TY - JOUR
T1 - Differential CTLs specific for prostate-specific antigen in healthy donors and patients with prostate cancer
AU - Elkord, Eyad
AU - Williams, Paul E.
AU - Kynaston, Howard
AU - Rowbottom, Anthony W.
PY - 2005/10
Y1 - 2005/10
N2 - Induction of CTL responses specific for prostate-specific antigen (PSA)-derived peptides in healthy individuals and patients with prostate cancer (PC) was investigated. Eight PSA-derived peptides that have the potential to bind HLA-A2 molecules were examined. Peripheral blood lymphocytes isolated from HLA-A2-positive volunteers were expanded using autologous mature, PSA-derived peptide-pulsed dendritic cells. The expansion of IFN-γ-secreting CD8+ T cells specific for three of the eight PSA-derived peptides (PSA-2108-117, PSA-4141-150 and PSA-6146-154) was detected in healthy individuals, but not in patients with PC. Using HLA-A2/peptide tetramers, the PSA-specific CD8+ T cells were detectable at low frequency both in healthy individuals and patients with PC. Using flow cytometric cytotoxicity assays, the expanded effectors from healthy individuals were able to kill the PSA-expressing epithelial cell line LNCaP and the peptide-pulsed T2 cells in a MHC class I-restricted manner without involving NK activity. However, such killing by effectors expanded from prostatectomized patients involved a complete or a significant NK activity. Specific recognition of PSA-derived peptides in healthy individuals may occur by an adaptive CTL immune response, while such recognition in PC patients may additionally or alternatively be mediated by an innate NK immune response. In conclusion, our work indicates that the PSA-specific CD8+ T cells exist in both healthy individuals and PC patients, but they have impaired function in patients as they failed to release IFN-γ and to kill targets without involving NK activity.
AB - Induction of CTL responses specific for prostate-specific antigen (PSA)-derived peptides in healthy individuals and patients with prostate cancer (PC) was investigated. Eight PSA-derived peptides that have the potential to bind HLA-A2 molecules were examined. Peripheral blood lymphocytes isolated from HLA-A2-positive volunteers were expanded using autologous mature, PSA-derived peptide-pulsed dendritic cells. The expansion of IFN-γ-secreting CD8+ T cells specific for three of the eight PSA-derived peptides (PSA-2108-117, PSA-4141-150 and PSA-6146-154) was detected in healthy individuals, but not in patients with PC. Using HLA-A2/peptide tetramers, the PSA-specific CD8+ T cells were detectable at low frequency both in healthy individuals and patients with PC. Using flow cytometric cytotoxicity assays, the expanded effectors from healthy individuals were able to kill the PSA-expressing epithelial cell line LNCaP and the peptide-pulsed T2 cells in a MHC class I-restricted manner without involving NK activity. However, such killing by effectors expanded from prostatectomized patients involved a complete or a significant NK activity. Specific recognition of PSA-derived peptides in healthy individuals may occur by an adaptive CTL immune response, while such recognition in PC patients may additionally or alternatively be mediated by an innate NK immune response. In conclusion, our work indicates that the PSA-specific CD8+ T cells exist in both healthy individuals and PC patients, but they have impaired function in patients as they failed to release IFN-γ and to kill targets without involving NK activity.
KW - Cytotoxic T lymphocytes
KW - Dendritic cells
KW - NK activity
KW - Prostate cancer
KW - Prostate-specific antigen
UR - http://www.scopus.com/inward/record.url?scp=27144517441&partnerID=8YFLogxK
U2 - 10.1093/intimm/dxh309
DO - 10.1093/intimm/dxh309
M3 - Article
C2 - 16141246
AN - SCOPUS:27144517441
SN - 0953-8178
VL - 17
SP - 1315
EP - 1325
JO - International Immunology
JF - International Immunology
IS - 10
ER -