GM-1, a clone of the monoblastic phagocyte U937 that expresses a large respiratory burst capacity upon activation with interferon-γ

G. Garotta, M. Thelen, D. Delia, M. Kamber, M. Baggiolini

Research output: Contribution to journalArticle


The human cell line U937 was cloned and screened for the responsiveness to interferon-γ (INF-γ). The selected subclone, named GM-1, expressed a high density of IFN-γ receptors and showed HLA typing similar to that of the parental line but was devoid of the Y chromosome. GM-1 cells display a promyeloid phenotype as revealed by flow cytometry using a panel of murine antibodies. Following treatment with IFN-γ GM-1 cells differentiated to a more mature monocyte stage and acquired the capacity to mount a respiratory burst. After treatment with differentiation promotors, such as phorbol 12-myristate 13-acetate (PMA), dimethyl sulfoxide (DMSO), and retinoic acid, GM-1 showed a more limited respiratory burst capacity. Superoxide release in IFN-γ-activated cells was stimulated with f-Met-Leu-Phe, C5a, or PMA. The development of the respiratory burst capacity was accompanied with the expression of cytochrome b558, a component of the phagocyte NADPH-oxidase. GM-1 cells are useful for the study of the effects of IFN-γ on the respiratory burst. They are more sensitive and yield a more homogenous response to IFN-γ than U937 cells. The phenotype of GM-1 cells was stable for more than 5 years.

Original languageEnglish
Pages (from-to)294-301
Number of pages8
JournalJournal of Leukocyte Biology
Issue number3
Publication statusPublished - 1991



  • differentiation
  • monocyte
  • promyeloid phenotype

ASJC Scopus subject areas

  • Cell Biology

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