The chemical mediation of delayed hypersensitivity skin reactions. I. Purification of a macrophage-chemotactic factor from bovien gamma-globulin-induced skin reactions in guinea pigs.

A macrophage-chemotactic factor (MCFS) was extracted in the pseudoglobulin fraction from delayed hypersensitivity skin lesions induced by bovine gamma-globulin in guinea pigs. Its chemotactic activity was estimated by a modification of Boyden's method using Nuclepore filter. After chromatography of the protein fraction using Sephadex G-50 and DEAE-cellulose, in that order, two chemotactic fractions were obtained. The chemotactic factor with stronger activity (MCFS-1) was further highly purified (488-fold) by chromatography on CM-Sephadex. This factor migrated in a single band on acrylamide disc gel electrophoresis and was found to be a protein that was free of nucleic acid. Gel filtration showed that its molecular weight was similar to that of IgG. Its chemotactic activity was heat labile. Intradermal injection of this factor into normal guinea pigs induced a pronounced mononuclear cell emigration from venules. These findings are pertinent to understanding macrophage reaction in the delayed hypersensitivity reactions. Am J Pathol 87:359-374, 1977).