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.
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.
Ghanekar
S A
SA
BD Biosciences, Immunocytometry Systems, San Jose, California 95131, USA. smita_ghanekar@bdis.com
Nomura
L E
LE
Suni
M A
MA
Picker
L J
LJ
Maecker
H T
HT
Maino
V C
VC
D017951:Antigen Presentation; D000956:Antigens, Viral / Q000276:immunology*; D015415:Biomarkers; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003587:Cytomegalovirus / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D015789:HLA-A2 Antigen / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D010750:Phosphoproteins / Q000276:immunology
D000956:Antigens, Viral; D015415:Biomarkers; D015789:HLA-A2 Antigen; D010750:Phosphoproteins; D007371:Interferon-gamma