Biological response modifier having cell differentiation-induction

Abstract

There is provided a proteinaceous biological response modifier having the following properties: (a) molecular weight: 35,000 to 65,000; (b) isoelectric point: 5.0 to 6.1; (c) physiological action on human leukemia cells: to induce human leukemia to differentiate into macrophage-like cells; (d) physiological action on myeloid leukemia cells from mice: to induce myeloid leukemia cells from mice to differentiate into macrophage-like cells; (e) affinity to Concanavalin A Sepharose: not adsorbed; (f) affinity to Blue Sepharose Resin: not adsorbed; (g) pH-stability and thermostability: substantially not inactivated at pH 2 to 10, at 2.degree. C. for 6 hours; not inactivated at 56.degree. C. for 60 minutes; but inactivated by 30% at 70.degree. C. for 60 minutes; (h) sensitivity to enzymes: not inactivated by deoxyribonuclease; not inactivated by glycosidase; and inactivated by protease; (i) flow cytometry analysis: to concentrate cell division cycle of human leukemia cells to G.sub.0 /G.sub.1 phase. There is also provided a process for the production of the proteinaceous biological response modifier comprising culturing human leukemia cells in a differentiation medium in the presence of a substance capable of inducing the human leukemia cells to differentiate into macrophage-like cells; separating the macrophage-like cells from the culture medium; activating the macrophage-like cells in a production medium by a mitogen to enhance the production of the proteinaceous biological response modifier; and isolating the proteinaceous biological response modifier from the production medium. The biological response modifier has anti-tumor activity.