Site of action of cortisol in cellular immunity.

Cell-mediated immunity reactions involve antigen-sensitive lymphocytes and monocytemacrophages. These reactions are inhibited by cortisol. To elucidate the site of inhibition by cortisol, we used an in vitro test of cellular immunity, the macrophage aggregation factor (MAF) assay. 10-3 M cortisol did not prevent sensitized lymphocytes from manufacturing and releasing MAF, but did prevent nonimmune macrophages from responding to MAF. The location of inhibition of cortisol in cell-mediated immune responses is between the lymphokine and the monocyte-macrophage.