Bm-MIF (Bm-MIF) and human MIF (hu-MIF) induce changes in macrophage migration. Human peripheral blood monocytes/macrophages were placed in the top well of a microchemotaxis chamber, as outlined in Materials and Methods. The level of migration of cells exposed to human MIF (A and C), Bm-MIF (B and D), or medium was assessed after 3 h of incubation at 37°C. The level of migration of cells in medium alone was designated 100% and is indicated by the arrow in each panel. Each series of test and control treatments was carried out in triplicate on cells isolated from three to six healthy donors. Error bars represent standard errors of the means for the individual donors. (A) Human MIF at three concentrations in the top wells or the bottom wells of the chemotaxis chamber. (B) Bm-MIF at various concentrations in the top wells or the bottom wells of the chemotaxis chamber. (C) Specific inhibition of human MIF-induced migration with monoclonal antibody IIID-9. The migration induced by 1 ng of human MIF per ml in the bottom chamber is shown by the first bar and by the dashed line. IIID-9 or its corresponding isotype-matched control monoclonal antibody (Ctrl IgG) was preincubated with 1 ng of human MIF per ml for 1 h at 25°C and then placed in the bottom chamber. Reagent control reaction mixtures included cells incubated with IIID-9 or the isotype control IgG only under identical culture conditions (eighth and ninth bars, respectively). (D) Specific inhibition of Bm-MIF-induced migration of human monocytes/macrophages by anti-Bm-MIF polyclonal sera. The migration induced by 1 ng of Bm-MIF per ml in the bottom chamber of the apparatus is shown by the first bar and by the dashed line. Anti-Bm-MIF serum or preimmunization control serum (Ctrl Ab) was preincubated with 1 ng of Bm-MIF per ml for 1 h at 25°C prior to placement of the mixture in the bottom chamber. Reagent control reaction mixtures included cells incubated with anti-Bm-MIF or preimmune serum only under identical culture conditions (eighth and ninth bars, respectively).