Thioglycollate-elicited mouse peritoneal macrophages are less efficient than resident macrophages in antibody-dependent cell-mediated cytolysis.

Abstract

Peritoneal macrophages (M phi) obtained after i.p. injection of Brewer thioglycollate medium (TG) were substantially less efficient than resident (R) M phi in an assay of antibody-dependent cell-mediated cytolysis (ADCC) in which 51Cr-labeled sheep erythrocytes were used as target cells. The TG-M phi did not display any generalized functional defects, and indeed were "activated" relative to R-M phi by several morphologic, biochemical, and functional criteria. The ADCC deficiency was observed with TG-M phi from four strains of mice, and was not altered by the use of different types of target cells or different sensitizing IgG antibodies. Treatments that significantly enhanced R-M phi ADCC activity, either inhibition of phagocytosis by tosyl lysine chloromethyl ketone or stimulation of M phi enzyme secretion and O2- production, resulted in only a modest enhancement of TG-M phi ADCC. The effect of i.p. TG injection on M phi ADCC activity was not mimicked by in vitro exposure of R-M phi to TG. In vivo experiments demonstrated that agar, a component of TG, was sufficient to elicit M phi that resembled TG-M phi morphologically and functionally. We discuss the possibility that the ADCC deficiency of TG-M phi may be a characteristic of cells involved in the subsidence of an acute inflammatory response.