title: Concanavalin A-induced macrophage aggregating factor.
abstract: The production of the lymphokine activity macrophage aggregating factor (MAgF) by Concanavalin A (Con A)-pulsed guinea-pig spleen cells has been investigated. The following observations have been made: (1) MAgF can be assayed quantitatively by measuring the light absorbance of peritoneal exudate cells (PEC) using a spectrophotometer, rather than the previously used Born platelet aggregometer; (2) both Con A and antigen-induced MAgF elute from Sephadex G-200 over the 30,000-70,000 m wt range; (3) Con A-pulsed spleen cells generate supernatants which can be assayed directly for MAgF. Inhibitor studies with alpha-methyl-D-mannoside show that the observed PEC aggregation is due to MAgF and not to residual Con A, which also aggregates these cells.
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000276:immunology; D002850:Chromatography, Gel; D003208:Concanavalin A / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D008222:Lymphokines / Q000032:analysis / Q000096:biosynthesis*; D008262:Macrophage Activation; D008297:Male
chemical_list: D001500:BCG Vaccine; D008222:Lymphokines; D003208:Concanavalin A