Studies On Goose Interferon Alpha As A GPV VP3 DNA Vaccine Adjuvant

To elucidate adjuvant effect of goose interferon alpha gene (IFN-α), we generated the recombinant plasmid pcDNA3.1-goIFN-a,after which was expressed at COS-7 cells, in order to study on the adjuvant effect of goose interferon-a eukaryotic expression plasmid to Goose Parvovirus VP3 gene vaccines,goose interferon-a eukaryotic expression plasmid (pcDNA-goIFN-a) with GPV VP3 gene vaccines was inoculated to 28-day old geese at the dose of 50μg,100μg,200μg per goose respectively by intramuscular injection,the control groups included GIL2 molecular adjuvant,goIFN-a and gIL2 combined immune adjuvant,empty vector plasmid pcDNA3.1 (+), Gosling Plague Attenuated vaccine and saline, anticoagulated blood samples were harvested at 3,7,14,21,28,35,49 days to to detect the proliferation of geese T lymphocytes in peripheral blood(PBL) by T lymphocyte proliferation tests (MTT); and cruor samples harvested at 3,7,14,21,22,35,49,63,77 days to detect anti-GPV antibody by indirect ELISA methods.Obtaining the following experimental result:1. Detection of goIFN-a expression:Recombinant plasmid could be expressed in COS-7 cells, target protein was detected at 6h after transfection, then a rapid increase in protein expression,after 36h, the rate slowed.2. The reaction of T lymphocyts to ConA (OD value):The reaction of T lymphocyts to ConA (OD value):After different doses of pcDNA-goIFN-a were administrated to geese with GPV VP3 DNA vaccine, the experimental groupsT lymphocyte proliferation were at the same level at 3d, from 3d to 28d the steady rise and at 28d reached a peak,but pcDNA-VP3 group peaked at 35 d.At 28d, the OD value of the adjuvant groups were significantly (P≤0.01) higher than pcDNA-VP3 gene vaccine group, GPV attenuated group, pcDNA3.1 (+) and saline control group.GoIFN-a adjuvant groups only at 21d,35d and 49d were significantly (P≤0.05) higher than gIL2 adjuvant group, the other time pointed had no significant difference. United adjuvant group at 28d and 35d was significantly higher than goIFN-a or gIL2 adjuvant group (P≤0.05).3. The level of antibody IgG in PBL(OD):Adjuvant groups of ELISA antibody levels of the growth trend was from slow to fast, to reach the maximum value at 35d, then gradually decreased, but still significantly higher than GPV VP3 gene vaccine group and GPV attenuated group.GIL2 adjuvant group at 28d,49d and 77d was significantly higher than goIFN-a adjuvant group (P≤0.05), goIFN-a and gIL2 combined adjuvant group at 28d to 49d was significantly higher than goIFN-a or gIL2 adjuvant alone group (P≤0.01). GoIFN-a adjuvant groups, along with the different adjuvant doses showed a dose relation.The results demonstrated that COS-7 cells could expresse goIFN-a,pcDNA-goIFN-a could enhance the ability of T lymphocytes proliferation, enhance the titre of antibody IgG and neutralizing antibody in PBL, is an excellent GPV VP3 gene vaccine molecular adjuvant,goIFN-a and gIL2 combined adjuvant group had best effect, pcDNA-goIFN-a intramuscularly 200μg was better.