Optimized combinatorial pMHC class II multimer labeling for precision immune monitoring of tumor-specific CD4 T cells in patients

J Immunother Cancer. 2020 May;8(1):e000435. doi: 10.1136/jitc-2019-000435.


Background: With immunotherapy gaining increasing approval for treatment of different tumor types, scientists rely on cutting edge methods for the monitoring of immune responses and biomarker development in patients. Due to the lack of tools to efficiently detect rare circulating human tumor-specific CD4 T cells, their characterization in patients still remains very limited.

Methods: We have used combinatorial staining strategies with peptide major histocompatibility complex class II (pMHCII) multimer constructs of different alleles to establish an optimized staining procedure for in vitro and direct ex-vivo visualization of tumor-specific CD4 T cells, in patient samples. Furthermore, we have generated reversible multimers to achieve optimal cell staining and yet disassemble prior to in vitro cell expansion, thus preventing activation induced cell death.

Results: We observed a vastly improved detection of tumor-specific, viral-specific and bacterial-specific cells with our optimization methods compared with the non-optimized staining procedure. By increasing the variety of fluorochromes used to label the pMHCII multimers, we were also able to increase the parallel detection of different specificities within one sample, including antigen-specific CD8 T cells. A decrease in cell viability was observed when using the full optimization method, but this was mitigated by the removal of neuraminidase and the use of reversible multimers.

Conclusion: This new optimized staining procedure represents an advance toward better detection and analysis of antigen-specific CD4 T cells. It should facilitate state-of-the art precision monitoring of tumor-specific CD4 T cells and contribute to accelerate the use and the targeting of these cells in cancer immunotherapy.

Keywords: immunology; oncology.

Publication types

  • Clinical Trial, Phase I
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Cancer Vaccines / administration & dosage
  • Epitopes, T-Lymphocyte / immunology
  • Female
  • Flow Cytometry / methods
  • Histocompatibility Antigens Class II / immunology
  • Histocompatibility Antigens Class II / metabolism*
  • Humans
  • Immunogenicity, Vaccine
  • Male
  • Melanoma / diagnosis*
  • Melanoma / immunology
  • Melanoma / therapy
  • Middle Aged
  • Molecular Imaging / methods
  • Monitoring, Immunologic / methods*
  • Protein Multimerization
  • Skin Neoplasms / diagnosis*
  • Skin Neoplasms / immunology
  • Skin Neoplasms / therapy
  • Staining and Labeling / methods
  • Vaccines, Subunit / administration & dosage


  • Cancer Vaccines
  • Epitopes, T-Lymphocyte
  • Histocompatibility Antigens Class II
  • Vaccines, Subunit