pubmed.ncbi.nlm.nih.gov

Cutting Edge: Regulatory T Cells Facilitate Cutaneous Wound Healing - PubMed

  • ️Fri Jan 01 2016

Cutting Edge: Regulatory T Cells Facilitate Cutaneous Wound Healing

Audrey Nosbaum et al. J Immunol. 2016.

Abstract

Foxp3-expressing regulatory T cells (Tregs) reside in tissues where they control inflammation and mediate tissue-specific functions. The skin of mice and humans contain a large number of Tregs; however, the mechanisms of how these cells function in skin remain largely unknown. In this article, we show that Tregs facilitate cutaneous wound healing. Highly activated Tregs accumulated in skin early after wounding, and specific ablation of these cells resulted in delayed wound re-epithelialization and kinetics of wound closure. Tregs in wounded skin attenuated IFN-γ production and proinflammatory macrophage accumulation. Upon wounding, Tregs induce expression of the epidermal growth factor receptor (EGFR). Lineage-specific deletion of EGFR in Tregs resulted in reduced Treg accumulation and activation in wounded skin, delayed wound closure, and increased proinflammatory macrophage accumulation. Taken together, our results reveal a novel role for Tregs in facilitating skin wound repair and suggest that they use the EGFR pathway to mediate these effects.

Copyright © 2016 by The American Association of Immunologists, Inc.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Tregs facilitate skin wound repair

Foxp3-DTR or WT mice were treated with DT 2 days prior to full thickness wounding of dorsal skin and every 2 days thereafter. (A) Representative images of wounds at specific times after injury (D, day). (B) Mean percentage of wound closure with time after injury. (C) Mean percentage of wound closure with time after injury between WT and Foxp3-DTR mice treated with DT “early” after wounding. (D) Representative plot of mean percentage of wound closure 7 days after wounding. Each symbol represents an individual wound. (E) Percent of wound closure with time after injury between WT and Foxp3-DTR mice treated with DT ‘late’ after wounding. (F) Representative histology of skin wounds at day 7 post-injury between WT and Foxp3-DTR mice treated ‘early’ with DT. Arrowheads denote wound edges; he, hypertrophic epithelium; gt, granulation tissue; scale bars, 200μm. Representative data is shown from ≥ 3 replicate experiments with ≥ 3 mice per group. Error bars in all panels represent the mean ± SEM. ns p>0.05, * p≤0.05, ** p≤0.01, *** p≤0.001, **** p≤0.0001.

Figure 2
Figure 2. Activated Tregs accumulate in wounded skin

Full thickness wounds were introduced to the dorsal skin of WT mice and skin-infiltrating CD4+ T cells were assayed at specific time points by flow cytometry. (A) Representative flow cytometric plots and percentage of Tregs in skin with time after wounding. Pre-gated on live CD45+CD3+CD4+ cells. (B, C, D) Percent of skin Tregs that express high levels of CD25, CTLA-4, and ICOS with time after wounding. Pre-gated on live CD45+CD3+CD4+Foxp3+ cells. Each symbol represents an individual mouse. Bars represent means. Representative data is shown from ≥ 3 replicate experiments with ≥ 3 mice per group. ns p>0.05, * p≤0.05, ** p≤0.01, *** p≤0.001, **** p≤0.0001.

Figure 3
Figure 3. Tregs limit the accumulation of IFNγ-producing T cells and pro-inflammatory macrophages in wounded skin

(A) Full thickness wounds were introduced to the dorsal skin of WT mice and the percentage of skin-infiltrating pro-inflammatory macrophages were assayed at specific time points by flow cytometry. (B) Foxp3-DTR or WT mice were treated with DT ‘early’ after wounding and percentage of skin-infiltrating pro-inflammatory macrophages were assayed at specific time points by flow cytometry. (C) Absolute number of cytokine producing T cell subsets in skin 7 days after wounding in DT-treated Foxp3-DTR or WT mice as measured by intracellular cytokine staining using flow cytometry. Representative data is shown from ≥ 3 replicate experiments with ≥ 3 mice per group. Error bars in all panels represent the mean ± SEM. ns p>0.05, * p≤0.05, ** p≤0.01, *** p≤0.001, **** p≤0.0001.

Figure 4
Figure 4. The EGFR pathway is required for Treg function in wounded skin

(A) Foxp3-expressing and non-expressing CD4+ T cells were purified from skin and skin draining lymph nodes (SDLN) of Foxp3 reporter (Foxp3-DTR) mice. qRT-PCR for EGFR was performed on purified cells 3 days after full thickness wounding. Results are fold change (FC) relative to β2microglobulin (B2M). (B) Mean percentage of wound closure and a representative plot of percentage of wound closure for individual wounds 3 days after injury between Foxp3creEGFRfl/fl and control (Ctl) mice. Control mice represent either WT or Foxp3creEGFRwt/wt mice. (C) Percent and absolute number of Tregs in skin 3 days after wounding. Pre-gated on live CD45+CD3+CD4+ cells. (D) Percent of Tregs that express high levels of CD25 and total CTLA-4 3 days after wounding. (E) Percentage of skin-infiltrating pro-inflammatory macrophages 3 days after wounding as assayed by flow cytometry. Pre-gated on CD45+CD11bhighF4/80+Ly-6Glowcells. Representative data is shown from ≥ 3 replicate experiments with ≥ 4 mice per group. Error bars in all panels represent the mean ± SEM. AU, arbitrary units. ns p>0.05, * p≤0.05, ** p≤0.01

Similar articles

Cited by

References

    1. Gratz IK, Truong HA, Yang SHY, Maurano MM, Lee K, Abbas AK, Rosenblum MD. Cutting Edge: memory regulatory t cells require IL-7 and not IL-2 for their maintenance in peripheral tissues. J Immunol Baltim Md 1950. 2013;190:4483–4487. - PMC - PubMed
    1. Sanchez Rodriguez R, Pauli ML, Neuhaus IM, Yu SS, Arron ST, Harris HW, Yang SH-Y, Anthony BA, Sverdrup FM, Krow-Lucal E, MacKenzie TC, Johnson DS, Meyer EH, Löhr A, Hsu A, Koo J, Liao W, Gupta R, Debbaneh MG, Butler D, Huynh M, Levin EC, Leon A, Hoffman WY, McGrath MH, Alvarado MD, Ludwig CH, Truong H-A, Maurano MM, Gratz IK, Abbas AK, Rosenblum MD. Memory regulatory T cells reside in human skin. J Clin Invest. 2014;124:1027–1036. - PMC - PubMed
    1. Bodnar RJ. Epidermal Growth Factor and Epidermal Growth Factor Receptor: The Yin and Yang in the Treatment of Cutaneous Wounds and Cancer. Adv Wound Care. 2013;2:24–29. - PMC - PubMed
    1. Arpaia N, Green JA, Moltedo B, Arvey A, Hemmers S, Yuan S, Treuting PM, Rudensky AY. A Distinct Function of Regulatory T Cells in Tissue Protection. Cell. 2015;162:1078–1089. - PMC - PubMed
    1. Burzyn D, Kuswanto W, Kolodin D, Shadrach JL, Cerletti M, Jang Y, Sefik E, Tan TG, Wagers AJ, Benoist C, Mathis D. A special population of regulatory T cells potentiates muscle repair. Cell. 2013;155:1282–1295. - PMC - PubMed

Publication types

MeSH terms

Substances