Different influence of macrophage migration inhibitory factor (MIF) in signal transduction pathway of various T cell subsets

It has been shown that macrophage migration inhibitory factor (MIF) modulat es nor only macrophage functions, bur also T cell functions. However, detai led analysis of the MIF function on responses of various T cell subpopulati ons remained to be elucidated. In this report, using a neutralizing anti-MI F monoclonal antibody (mAb) we examined MIF functions on various T cell lin eages. It was shown that anti-MIF mAb inhibited antigen-specific responses of both IFN-gamma producing and IL-4 producing T cells. The inhibition appe ared to be related to blockade of the signal pathway via T cell receptor (T CR) but not that via IL-2 receptor (IL-2R). However, the anti-MIF mAb showe d no inhibitory effect on NK-T cell responses stimulated through TCR. These results suggest that MIF is involved in the signal pathway via TCR in main stream T cells but not in NK-T cells.