Lymphokine-mediated activation of human monocytes: neutralization by monoclonal antibody to interferon-gamma.
Purified natural and recombinant human immune interferon (IFN-gamma) were found to activate human monocytes from peripheral blood to exert enhanced cytotoxicity against human colon adenocarcinoma HT-29 cells. A marked monocyte activation was observed at low concentrations (1 and 10 U/ml) of IFN-gamma. Marked monocyte activation was also obtained with two lymphokine preparations, produced in peripheral blood mononuclear cell (PBM) cultures induced with phytohemagglutinin (PHA) or by combined stimulation with PHA and 12-O-tetradecanoylphorbol 13-acetate (TPA). The component responsible for macrophage activation in such lymphokine preparations in the past was considered to be "macrophage-activating factor" (MAF). When monoclonal antibody specifically neutralizing IFN-gamma was added to these lymphokine preparations, all MAF activity disappeared, indicating that IFN-gamma is the sole protein showing MAF activity in these preparations.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D009500:Neutralization Tests
D000911:Antibodies, Monoclonal; D008222:Lymphokines; D007371:Interferon-gamma