Cytotoxic T cells

J Invest Dermatol. 2006 Jan;126(1):32-41. doi: 10.1038/sj.jid.5700001.

Abstract

The immune system is a complex arrangement of cells and molecules that preserve the integrity of the organism by elimination of all elements judged dangerous. Within the immune system, a humoral and a cellular as well as an innate and an adaptive arm can be differentiated. The key players of adaptive cellular immune responses are T lymphocytes in general and, for the effector function, cytotoxic T lymphocytes (CTLs) in particular. T lymphocytes arise in the bone marrow and migrate to the thymus for maturation. During this process, T cells somatically rearrange gene segments, eventually leading to the expression of a unique antigen-binding molecule, the T-cell receptor (TCR). This receptor allows them to monitor all cells of the body, ready to destroy any cell posing a threat to the organism. Cytotoxicity is exerted directly through the Fas or perforin pathway and/or indirectly by the release of cytokines. Obviously, the activity of such a potent cell is tightly regulated. Indeed, a predominance of stimulatory over inhibitory signals is required for effective immune responses to pathogens, and a predominance of inhibitory over stimulatory signals is required for maintenance of self-tolerance. Still, several situations occur in which an inappropriate CTL response leads to either autoimmune disease or persistence of pathogens.

Publication types

  • Review

MeSH terms

  • Autoimmune Diseases / immunology
  • Biomarkers / analysis
  • Cytotoxicity, Immunologic*
  • Humans
  • Hypersensitivity, Delayed / immunology
  • Immunologic Surveillance
  • Lymphocyte Activation
  • Neoplasms / immunology
  • Receptors, Antigen, T-Cell / immunology*
  • T-Lymphocytes, Cytotoxic / immunology*

Substances

  • Biomarkers
  • Receptors, Antigen, T-Cell