Activated Integrins Identify Functional Antigen-Specific CD8 + T Cells Within Minutes After Antigen Stimulation

Proc Natl Acad Sci U S A. 2018 Jun 12;115(24):E5536-E5545. doi: 10.1073/pnas.1720714115. Epub 2018 May 29.


Immediate β2-integrin activation upon T cell receptor stimulation is critical for effective interaction between T cells and their targets and may therefore be used for the rapid identification and isolation of functional T cells. We present a simple and sensitive flow cytometry-based assay to assess antigen-specific T cells using fluorescent intercellular adhesion molecule (ICAM)-1 multimers that specifically bind to activated β2-integrins. The method is compatible with surface and intracellular staining; it is applicable for monitoring of a broad range of virus-, tumor-, and vaccine-specific CD8+ T cells, and for isolating viable antigen-reacting cells. ICAM-1 binding correlates with peptide-MHC multimer binding but, notably, it identifies the fraction of antigen-specific CD8+ T cells with immediate and high functional capability (i.e., expressing high levels of cytotoxic markers and cytokines). Compared with the currently available methods, staining of activated β2-integrins presents the unique advantage of requiring activation times of only several minutes, therefore delivering functional information nearly reflecting the in vivo situation. Hence, the ICAM-1 assay is most suitable for rapid and precise monitoring of functional antigen-specific T cell responses, including for patient samples in a variety of clinical settings, as well as for the isolation of functional T cells for adoptive cell-transfer immunotherapies.

Keywords: ICAM-1 multimers; antigen-specific T cells; flow cytometry cell sorting; integrins; monitoring.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adoptive Transfer / methods
  • Adult
  • Antigens / immunology*
  • CD18 Antigens / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Humans
  • Immunotherapy, Adoptive / methods
  • Intercellular Adhesion Molecule-1 / immunology
  • Lymphocyte Activation / immunology
  • Receptors, Antigen, T-Cell / immunology
  • Young Adult


  • Antigens
  • CD18 Antigens
  • Receptors, Antigen, T-Cell
  • Intercellular Adhesion Molecule-1