Zinc supplementation induces CD4 + CD25 + Foxp3 + antigen-specific regulatory T cells and suppresses IFN-γ production by upregulation of Foxp3 and KLF-10 and downregulation of IRF-1

Eur J Nutr. 2017 Aug;56(5):1859-1869. doi: 10.1007/s00394-016-1228-7. Epub 2016 Jun 3.

Abstract

Purpose: The essential trace element zinc plays a fundamental role in immune function and regulation since its deficiency is associated with autoimmunity, allergies, and transplant rejection. Thus, we investigated the influence of zinc supplementation on the Th1-driven alloreaction in mixed lymphocyte cultures (MLC), on generation of antigen-specific T cells, and analyzed underlying molecular mechanisms.

Methods: Cell proliferation and pro-inflammatory cytokine production were monitored by [3H]-thymidine proliferation assay and ELISA, respectively. Analysis of surface and intracellular T cell marker was performed by flow cytometry. Western blotting and mRNA analysis were used for Foxp3, KLF-10, and IRF-1 expression.

Results: Zinc supplementation on antigen-specific T cells in physiological doses (50 µM) provokes a significant amelioration of cell proliferation and pro-inflammatory cytokine production after reactivation compared to untreated controls. Zinc administration on MLC results in an increased induction and stabilization of CD4+CD25+Foxp3+ and CD4+CD25+CTLA-4+ T cells (p < 0.05). The effect is based on zinc-induced upregulation of Foxp3 and KLF-10 and downregulation of IRF-1. However, in resting lymphocytes zinc increases IRF-1.

Conclusion: In summary, zinc is capable of ameliorating the allogeneic immune reaction by enhancement of antigen-specific iTreg cells due to modulation of essential molecular targets: Foxp3, KLF-10, and IRF-1. Thus, zinc can be seen as an auspicious tool for inducing tolerance in adverse immune reactions.

Keywords: Foxp3; IRF-1; KLF-10; Mixed lymphocyte culture (MLC); Regulatory T cells; Zinc.

MeSH terms

  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Cytokines / metabolism
  • Down-Regulation
  • Early Growth Response Transcription Factors / genetics
  • Early Growth Response Transcription Factors / metabolism*
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / metabolism*
  • Humans
  • Interferon Regulatory Factor-1 / genetics
  • Interferon Regulatory Factor-1 / metabolism*
  • Interferon-gamma / biosynthesis*
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism*
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Lymphocyte Culture Test, Mixed
  • T-Lymphocytes, Regulatory / metabolism*
  • Up-Regulation
  • Zinc / pharmacology*

Substances

  • Cytokines
  • Early Growth Response Transcription Factors
  • FOXP3 protein, human
  • Forkhead Transcription Factors
  • IFNG protein, human
  • IRF1 protein, human
  • Interferon Regulatory Factor-1
  • KLF10 protein, human
  • Kruppel-Like Transcription Factors
  • Interferon-gamma
  • Zinc