[Preparation and biologic activity study of (125);I-labeled anti-MIF monoclonal antibody].

Aim: Find the method to make (125);I-labeled anti-Macrophage migration inhibitory factor (MIF) mAb and investigate its in vivo biologic activity.

Methods: (1)Anti-MIF mAb was radioiodinated with Na(125);I by Iodogen method followed by purified using Sephadex G-25 gelfiltration chromatography. The labeling efficiency of (125);I-labeled anti-MIF mAb was measured. The radiochemicalpurity and the stability were assayed by paper chromatograph. (2)The immunocompetence and the in vivo biologic activity were evaluated by using ELISA and modified MMI. (3)The in vivo biodistribution of (125);I-labeled anti-MIF mAb was detected using mouse model.

Results: (1)The 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 Na(125);I to Iodogen-Ab mix; kept reaction at RT for 10-15 min. The labeling efficiency of (125);I-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 (125);I-labeled anti-MIF mAb was still 90.36% after kept at 4DegreesCelsius for three days. (2)(125);I-mMIF mAb could bind to its ligand MIF in vivo with their unaffected immunocompetence and biologic activity. (3)The lungs, livers, spleens and kidneys of the experimental mice had the relative high radiocounting.

Conclusion: These results demonstrate that the (125);I-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 (125);I-labeled anti-mMIF mAb had the potential ability to be used in further radioimmunoimaging and targeted therapy research.