Abstract: In this study, the recombinant chicken interleukin-2 (rchIL-2) was successfully produced in the pBAD/His B expression system induced by L-(+)-arabinose. By SDS-PAGE analysis, the observed molecular weight of rchIL-2 fusion protein without the signal peptide was 18 kD. Monoclonal and polyclonal antibodies specific for rchIL-2 were produced. These antibodies were used to develop a mAb-based antigen capture ELISA (AC-ELISA). Based on the constructed AC-ELISA, in vitro kinetics of endogenous chicken IL-2 production were detected. The soluble rchIL-2 protein purified under native conditions was shown to activate the proliferation of chicken lymphocytes stimulated by Con A for 24 h in a dose-dependent manner. This activity cannot be neutralized by mAbs to chIL-2, but can be neutralized by anti-chIL-2 polyclonal antibody. These results demonstrated that the E.coli-derived rchIL-2 and polyclonal antibody to chIL-2 have bioactivity.

Key words: Chicken, Interleukin-2, Bioactivity, Monoclonal antibody, Polyclonal antibody, Ag capture ELISA