CONSTITUTIVE AND INDUCIBLE GRANULOCYTE-MACROPHAGE FUNCTIONS IN MOUSE, RAT, AND HUMAN MYELOID LEUKEMIA-DERIVED CONTINUOUS TISSUE-CULTURE LINES

Abstract

Fourteen continous tissue culture cell lines derived from mouse, rat or human granulocyte-macrophage cancers were studied for expression of spontaneous and inducible markers of differentiated cells. Five cell lines (2 mouse, 2 rat and 1 human) synthesized myeloperoxidase spontaneously, and a 5th mouse line showed biochemically inducible enzyme. Twelve lines (6 mouse, 3 rat and 3 human) produced lysozyme (muramidase), and all had detectable .beta.-glucuronidase. Superoxide generation was detected in 1 mouse, and 3 human cell lines following stimulation with phorbol myristate acetate. Maturation to differentiated polymorphonuclear leukocyte or macrophage morphology was induced in 3 cell lines (2 mouse and 1 human) following culture in diffusion chambers in total-body-irradiated rats. In vitro morphological differentiation was inducible in 1 (mouse) cell line exposed to casein, thioglycolate or plasma from irradiated rats or mice. These findings indicate that mammalian cell lines derived from granulocyte-macrophage cancers stably express several combinations of differentiation markers. The patterns of expression of these markers did not always correlate with the morphological stage of differentiation.