Characterization of Migration Inhibitory Factor (MIF) from Guinea Pig Lymphocytes Stimulated with Concanavalin A

A migration inhibitory factor (MIF) obtained from cultures of guinea pig lymphocytes stimulated with the mitogen concanavalin A (MIFCon A) was characterized and compared to MIF produced by stimulation with the o-chlorobenzoylbovine γ globulin antigen (MIFOCB-BGG). MIFCon A behaves like MIFOCB-BGG on acrylamide gel electrophoresis, in its buoyant density on isopycnic centrifugation, and in its susceptibility to neuraminidase and chymotrypsin. On the other hand, MIFCon A showed greater heterogeneity than MIFOCB-BGG when chromatographed on Sephadex G-100, and Con A stimulated the production of more MIF than antigen. The increase in heterogeneity and activity of MIFCon A over MIFOCB-BGG would be expected if Con A affects more cells than antigen. These experiments suggest that the triggering of different kinds of receptors results in the production of similar mediators, probably through a common pathway.