The CD16-/CD56bright subset of NK cells is resistant to oxidant-induced cell death

J Immunol. 2007 Jul 15;179(2):781-5. doi: 10.4049/jimmunol.179.2.781.


Phagocyte-derived reactive oxygen species ("oxygen radicals") have been ascribed a suppressive role in immunoregulation by inducing dysfunction and apoptotic cell death in lymphocytes. Earlier studies show that human NK cells are exceptionally sensitive to oxygen radical-induced apoptosis and functional inhibition. Two subsets of human CD56(+) NK cells have been identified: the highly cytotoxic CD56(dim) cells which constitute >90% of NK cells in peripheral blood, and the less cytotoxic but efficiently cytokine-producing CD56(bright) cells. In this study, we demonstrate that the CD56(bright) subset of NK cells, in contrast to CD56(dim) cells, remains viable and functionally intact after exposure to phagocyte-derived or exogenously added oxygen radicals. The resistance of CD56(bright) cells to oxidative stress was accompanied by a high capacity of neutralizing exogenous hydrogen peroxide, and by a high cell-surface expression of antioxidative thiols. Our results imply that CD56(bright) NK cells are endowed with an efficient antioxidative defense system that protects them from oxygen radical-induced inactivation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / immunology*
  • CD56 Antigen / immunology
  • CD56 Antigen / metabolism*
  • Humans
  • Hydrogen Peroxide / immunology
  • Hydrogen Peroxide / toxicity
  • Interferon-gamma / immunology
  • Killer Cells, Natural / drug effects
  • Killer Cells, Natural / immunology*
  • Lymphocyte Subsets / drug effects
  • Lymphocyte Subsets / immunology*
  • Oxidants / toxicity
  • Reactive Oxygen Species / immunology*
  • Reactive Oxygen Species / toxicity
  • Receptors, IgG / immunology
  • Receptors, IgG / metabolism*


  • CD56 Antigen
  • Oxidants
  • Reactive Oxygen Species
  • Receptors, IgG
  • Interferon-gamma
  • Hydrogen Peroxide