Memory CD4+ T cells lacking expression of CCR7 promote pro-inflammatory cytokine production in patients with diffuse cutaneous systemic sclerosis

Eur J Dermatol. 2019 Oct 1;29(5):468-476. doi: 10.1684/ejd.2019.3645.

Abstract

Systemic sclerosis (SSc) is a predominantly T-cell-mediated autoimmune disorder with a characteristic sequence of Th1 and Th2 inflammation resulting in fibrosis. The contribution of differentiated memory T-cell subpopulations and methylation of CpG regions of Th1- or Th2-specific transcription factor genes on the inflammatory cytokine signature in SSc is not well understood. The study aimed to investigate phenotypic differentiation, the cytokine signature, sensitivity of memory T cells to in vitro suppression by autologous regulatory T cells (Tregs), and methylation of Th1- and Th2-specific transcription factor genes in patients with limited (lcSSc) and diffuse cutaneous SSc (dcSSc) compared to healthy donors (HD). Phenotype/intracellular cytokine production and methylation of Th1- and Th2-specific transcription factor genes were determined by flow cytometry and epigenetic analysis, respectively, and compared between patients with lcSSc, dcSSc and HD. Discrimination of CD4+ T cells that lack CCR7 expression revealed that CCR7- CD4+ memory T cells and effectors are producers of intracellular TNFα, IL-13 and IL-4, particularly in dcSSc. A proportional increase in CCR7- memory T cells was demonstrated by SSc-derived CD4+ T-cells after insufficient suppression by Tregs. A higher level of methylation of GATA3 or STAT4 (Th2- and Th1-specific transcription factor genes, respectively) was observed in dcSSc. An abundance of specific CD4+ memory T-cell subpopulations strongly contributes to the production of pro-inflammatory cytokines in dcSSc. Our results suggest that therapeutic concepts should focus more intensively on the memory phenotype to control T cell-mediated inflammation in SSc patients.

MeSH terms

  • CD4-Positive T-Lymphocytes / immunology*
  • CpG Islands / genetics
  • Cytokines / biosynthesis*
  • DNA Methylation
  • GATA3 Transcription Factor / genetics
  • Gene Expression
  • Humans
  • Leukocyte Common Antigens / immunology
  • Lymphopenia / immunology
  • Receptors, CCR7 / genetics*
  • STAT4 Transcription Factor / genetics
  • Scleroderma, Systemic / genetics
  • Scleroderma, Systemic / immunology*
  • Scleroderma, Systemic / metabolism
  • T-Box Domain Proteins / genetics
  • T-Lymphocytes, Regulatory / immunology
  • Th1 Cells / immunology
  • Th2 Cells / immunology

Substances

  • CCR7 protein, human
  • Cytokines
  • GATA3 Transcription Factor
  • GATA3 protein, human
  • Receptors, CCR7
  • STAT4 Transcription Factor
  • STAT4 protein, human
  • T-Box Domain Proteins
  • T-box transcription factor TBX21
  • Leukocyte Common Antigens
  • PTPRC protein, human