Analysis of CD127 and KLRG1 expression on hepatitis C virus-specific CD8+ T cells reveals the existence of different memory T-cell subsets in the peripheral blood and liver

J Virol. 2007 Jan;81(2):945-53. doi: 10.1128/JVI.01354-06. Epub 2006 Nov 1.

Abstract

The differentiation and functional status of virus-specific CD8+ T cells is significantly influenced by specific and ongoing antigen recognition. Importantly, the expression profiles of the interleukin-7 receptor alpha chain (CD127) and the killer cell lectin-like receptor G1 (KLRG1) have been shown to be differentially influenced by repetitive T-cell receptor interactions. Indeed, antigen-specific CD8+ T cells targeting persistent viruses (e.g., human immunodeficiency virus and Epstein-Barr virus) have been shown to have low CD127 and high KLRG1 expressions, while CD8+ T cells targeting resolved viral antigens (e.g., FLU) typically display high CD127 and low KLRG1 expressions. Here, we analyzed the surface phenotype and function of hepatitis C virus (HCV)-specific CD8+ T cells. Surprisingly, despite viral persistence, we found that a large fraction of peripheral HCV-specific CD8+ T cells were CD127+ and KLRG1- and had good proliferative capacities, thus resembling memory cells that usually develop following acute resolving infection. Intrahepatic virus-specific CD8+ T cells displayed significantly reduced levels of CD127 expression but similar levels of KLRG1 expression compared to the peripheral blood. These results extend previous studies that demonstrated central memory (CCR7+) and early-differentiated phenotypes of HCV-specific CD8+ T cells and suggest that insufficient stimulation of virus-specific CD8+ T cells by viral antigen may be responsible for this alteration in HCV-specific CD8+ T-cell differentiation during chronic HCV infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Amino Acid Sequence
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Female
  • Hepacivirus / immunology*
  • Hepatitis C / immunology*
  • Hepatitis C / virology
  • Hepatitis C, Chronic / immunology
  • Hepatitis C, Chronic / virology
  • Humans
  • Immunologic Memory*
  • Interleukin-7 Receptor alpha Subunit / metabolism*
  • Lectins, C-Type / metabolism*
  • Liver / cytology
  • Liver / immunology
  • Lymphocyte Activation
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Receptors, Immunologic
  • Trans-Activators / metabolism*

Substances

  • Interleukin-7 Receptor alpha Subunit
  • KLRG1 protein, human
  • Lectins, C-Type
  • Receptors, Immunologic
  • Trans-Activators