection and gene gun bombardment: 14-21days after vaccination the group by intramuscular injection at the dose of 100μg wassignificantly higher(P≤0.05)than the 3 groups by gene gun bombardment.21 days aftervaccination 1μg,3μg and 6μg gene gun group was significantly higher (P≤0.05) than200μg intramuscular injection group.④Comparison with the control groups: there was no difference among DVHattenuated vaccine, pcDNA-DuIFN-αand empty plasmid+DVH attenuated vaccinegroups, which were extremely significantly higher (P≤0.01) than physiology salinecontrol group 7-56 days after vaccination.2.The reaction of T lymphocytes to ConA (OD values):①Intramuscular injection: 5-70 days after vaccination the ducks inoculatedsimultaneously with pcDNA-DuIFN-αat the dose of 50μg,100μg and 200μg andDVH attenuated vaccine were extremely significantly higher (P≤0.01) than the ducksinoculated with physiological saline, and 21-56 days after vaccination extremelysignificantly higher (P≤0.01) than empty plasmid+DVH attenuated vaccine, DVHattenuated vaccine and pcDNA-DuIFN-αgroup. There was no significant differenceduring 50μg,100μg and 200μg groups, and 5-14 days after vaccination and 28-42days after vaccination 100μg and 50μg group was little higher 200μg group.②Gene gun bombardment: 5-70 days after vaccination the ducks inoculatedsimultaneously with pcDNA-DuIFN-αat the dose of 1μg,3μg and 6μg and DVH attenuated vaccine were extremely significantly higher (P≤0.01) than the ducksinoculated with physiological saline. 14-42 days after vaccination 3μg group, 21-42days after vaccination 1μg and 6μg group was significantly higher (P≤0.05) thanempty plasmid+DVH attenuated vaccine, DVH attenuated vaccine andpcDNA-DuIFN-αgroup. 14-42 days after vaccination 3μg group was significantlyhigher (P≤0.05) than 1μg and 6μg group,between which there was no difference.14-28 days after vaccination 6μg group was little higher than 1μg group.③Comparison with intramuscular injection and gene gun bombardment: 14 daysafter vaccination the group by gene gun bombardment at the dose of 3μg was littlehigher than the 3 groups by intramuscular injection.28-70 days after vaccination 50μgand 100μg, and 42-70 days after vaccination 200μg intramuscular injection group wassignificantly higher (P≤0.05) than 1μg and 6μg gene gun bombardment group.④Comparison with the control groups: there was no difference during DVHattenuated vaccine, pcDNA-DuIFN-αand empty plasmid+DVH attenuated vaccinegroups, which were extremely significantly higher (P≤0.01) than physiology salinecontrol group. 14-42 days after vaccination DVH attenuated vaccine and emptyplasmid+DVH attenuated vaccine group was little higher than pcDNA-DuIFN-αgroup and 21-56d was little higher than DVH attenuated vaccine group.The results demonstrated that pcDNA-DuIFN-αcould significantly promote theduck cellular immunity, significantly enhance the duck cellular immunity induced byDVH attenuated vaccine.PcDNA-DuIFN-αwas an excellent molecular immunologicalpromoter of duck and was an excellent DVH attenuated vaccine molecularimmunological adjuvant. Best result could be obtained at the dose of 100μgpcDNA-DuIFN-αby intramuscular injection and 3μg pcDNA-DuIFN-αby gene gunbombardment in epdermis.