Antigen-specific T cell receptor antagonism by antigen-presenting cells treated with the hemolysin of Listeria monocytogenes: a novel type of immune escape

Eur J Immunol. 1997 Jul;27(7):1696-703. doi: 10.1002/eji.1830270716.


We have examined the influence of listeriolysin O (LLO), the hemolysin secreted by the pathogenic bacterium Listeria monocytogenes, on major histocompatibility complex class II-dependent T cell activation. Stimulation of T cells by native antigens but not by peptides is inhibited upon pretreatment of antigen-presenting cells (APC) with LLO. Experiments presented here reveal that this inhibition is not due to a lack in processing of antigen by APC but is the result of an irreversible inactivation of T cells that recognize antigen on LLO-treated APC. Incubation of mixtures of two different T cells where only one antigen was presented on LLO-treated APC suggested that T cell inactivation is antigen specific. The inactivation was dominant and could be observed even in the presence of amounts of synthetic peptides that normally lead to T cell responses. This condition is reminiscent of the T cell inhibition observed when antagonistic and stimulatory peptides are added to APC at the same time. Our results thus reveal a novel type of interference by pathogens with antigen presentation and T cell stimulation that could give the pathogen a decisive advantage in dissemination and disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen Presentation / drug effects
  • Antigen-Presenting Cells / drug effects
  • Antigen-Presenting Cells / immunology*
  • Antigen-Presenting Cells / metabolism*
  • Bacterial Proteins / pharmacology
  • Bacterial Toxins*
  • Cell Line
  • Epitopes / drug effects*
  • Female
  • Heat-Shock Proteins / pharmacology*
  • Hemolysin Proteins / pharmacology*
  • Histocompatibility Antigens Class II / drug effects
  • Hybridomas
  • Listeria monocytogenes / immunology*
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Receptors, Antigen, T-Cell / antagonists & inhibitors*
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / metabolism
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Time Factors


  • Bacterial Proteins
  • Bacterial Toxins
  • Epitopes
  • Heat-Shock Proteins
  • Hemolysin Proteins
  • Histocompatibility Antigens Class II
  • Receptors, Antigen, T-Cell
  • hlyA protein, Listeria monocytogenes