Activation of human B lymphocytes. IX. Modulation of antibody production by products of activated macrophages.
Human monocytes, after in vitro activation by mixed lymphocyte culture (MLC) supernatants produce a monokine (MK) that enhances the plaque-forming cell (PFC) response of pokeweed mitogen (PWM)-stimulated human B lymphocytes. Technical conditions and kinetics of MK production were established. Irradiation of monocytes (5000 rads) does not abolish MK production but heat-killed cells are unable to release the factor. Highly T cell-depleted monocyte populations still produced the PFC-enhancing factor. The same MK has an inconsistent enhancing effect on the PFC responses of lipopolysaccharide (LPS) and nocardia water-soluble mitogen (NWSM)-stimulated B cells. Other macrophage activators such as LPS, phytohemagglutinin (PHA), and latex particles failed to induce consistently the liberation of the PFC-enhancing MK. The target cell for the MK activity on PWM-stimulated B cells appears to be the B lymphocyte itself. These studies demonstrate that soluble monocyte products can have substantial modulatory effects on human B cell function.
D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D006462:Hemolytic Plaque Technique; D006801:Humans; D007700:Kinetics; D037102:Lectins / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008222:Lymphokines / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology*; D009000:Monocytes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D037102:Lectins; D008070:Lipopolysaccharides; D008222:Lymphokines