CD8+ T cell exhaustion during persistent viral infection is regulated independently of the virus-specific T cell receptor

Immunol Invest. 2013;42(3):204-20. doi: 10.3109/08820139.2012.751397. Epub 2013 Mar 5.

Abstract

During chronic viral infections, responses by virus-specific CD8(+) T cells become marginalized by the acquisition of functional defects and reduced cell numbers in a process defined as T cell exhaustion. Similarly, T cell tolerance to self-antigen is also characterized by impaired effector function and eventual deletion of self-reactive T cells. Induction of both tolerance and exhaustion involve many shared inhibitory mechanisms, thus similar therapeutic approaches have proven effective in these distinct environments. We previously demonstrated that tolerant self-reactive CD8(+) T cells expressing dual-T cell receptors (i.e., dual-TCR) could be rescued by immunization through a second TCR specific for a foreign antigen. These data revealed that T cell tolerance was regulated at the level of the self-reactive TCR. Here, dual-TCR CD8(+) T cells were used to examine if exhaustion during persistent viral infection could be rescued by an analogous strategy of immunization through a second TCR not involved in recognition of virus. In direct contrast to the rescue achievable in tolerant CD8(+) T cells, exhausted T cells were equally impaired through both TCR. These findings suggest that exhaustion is maintained by defects downstream of the virus-specific TCR, and establish that exhaustion and tolerance are distinctly regulated states of T cell dysfunction.

Publication types

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

MeSH terms

  • Animals
  • Antigens, Viral / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / transplantation
  • CD8-Positive T-Lymphocytes / virology
  • Chronic Disease
  • Humans
  • Immunization
  • Lymphocyte Activation
  • Lymphocytic Choriomeningitis / immunology*
  • Lymphocytic Choriomeningitis / physiopathology*
  • Lymphocytic Choriomeningitis / virology
  • Lymphocytic choriomeningitis virus / immunology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / metabolism*

Substances

  • Antigens, Viral
  • Receptors, Antigen, T-Cell