In vitro Augmentation of Natural Killer Cell Activity and Production of Interferon‐α/β and ‐γ with Deoxyribonucleic Acid Fraction from Mycobacterium bovis BCG

Abstract

A nucleic acid-rich fraction extracted and purified from BCG (MY-1) augmented natural killer (NK) cell activity of mouse spleen cells in vitro, and produced factor(s) which showed anti-viral activity and rendered normal macrophages cytotoxic towards tumor cells. These cellular responses were induced by the MY-1 digested preliminary with RNase, but not by the MY-1 digested with DNase, indicating that DNA contained in MY-1 was essential for the responses. The function of the factor to activate macrophages was destroyed by treatment with a small amount of antiinterferon (IFN)-.gamma. antiserum or under acidic conditions (pH 2), but not by treatment with anti-IFN-.alpha./.beta. antiserum, while the anti-viral activity was destroyed almost completely by treatment with anti-IFN-.alpha./.beta. antiserum. It appears that DNA from BCG stimulated mouse spleen cells in vitro, resulting in augmentation of NK activity and production of IFN-.alpha./.beta. and -.gamma.