Generation and characterization of monoclonal antibodies against mature hepcidin and its application to neutralization and quantitative alteration assay

ABSTRACT Hepcidin regulates the quantity of ferroportin (FPN) on cellular membrane. In our cell assay expressing ferroportin labeled with green fluorescence, FPN was internalized and degraded only after treatment with hepcidin-25, not hepcidin-22 or hepcidin-20, leading to accumulation of cellular iron. Thus we generated murine monoclonal antibodies (mAbs) against hepcidin-25, and then characterized and validated their functions. Among them, several mAbs showed a neutralizing activity that may prevent ferroportin internalization induced by hepcidin-25. To measure hepcidin level in various fluids, mAbs specific for human and rat hepcidin-25 were selected. As for rat, a sandwich ELISA developed using clone rHN1 as capture antibody and biotinylated clone mHW1 as a detection reagent had high sensitivity, allowing for the detection of 1-100 ng/mL of hepcidin-25. Rat hepcidin-25 level in plasma was measured at an average concentration of 63.0 ng/mL in healthy condition, and at 218.2 ng/mL after stimulation of lipopolysaccharide.