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

J Clin Immunol. 2004 Jul;24(4):449-61. doi: 10.1023/B:JOCI.0000029117.10791.98.


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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antibody Formation*
  • Antigens, Neoplasm / immunology
  • Breast Neoplasms / therapy*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cancer Vaccines*
  • Dimerization
  • Drug Monitoring / methods*
  • Female
  • HLA-A2 Antigen*
  • Humans
  • Immunoglobulins
  • Male
  • Prostatic Neoplasms / therapy*
  • Proto-Oncogene Mas
  • Receptor, ErbB-2 / immunology


  • Antigens, Neoplasm
  • Cancer Vaccines
  • HLA-A2 Antigen
  • Immunoglobulins
  • MAS1 protein, human
  • Proto-Oncogene Mas
  • Receptor, ErbB-2