Cytotoxic T lymphocytes: all roads lead to death

Nat Rev Immunol. 2002 Jun;2(6):401-9. doi: 10.1038/nri819.


Cytotoxic T lymphocytes (CTLs) provide potent defences against virus infection and intracellular pathogens. However, CTLs have a dark side--their lytic machinery can be directed against self-tissues in autoimmune disorders, transplanted cells during graft rejection and host tissues to cause graft-versus-host disease, which is one of the most serious diseases related to CTL function. Although this duplicitous behaviour might seem contradictory, both beneficial and detrimental effects are the result of the same effector proteins. So, an understanding of the mechanisms that are used by CTLs to destroy targets and a knowledge of pathogen immune-evasion strategies will provide vital information for the design of new therapies.

Publication types

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

MeSH terms

  • Animals
  • Autoimmunity
  • Cell Death / immunology
  • Cytotoxicity, Immunologic
  • Graft Rejection
  • Graft vs Host Disease / immunology
  • Granzymes
  • Humans
  • Killer Cells, Natural / immunology
  • Mice
  • Models, Immunological
  • Rats
  • Serine Endopeptidases / immunology
  • T-Lymphocytes, Cytotoxic / enzymology
  • T-Lymphocytes, Cytotoxic / immunology*
  • Viruses / immunology


  • GZMB protein, human
  • Granzymes
  • Gzmb protein, mouse
  • Gzmb protein, rat
  • Serine Endopeptidases