Interleukin 8 enhances the immune response of ducks to avian influenza vaccine

Interleukins are reported to be valuable immunostimulants in enhancing the immune efficiency of conventional vaccines. In this study, the effect of expression of interleukin 8 (IL-8) on the immune response of ducks to avian influenza vaccine was investigated. The results showed that the serum antibody titer, lymphocyte transformation efficiency and serum interferon gamma (IFN-γ) level of ducks injected with avian influenza vaccine along with a plasmid expressing duck IL-8 were higher than those of ducks injected with conventional immunostimulant Astragalus polysaccharide (APS) or empty plasmid. Therefore, the duck IL-8 may be used as a good immunostimulant to enhance the immune efficiency of avian influenza vaccine in ducks.