Preparation and biologic activity study of ~(125)I-labeled anti-MIF monoclonal antibody

AIM: Find the method to make 125Ⅰ-labeled anti-Macrophage migration inhibitory factor(MIF) mAb and investigate its in vivo biologic activity.METHODS: ①Anti-MIF mAb was radioiodinated with Na125Ⅰ by Iodogen method followed by purified using Sephadex G-25 gelfiltration chromatography.The labeling efficiency of 125Ⅰ-labeled anti-MIF mAb was measured.The radiochemicalpurity and the stability were assayed by paper chromatograph.②The immunocompetence and the in vivo biologic activity were evaluated by using ELISA and modified MMI.③The in vivo biodistribution of 125Ⅰ-labeled anti-MIF mAb was detected using mouse model.RESULTS: ①The best reaction condition for labeling was: Mixed 40-100 μg Iodogen with 20-50 μg anti-MIF mAb(Iodogen(m): anti-MIF mAb(m)=2∶1);added 15-30 MBq Na125Ⅰ to Iodogen-Ab mix;kept reaction at RT for 10-15 min.The labeling efficiency of 125Ⅰ-labeled anti-MIF mAb was(90.40±3.34)%.The radiochemicalpurity was(97.60±1.14)%.And the specific activity was 12.2-26.0 MBq/μg.The radiochemicalpurity of 125Ⅰ-labeled anti-MIF mAb was still 90.36% after kept at 4℃ for three days.②125I-mMIF mAb could bind to its ligand MIF in vivo with their unaffected immunocompetence and biologic activity.③The lungs,livers,spleens and kidneys of the experimental mice had the relative high radiocounting.CONCLUSION: These results demonstrate that the 125Ⅰ-labeled anti-mMIF mAb made by Iodogen method using the reaction condition introduced in this study had the characteristic including high labeling efficiency,high radiochemicalpurit,good in vitro stability and stable in vivo biologic activity.This study suggests that 125Ⅰ-labeled anti-mMIF mAb had the potential ability to be used in further radioimmunoimaging and targeted therapy research.