Direct measurement of peptide-specific CD8+ T cells using HLA-A2:Ig dimer for monitoring the in vivo immune response to a HER2/neu vaccine in breast and prostate cancer patients.
HER2/neu is a proto-oncogene and a member of the epidermal growth factor receptor family of proteins that is overexpressed in numerous types of human cancer. We are currently conducting clinical trials with the HER2/neu E75 peptide vaccine in breast and prostate cancer patients. We have evaluated the use of HLA-A2 dimer molecule for the immunological monitoring of cancer patients receiving the E75 peptide vaccine. Peripheral blood samples from patients receiving the vaccine were stained with HLA-A2 dimers containing the vaccine peptide E75 or control peptides and analyzed by flow cytometry. We compared the HLA-A2 dimer assay to standard methods of immunologic monitoring (IFN-gamma release, lymphocyte proliferation, and cytotoxicity). The HLA-A2 dimer assay was also compared with the HLA-A2 tetramer assay. E75 peptide-specific CD8 T cells were detected directly in the peripheral blood of patients by staining with E75-HLA-A2 dimers and CD8 antibodies. T cell cultures generated by repeated stimulations using E75 peptide-pulsed dendritic cells showed increased staining with E75-peptide loaded HLA-A2 dimers. Simultaneously analysis by the dimer assay and standard immunologic assays demonstrated that the dimer-staining assay correlated well with these methods of immunologic monitoring. A direct comparison using E75-specific HLA-A2 tetramers and HLA-A2 dimers for the detection of E75-specific CD8 T cells in peripheral blood showed comparable results with the two assays. Our findings indicate that the HLA-A2 dimer is a powerful new tool for directly quantifying and monitoring immune responses of antigen-specific T cells in peptide vaccine clinical trials.
Woll
Michael M
MM
Department of General Surgery, Walter Reed Army Medical Center, 6900 Georgia Avenue NW, Washington, DC 20307-5001, USA.
Fisher
Christine M
CM
Ryan
Gayle B
GB
Gurney
Jennifer M
JM
Storrer
Catherine E
CE
Ioannides
Constantin G
CG
Shriver
Craig D
CD
Moul
Judd W
JW
McLeod
David G
DG
Ponniah
Sathibalan
S
Peoples
George E
GE
D000917:Antibody Formation; D000951:Antigens, Neoplasm / Q000276:immunology; D001943:Breast Neoplasms / Q000628:therapy*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D019496:Cancer Vaccines; D019281:Dimerization; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D015789:HLA-A2 Antigen; D006801:Humans; D007136:Immunoglobulins; D008297:Male; D011471:Prostatic Neoplasms / Q000628:therapy*; D000090063:Proto-Oncogene Mas; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology
D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D015789:HLA-A2 Antigen; D007136:Immunoglobulins; D000090063:Proto-Oncogene Mas; D018719:Erb-b2 Receptor Tyrosine Kinases; C000715470:MAS1 protein, human