Preparation of hIL-31 polyclonal antibodies and identification of their biological activity

Objective To prepare hIL-31 polyclonal antibodies and identify their biological activity. Methods The recombinant protein was achieved in E.coli through IPTG induction, purified with Ni beads, and then analyzed by SDS-PAGE and Western blot. Rabbits were immunized with hIL-31 protein to prepare hIL-31 polyclonal antibodies. The specificity and titer of the antibodies were detected by Western blot and ELISA, respectively. The blocking effect of hIL-31 polyclonal antibodies on secretion of MIP-3β was detected by real-time PCR. Results hIL-31 was greatly expressed in E.coli after IPTG induction. The recombinant protein was about 30% of the total expressed products in E.coli. The polyclonal antibodies were successfully prepared with a higher titer (1 ∶ 2 560) and were capable of blocking the secretion of MIP-3β in stimulated by IL-31. Conclusions hIL-31 recombinant protein expressed in E.coli can stimulate the production of antibodies in rabbits. hIL-31 polyclonal antibodies have a higher titer and biological activity to block the action of IL-31.