Selective suppression of human B lymphocyte differentiation into IgG-producing cells by soluble Fc gamma receptors

Receptors for the Fc part of IgG were isolated by affinity chromatography from supernatants of unstimulated human lymphocytes or polymorphonuclear neutrophils. When added to cultures stimulated by polyclonal activators, these soluble receptors selectively depressed the maturation of B lymphocytes into IgG-producing cells, whereas the number of IgM-producing cells was either increased or unchanged. The number of IgA-containing cells was not changed. The data support the concept of class-specific control of Ig synthesis by Fc receptors.