Generation and characterization of a monoclonal antibody (1C5) to human migration inhibitory factor (MIF).

A monoclonal antibody was raised in mice against human MIF of the Mr 14,000 kd, produced by Concanavalin A-stimulated peripheral blood mononuclear cells. A hybridoma (1C5) secreting an IgG 1 antibody was selected which binds, yet does not neutralize MIF in the macrophage migration assay. MIF activity may be released from immobilized antibodies by acidic buffer elution. The eluate consists of three major bands at Mr 8,000, 14,000 and 28,000 as revealed by SDS-polyacrylamide gel electrophoresis and molecular sieve chromatography (HPLC). By radioimmunoassay and enzyme-linked immunoassay, it could be shown that the antibody binds material with isoelectric points of 4.5 to 5.0 and of 3.0, which coincides precisely with the biological activities. Similar congruencies between the distribution of biologically reactive and binding material were found in molecular sieve and ion exchange chromatography. It is concluded that the antibody 1C5 reacts with most molecular weight entities of MIF which seem to be structurally related and which display similar characteristics as described for guinea pig and mouse MIF.