CD71+VISTA+ erythroid cells promote the development and function of regulatory T cells through TGF-β

PLoS Biol. 2018 Dec 14;16(12):e2006649. doi: 10.1371/journal.pbio.2006649. eCollection 2018 Dec.

Abstract

Cell-surface transferrin receptor (CD71+) erythroid cells are abundant in newborns with immunomodulatory properties. Here, we show that neonatal CD71+ erythroid cells express significant levels of V-domain Immunoglobulin (Ig) Suppressor of T Cell Activation (VISTA) and, via constitutive production of transforming growth factor (TGF)- β, play a pivotal role in promotion of naïve CD4+ T cells into regulatory T cells (Tregs). Interestingly, we discovered that CD71+VISTA+ erythroid cells produce significantly higher levels of TGF-β compared to CD71+VISTA- erythroid cells and CD71+ erythroid cells from the VISTA knock-out (KO) mice. As a result, CD71+VISTA+ erythroid cells-compared to CD71+VISTA- and CD71+ erythroid cells from the VISTA KO mice-significantly exceed promotion of naïve CD4+ T cells into induced Tregs (iTreg) via TGF-β in vitro. However, depletion of CD71+ erythroid cells had no significant effects on the frequency of Tregs in vivo. Surprisingly, we observed that the remaining and/or newly generated CD71+ erythroid cells following anti-CD71 antibody administration exhibit a different gene expression profile, evidenced by the up-regulation of VISTA, TGF-β1, TGF-β2, and program death ligand-1 (PDL-1), which may account as a compensatory mechanism for the maintenance of Treg population. We also observed that iTreg development by CD71+ erythroid cells is mediated through the inhibition of key signaling molecules phosphorylated protein kinase B (phospho-Akt) and phosphorylated mechanistic target of rapamycin (phospho-mTOR). Finally, we found that elimination of Tregs using forkhead box P3 (FOXP3)-diptheria toxin receptor (DTR) mice resulted in a significant expansion in the frequency of CD71+ erythroid cells in vivo. Collectively, these studies provide a novel, to our knowledge, insight into the cross-talk between CD71+ erythroid cells and Tregs in newborns. Our results highlight the biological role of CD71+ erythroid cells in the neonatal period and possibly beyond.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antigens, CD / physiology
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / physiology
  • Erythroid Cells / immunology*
  • Erythroid Cells / metabolism
  • Female
  • Forkhead Transcription Factors / metabolism
  • Lymphocyte Activation
  • Male
  • Membrane Proteins / metabolism
  • Membrane Proteins / physiology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Phosphorylation
  • Receptors, Cell Surface
  • Receptors, Transferrin / metabolism
  • Receptors, Transferrin / physiology*
  • T-Lymphocytes, Regulatory / immunology
  • T-Lymphocytes, Regulatory / physiology
  • Transforming Growth Factor beta / metabolism
  • Transforming Growth Factor beta / physiology

Substances

  • Antigens, CD
  • CD71 antigen
  • Forkhead Transcription Factors
  • Membrane Proteins
  • Receptors, Cell Surface
  • Receptors, Transferrin
  • Transforming Growth Factor beta
  • Vsir protein, mouse