Multiple mechanisms compensate to enhance tumor-protective CD8(+) T cell response in the long-term despite poor CD8(+) T cell priming initially: comparison between an acute versus a chronic intracellular bacterium expressing a model antigen

J Immunol. 2002 Jun 1;168(11):5737-45. doi: 10.4049/jimmunol.168.11.5737.

Abstract

We evaluated CD8(+) T cell responses against the dominant CTL epitope, OVA(257-264), expressed by an acute (Listeria monocytogenes (LM) OVA) vs a chronic pathogen (Mycobacterium bovis bacillus Calmette-Guérin (BCG) OVA) to reveal the influence on CD8(+) T cell memory and consequent protection against a challenge with OVA-expressing tumor cells. Infection with lower doses of both pathogens resulted in stronger bacterial growth but weaker T cell memory indicating that memory correlates with pathogen dose but not with bacterial expansion. The CD8(+) T cell response induced by LM-OVA was helper T cell-independent and was characterized by a rapid effector response followed by a rapid, but massive, attrition. In contrast, BCG-OVA induced a delayed and weak response that was compensated for by a longer effector phase and reduced attrition. This response was partly dependent on CD4(+) T cells. CD8(+) T cell response induced by BCG-OVA, but not LM-OVA, was highly dependent on pathogen persistence to compensate for the weak initial CD8(+) T cell priming. Despite a stronger initial T cell response with LM-OVA, BCG-OVA provided more effective tumor (B16OVA) control at both local and distal sites due to the induction of a persistently activated acquired, and a more potent innate, immunity.

Publication types

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

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytotoxicity, Immunologic*
  • Female
  • Immunologic Memory
  • Listeria monocytogenes / immunology*
  • Listeriosis / immunology
  • Listeriosis / microbiology
  • Mice
  • Mice, Inbred C57BL
  • Mycobacterium bovis / immunology*
  • Neoplasms, Experimental / prevention & control*
  • Ovalbumin / immunology*
  • Peptide Fragments / immunology*
  • Tuberculosis / immunology
  • Tuberculosis / microbiology

Substances

  • Peptide Fragments
  • Ovalbumin