Natural killer cells: a mystery no more

Scand J Immunol. 2002 Mar;55(3):229-32. doi: 10.1046/j.1365-3083.2002.01055.x.


Recent years have witnessed remarkable progress in our understanding of the molecular mechanism regulating natural killer (NK) cell function. NK cells can sense whether cells have lost the surface expression of major histocompatibility complex (MHC)-class I molecules. The discovery of MHC-class I-specific inhibitory receptors clarified the basis of this discrimination and elucidated the nature of the 'off' signal. However, the receptors responsible for the 'on' signal in the process of natural cytotoxicity remained mysterious until recently. Here, we describe the identification and characterization of such receptors and discuss the emerging implications of these findings in different diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Allergy and Immunology
  • Animals
  • Awards and Prizes
  • Cytotoxicity, Immunologic
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Immunity, Innate
  • Killer Cells, Natural / immunology*
  • Lymphoproliferative Disorders / genetics
  • Lymphoproliferative Disorders / immunology
  • Neoplasms / immunology
  • Receptors, Immunologic / metabolism
  • Sweden


  • Histocompatibility Antigens Class I
  • Receptors, Immunologic