Mitogenic Factor and Migration Inhibitory Factor in Supernatants of Serum-Free Human Lymphocyte Cultures Stimulated with Concanavalin A

Incubation of human peripheral blood lymphocytes with Concanavalin A (Con A) in serum-free media results in the generation of soluble active substances which induce DNA synthesis in autologous and allogeneic lymphocytes (mitogenic factor – MF) and inhibit macrophage migration (migration inhibitory factor – MIF). Both substances retain their activity after removal of Con A by binding of Con A to highly polymerized dextrans. Using Sephadex column chromatography, MF and MIF show different elution profiles and can be completely separated from each other. The heterogeneity of MF and the similarity of MIF in molecular weight induced in Con A and PPD stimulated cultures is discussed.