Abstract：To examine the bioactivity of rEIL-18 obtained from E.coli, we evaluated if rEIL-18 showed a synergistic effect with rhIL-12 for the induction of EIFN-gamma gene expression from equine PBMCs using by real-time RT-PCR. REIL-18 could induce EIFN-gammamRNA expression from equine PBMCs about 20-fold higher than that of negative control in the presence of rhIL-12. And the effect to induce EIFN-gamma gene expression was dose-dependent with rEIL-18 in a fixed concentration of rhIL-12. We also evaluated if 9 anti-rEIL-18 monoclonal antibodies (mAbs) could neutralize the bioactivity of rEIL-18. One of 9 mAbs could neutralize rEIL-18 bioactivity and its effect was dose-dependent. The results showed that rEIL-18 had bioactivity commensurate with the native molecule, as they were neutralized by mAbs against rEIL-18.
