Apoptosis

, Volume 10, Issue 4, pp 707–715

No life without death—apoptosis as prerequisite for T cell activation

  • F. Winau
  • G. Hegasy
  • S. H. E. Kaufmann
  • U. E. Schaible
Article

DOI: 10.1007/s10495-005-2940-6

Cite this article as:
Winau, F., Hegasy, G., Kaufmann, S.H.E. et al. Apoptosis (2005) 10: 707. doi:10.1007/s10495-005-2940-6

The orchestrated death of infected cells is key to our understanding of CD8 T cell activation against pathogens. Most intracellular bacteria including Mycobacterium tuberculosis, the etiologic agent of tuberculosis, remain enclosed in phagosomes of infected macrophages. CD8 T cells play a critical role in defense of infection and recognize antigens originating from the cytosol presented by MHC-I molecules. Since mycobacteria do not gain access to the cytosolic MHC-I presentation pathway, the fundamental question as to how CD8 T cells encounter mycobacterial antigens remains to be solved. In this review, we focus on solutions for this enigma and describe the detour pathway of T cell activation. Mycobacteria induce cell death of infected macrophages which thereby leave a last message by releasing apoptotic vesicles. Subsequently, these antigen-containing entities are engulfed by dendritic cells which process the mycobacterial cargo for efficient antigen presentation and CD8 T cell activation. Since the dying infected cell is the origin of a protective T cell response destined to preserve life and individuality, the detour pathway represents an altruistic principle at a cellular level which corresponds to the macroscopic world where death is the precondition to perpetuate the living.

Keywords

apoptosis CD8 T cells cross-priming tuberculosis 

Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  • F. Winau
    • 1
  • G. Hegasy
    • 1
  • S. H. E. Kaufmann
    • 1
  • U. E. Schaible
    • 1
  1. 1.Department of ImmunologyMax-Planck-Institute for Infection BiologyBerlinGermany

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