Comparison of Serum and Egg Yolk Antibodies Induced by Different Doses of CpG-ODN Adjuvant Combined with ALV-J gp85 Recombinant Proteins in Breeding Hens(Gallus domesticus)
Abstract：To compare the effects of three different doses of CpG oligonucleotide (CpG-ODN) adjuvants combined with subgroup J Avian leukosis virus (ALV-J) gp85 recombinant protein on serum and egg yolk antibodies in breeding hens(Gallus domesticus), the recombinant protein containing ALV-J gp85 gene was prepared using the prokaryotic expression system and vaccinated combining with three different doses of CpG-ODN adjuvant into adult Hy-line Brown parent breeding hens, the booster immunization was conducted with two weeks interval. The serum antibodies and the egg yolk antibodies against ALV-J were detected weekly using ALV-J antibody kits from 1 day post inoculation to 49 day post inoculation and the data were statistically analyzed with ANOVA software. The results of protein gel electrophoresis showed that the recombinant protein containing gp85 gene of ALV-J was successfully prepared with prokaryotic expression system and the size of the recombinant protein was 45 kD; the Western blotting analysis indicated that the purified recombinant protein could specifically bind with the monoclonal antibody JE9 of ALV-J gp85 protein; the serum antibodies in breeding hens were successfully induced by three different doses of CpG combining with the recombinant gp85 protein, the serum antibody titers were increasing from the first post inoculation and reached a peak at the 28th day post first inoculation and then decreased slightly. Between three vaccinated groups, the antibody titers in the 50 μg CpG dose group were higher than those in the other two vaccinated groups. The ratio of positive antibodies in the 50 μg CpG dose group was up to 92%, but it was up to 80% in the 100 μg CpG dose group and only 67% in the 200 μg CpG dose group, respectively. The egg yolk antibodies against ALV-J in three vaccinated groups were successfully detected from the 3rd week to the 7th week post first inoculation; the antibody titers in the 50 μg CpG dose group were optimized at the 4th, the 6th and the 7th week post the first inoculation, which also were better than those in the other two vaccinated groups. Based on these results, it can be concluded that three does of CpG combining the recombinant protein containing gp85 gene of ALV-J could induce the vaccinated breeding hens to produce serum antibody and maternal antibody against ALV-J and the dose of 50 μg per hen was better than that of the other two doses. These results can provide a scientific basis for the application of CpG adjuvants combing with ALV-J gp85 subunits vaccine in blocking ALV-J early infection with maternal antibodies in breeding hens.
