Human antigen-specific CD4⁺ CD25⁺ CD134⁺ CD39⁺ T cells are enriched for regulatory T cells and comprise a substantial proportion of recall responses

Eur J Immunol. 2014 Jun;44(6):1644-61. doi: 10.1002/eji.201344102. Epub 2014 Apr 29.


Human Ag-specific CD4(+) T cells can be detected by their dual expression of CD134 (OX40) and CD25 after a 44 hours stimulation with cognate Ag. We show that surface expression of CD39 on Ag-specific cells consistently identifies a substantial population of CD4(+) CD25(+) CD134(+) CD39(+) T cells that have a Treg-cell-like phenotype and mostly originate from bulk memory CD4(+) CD45RO(+) CD127(low) CD25(high) CD39(+) Treg cells. Viable, Ag-specific CD25(+) CD134(+) CD39(+) T cells could be expanded in vitro as cell lines and clones, and retained high Forkhead Box Protein 3, CTLA-4 and CD39 expression, suppressive activity and Ag specificity. We also utilised this combination of cell surface markers to measure HIV-Gag responses in HIV(+) patients before and after anti-retroviral therapy (ART). Interestingly, we found that the percentage of CD39(-) cells within baseline CD4(+) T-cell responses to HIV-Gag was negatively correlated with HIV viral load pre-ART and positively correlated with CD4(+) T-cell recovery over 96 weeks of ART. Collectively, our data show that Ag-specific CD4(+) CD25(+) CD134(+) CD39(+) T cells are highly enriched for Treg cells, form a large component of recall responses and maintain a Treg-cell-like phenotype upon in vitro expansion. Identification and isolation of these cells enables the role of Treg cells in memory responses to be further defined and provides a development pathway for novel therapeutics.

Keywords: Antigen-specific T cells; CD134; CD25; CD39; FOXP3; OX40; Treg cell.

Publication types

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

MeSH terms

  • Antigens, CD / immunology*
  • Antigens, Viral / immunology*
  • Apyrase / immunology*
  • CD4 Antigens / immunology*
  • Female
  • Gene Expression Regulation / immunology
  • HIV Core Protein p24 / immunology*
  • HIV Infections / immunology*
  • HIV-1 / immunology*
  • Humans
  • Interleukin-2 Receptor alpha Subunit / immunology*
  • Male
  • Receptors, OX40 / immunology*
  • T-Lymphocytes, Regulatory / immunology*
  • T-Lymphocytes, Regulatory / pathology
  • Viral Load / immunology


  • Antigens, CD
  • Antigens, Viral
  • CD4 Antigens
  • HIV Core Protein p24
  • IL2RA protein, human
  • Interleukin-2 Receptor alpha Subunit
  • Receptors, OX40
  • TNFRSF4 protein, human
  • p24 protein, Human Immunodeficiency Virus Type 1
  • Apyrase
  • CD39 antigen