Preparation Of ALV-Jgp85Recombinant Protein Subunit Vaccine And Optimization Of Its Immunated Conditions

The previous studies in our laboratory indicated that ALV-Jgp85recombinant subunitvaccine can induce the inoculated chickens and breeding hens to produce neutralizingantibody and have certain protective effects. To be further applied to the cull of ALV-J inthe breeding flocks of China, ALV-J subunit vaccine and immunoadjuvant of CpG-ODNsneed to be optimized in their inoculated conditions. In this study, ALV-J gp85recombinantprotein using E. coli expression system was stably expressed and purified. The expressionproduct was identified by Western-blot immediated with the monoclonal antibody JE9andused as the immuned antigens of ALV-J subunit vaccine. The recombinant proteins withdifferent doses and CpG-ODNs adjuvants with different doses were inoculated into7-day–aged Hyland chickens,400-day-aged Hyland breeding hens and500-day-aged "Nongda3"breeding hens, the serum or maternal antibodies were detected. Results show that:(1) Threedifferent doses of CpG adjuvants, including200μg per hen,100μg per hen and50μg per hen,combined with ALV–J gp85recombinant protein, could all induce the breeding hens toproduce ALV–J serum antibody; and the ratios of antibody positive chicks and the antibodytiters were rising gradually and were up to the peak at28days post first inoculation (dpfi).However, the antibody titers in the dose of50μg per hen were significantly higher thanother two doses (P <0.05) and the ratios of antibody positive chicks can be up to92%(11/12). The results of yolk antibody make were accordancet with those of hens’ serumantibodies.(2) Five different doses of CpG including50μg per hen,25μg per hen,12μg perhen,6μg per hen and3μg per hen, combined with ALV–J gp85recombinant protein, couldinduce “Nongda3” hens to produce ALV–J serum antibody and then ratios of antibodypositive chicks increased gradually and up to the peak at21dpfi, but the serum antibodytiters and the ratios of antibody positive chicks in the dose of50μg per hen were significanthigher than other doses.(3) There different doses of ALV–J gp85recombinant protein including100μg per chicken,50μg per chicken and30μg per chicken, combined with CpGadjuvant of25μg per chicken, could all induce the inoculated chickens to produce serumantibody of ALV-J. But the antibody titers and the ratios of antibody positive chickens withthe dose of100μg per chicken were significantly higher than those with the other two doses(30μg and50μg groups)(P <0.05). The results indicate that dose group has the best effecton highland hens.the optioned immune doses of CpG adjuvant and gp85recombinantprotein are50μg per hen and100μg per chicken, respectively. This study can provide thescientific basis for ALV-J subunit vaccine applied in the ALV-J cull of breeding flocks.