Analysis of humoral immune response and cytokines in chickens vaccinated with Eimeria brunetti apical membrane antigen-1 (EbAMA1) DNA vaccine

Abstract

This study aimed to determine the changes of cytokines, specific serum IgG and several parameters in chickens vaccinated with DNA vaccine encoding Eimeria brunetti apical membrane antigen-1 (EbAMA1) antigen. Two-week-old chickens were divided into five groups (four groups for experiment) randomly. Experimental groups of chickens were immunized with DNA vaccine while control group of chickens were injected with pVAX1 plasmid alone or TE buffer solution. All immunizations were boosted 2weeks later. The EbAMA1 specific IgG antibody responses were measured at weeks 1–6 post-second immunizations and several parameters were also identified. The result showed that the antibody titers in chickens vaccinated with DNA vaccines were significantly different from those of the control groups 1week after the second immunization and reached the maximum values 3weeks post-second immunization. IFN-γ concentration was increased the highest level against EbAMA1 of all chickens vaccinated with vaccines up to 56-fold, follow by the specific IgG antibody levels were increased 10–17-fold compared with those of TE solution and plasmid (pVAX1) control chickens 1–6weeks post-second immunization. In case of the levels of IL-10 and IL-17 was increased in experimental chickens with 4–5-fold. Even though it was statistically significant, TGF-β and IL-4 levels were higher in vaccinated than unvaccinated chickens. The results suggested that DNA vaccines encoding E. brunetti apical membrane antigen-1 (EbAMA1) could increase serum specific IgG antibody and cytokines concentration and could give protection against E. brunetti infection.