Vaccination with irradiated Listeria induces protective T cell immunity

Immunity. 2006 Jul;25(1):143-52. doi: 10.1016/j.immuni.2006.05.013.


We evaluated gamma-irradiated Listeria monocytogenes as a killed bacterial vaccine, testing the hypothesis that irradiation preserves antigenic and adjuvant structures destroyed by traditional heat or chemical inactivation. Irradiated Listeria monocytogenes (LM), unlike heat-killed LM, efficiently activated dendritic cells via Toll-like receptors and induced protective T cell responses in mice. Like live LM, irradiated LM induced Toll-like-receptor-independent T cell priming. Cross-presentation of irradiated listerial antigens to CD8(+) T cells involved TAP- and proteasome-dependent cytosolic antigen processing. These results establish that killed LM can induce protective T cell responses, previously thought to require live infection. gamma-irradiation may be potentially applied to numerous bacterial vaccine candidates, and irradiated bacteria could serve as a vaccine platform for recombinant antigens derived from other pathogens, allergens, or tumors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antigen Presentation / immunology
  • Bacterial Proteins / biosynthesis
  • Cell Differentiation
  • Cells, Cultured
  • Cytosol / immunology
  • Cytosol / metabolism
  • Dendritic Cells / cytology
  • Dendritic Cells / metabolism
  • Listeria monocytogenes / immunology*
  • Listeria monocytogenes / metabolism
  • Listeria monocytogenes / radiation effects*
  • Listeriosis / immunology*
  • Listeriosis / microbiology
  • Listeriosis / pathology
  • Listeriosis / prevention & control*
  • Lymphocyte Activation / immunology
  • Mice
  • Survival Rate
  • T-Lymphocytes / immunology*
  • Toll-Like Receptors / metabolism
  • Vaccination*


  • Bacterial Proteins
  • Toll-Like Receptors