Gamma interferon expression in CD8(+) T cells is a marker for circulating cytotoxic T lymphocytes that recognize an HLA A2-restricted epitope of human cytomegalovirus phosphoprotein pp65

Clin Diagn Lab Immunol. 2001 May;8(3):628-31. doi: 10.1128/CDLI.8.3.628-631.2001.


Antigen-specific CD8(+) T cells with cytotoxic activity are often critical in immune responses to infectious pathogens. To determine whether gamma interferon (IFN-gamma) expression is a surrogate marker for cytotoxic T lymphocytes (CTL), human cytomegalovirus-specific CTL responses were correlated with CD8(+) T-cell IFN-gamma expression determined by cytokine flow cytometry. A strong positive correlation was observed between specific lysis of peptide-pulsed targets in a (51)Cr release assay and frequencies of peptide-activated CD8(+) T cells expressing IFN-gamma at 6 h (r(2) = 0.72) or 7 days (r(2) = 0.91). Enumeration of responding cells expressing perforin, another marker associated with CTL, did not improve this correlation. These results demonstrate that IFN-gamma expression can be a functional surrogate for identification of CTL precursor cells.

MeSH terms

  • Antigen Presentation
  • Antigens, Viral / immunology*
  • Biomarkers
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytomegalovirus / immunology*
  • Cytotoxicity, Immunologic
  • HLA-A2 Antigen / immunology
  • Humans
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / immunology*
  • Phosphoproteins / immunology


  • Antigens, Viral
  • Biomarkers
  • HLA-A2 Antigen
  • Phosphoproteins
  • Interferon-gamma