INHIBIN AND ACTIVIN MODULATE HUMAN MONOCYTE CHEMOTAXIS AND HUMAN LYMPHOCYTE INTERFERON-GAMMA PRODUCTION

Inhibin and activin are referred to as gonadal glycoprotein hormones whose function is the control of FSH release from the pituitary gland. However, several observations indicate that inhibin and activin are produced in various organs and serve multiple functions. Because bone marrow and spleen produce inhibin and activin, our aim was to evaluate their possible effect on cell-mediated immune function. For this reason we studied 1) monocyte chemotaxis, 2) lymphocyte interferon-gamma production, 3) phytohemagglutinin-induced lymphocyte proliferation, and 4) nonmajor histocompatibility complex-restricted and lymphokine-activated lymphocyte cytotoxicity. All studies were performed on human peripheral blood cells in the absence or presence of various doses of inhibin, activin, or inhibin plus activin. A significant dose-related increase in monocyte chemotaxis was induced by inhibin. Activin increased the migrational activity of monocytes, but via random, not directed, migration. Inhibin significantly decreased interferon-gamma production, and its effect was reversed by activin. Inhibin and/or activin had no significant effect on either phytohemagglutinin-induced lymphocyte proliferation or lymphocyte cytotoxic capability. The present demonstration that inhibin and activin may affect some immune parameters suggests a possible involvement of these hormones in regulating cell-mediated immune function.