CHEMICAL MEDIATION OF DELAYED-HYPERSENSITIVITY SKIN REACTIONS .2. CHARACTERIZATION OF A MACROPHAGE-CHEMOTACTIC FACTOR FROM BOVINE GAMMA-GLOBULIN-INDUCED SKIN REACTIONS IN GUINEA-PIGS

Abstract

Macrophage-chemotactic factors [MCFS] were extracted from delayed hypersensitivity skin lesions induced by bovine .gamma.-globulin in guinea pigs. The most active factor, MCFS-1, was a heat-labile protein with a MW of 150,000 and possessed in vivo and in vitro activity. This factor was homogeneous during polyacrylamide gel electrophoresis. The chemotactic activity was associated exclusively with this band. Its isoelectric point was 6.7-6.9 and it made a single arc in the .beta.-globulin region with rabbit antisera against guinea pig serum on immunoelectrophoresis. This factor seemed to be antigenically different from immunoglobulin[Ig]G by immunodiffusion and immunoadsorption. The chemotactic activity of MCFS-2 was not adsorbed by anti-IgG nor anti-MCFS-1. The chemotactic activity of the euglobulin fraction was partially adsorbed by anti-IgG. At least 3 types of antigenically different chemotactic factors probably exist for macrophages in the extracts of delayed hypersensitivity skin lesions.