Human CD4+ HLA-G+ regulatory T cells are potent suppressors of graft-versus-host disease in vivo

FASEB J. 2014 Aug;28(8):3435-45. doi: 10.1096/fj.14-251074. Epub 2014 Apr 17.


CD4(+) T cells expressing the immunotolerizing molecule HLA-G have been described as a unique human thymus-derived regulatory T (tTreg) cell subset involved in immunoregulation and parenchymal homeostasis during infectious and autoimmune inflammation. We compared properties and molecular characteristics of human CD4(+)HLA-G(+) with those of CD4(+)CD25(+)FoxP3-expressing tTreg cells using in vitro studies of T-cell receptor (TCR) signaling, single-cell electrophysiology, and functional in vivo studies. Both tTreg populations are characterized by alterations in proximal-signaling pathways on TCR stimulation and a hyperpolarization of the plasma membrane when compared to conventional CD4(+) T cells. However, both clearly differ in phenotype and pattern of secreted cytokines, which results in distinct mechanisms of suppression: While CD4(+)HLA-G(+) cells secrete high levels of inhibitory molecules (IL-10, soluble HLA-G, IL-35), CD4(+)CD25(+)FoxP3(+) cells express these molecules at significantly lower levels and seem to exert their function mainly in a contact-dependent manner via cyclic adenosine-monophosphate. Finally we demonstrate that human CD4(+)HLA-G(+) tTreg cells significantly ameliorated graft-versus-host disease in a humanized mouse model as a first proof of their in vivo relevance. Our data further characterize and establish CD4(+)HLA-G(+) cells as a potent human tTreg population that can modulate polyclonal adaptive immune responses in vivo and thus being a promising candidate for potential clinical applications in the future.

Keywords: human leukocyte antigen G; humanized mouse model; immune tolerance; membrane potential of tTreg cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adoptive Transfer*
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / transplantation
  • Calcium Signaling
  • Cytokines / biosynthesis
  • Cytokines / metabolism
  • Forkhead Transcription Factors / analysis
  • Graft vs Host Disease / immunology
  • Graft vs Host Disease / prevention & control*
  • HLA-G Antigens / immunology
  • Heterografts
  • Humans
  • Immunosuppression Therapy / methods*
  • Interleukin-2 Receptor alpha Subunit / analysis
  • Leukocytes, Mononuclear / transplantation*
  • Lymphocyte Activation
  • Membrane Potentials
  • Mice
  • Mice, Inbred NOD
  • Specific Pathogen-Free Organisms
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / transplantation
  • T-Lymphocytes, Regulatory / immunology*
  • T-Lymphocytes, Regulatory / transplantation


  • Cytokines
  • FOXP3 protein, human
  • Forkhead Transcription Factors
  • HLA-G Antigens
  • IL2RA protein, human
  • Interleukin-2 Receptor alpha Subunit