Early myeloid cells are high producers of nitric oxide upon CD40 plus IFN-gamma stimulation through a mechanism dependent on endogenous TNF-alpha and IL-1alpha

Eur J Immunol. 2000 May;30(5):1263-71. doi: 10.1002/(SICI)1521-4141(200005)30:5<1263::AID-IMMU1263>3.0.CO;2-5.


Bone marrow contains nonadherent low-density wheat germ agglutinin-positive (Fr3-WGA(+)) cells that release large amounts of NO and show natural suppressor activity if stimulated with activated T cells. We have assessed the involvement of CD40-derived signals in NO production and their cytokine requirements. Production of NO by Fr3-WGA(+) cells in co-culture with activated T cells is inhibited by a competing CD40 soluble fusion protein. Fr3-WGA(+) cells express the inducible NO synthase (iNOS) and release NO following CD40 plus IFN-gamma activation. Production of NO through CD40 is strictly dependent on endogenous TNF-alpha and / or IL-1alpha, since it is inhibited by neutralizing these cytokines or blocking the TNF receptor (p55). Both cytokines are transcribed when Fr3-WGA(+) cells are stimulated by CD40 signaling plus IFN-gamma, although TNF-alpha remains below detection limits in stimulated Fr3-WGA(+) cell cultures. Phenotypic studies combined with data on intracellular iNOS expression and cell sorting indicate that NO-producing cells are CD40, CD31 (ER-MP12), CD11b (Mac-1)low, ER-MP20 (Ly-6C) and Gr-1 (Ly-6G) positive, consistent with myeloid progenitors. The results point to early myeloid cells as an important cell source of NO once triggered by activated T cells through CD40 and IFN-gamma-derived signals, in a mechanism involving the production of TNF-alpha and / or IL-1alpha.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Marrow Cells / immunology*
  • Bone Marrow Cells / metabolism
  • CD40 Antigens / immunology*
  • CD40 Antigens / pharmacology
  • Cell Communication / immunology
  • Coculture Techniques
  • Female
  • Interferon-gamma / immunology*
  • Interferon-gamma / pharmacology
  • Interleukin-1 / immunology
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • Nitric Oxide / biosynthesis
  • Nitric Oxide / immunology*
  • T-Lymphocytes / immunology*
  • Tumor Necrosis Factor-alpha / immunology


  • CD40 Antigens
  • Interleukin-1
  • Tumor Necrosis Factor-alpha
  • Nitric Oxide
  • Interferon-gamma