Autophagy-dependent regulatory T cells are critical for the control of graft-versus-host disease
Laëtitia Le Texier, … , Geoffrey R. Hill, Kelli P.A. MacDonald
Laëtitia Le Texier, … , Geoffrey R. Hill, Kelli P.A. MacDonald
Published September 22, 2016
Citation Information: JCI Insight. 2016;1(15):e86850. https://doi.org/10.1172/jci.insight.86850.
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Research Article Immunology Transplantation

Autophagy-dependent regulatory T cells are critical for the control of graft-versus-host disease

Abstract

Regulatory T cells (Tregs) play a crucial role in the maintenance of peripheral tolerance. Quantitative and/or qualitative defects in Tregs result in diseases such as autoimmunity, allergy, malignancy, and graft-versus-host disease (GVHD), a serious complication of allogeneic stem cell transplantation (SCT). We recently reported increased expression of autophagy-related genes (Atg) in association with enhanced survival of Tregs after SCT. Autophagy is a self-degradative process for cytosolic components that promotes cell homeostasis and survival. Here, we demonstrate that the disruption of autophagy within FoxP3+ Tregs (B6.Atg7fl/fl-FoxP3cre+) resulted in a profound loss of Tregs, particularly within the bone marrow (BM). This resulted in dysregulated effector T cell activation and expansion, and the development of enterocolitis and scleroderma in aged mice. We show that the BM compartment is highly enriched in TIGIT+ Tregs and that this subset is differentially depleted in the absence of autophagy. Moreover, following allogeneic SCT, recipients of grafts from B6.Atg7fl/fl-FoxP3cre+ donors exhibited reduced Treg reconstitution, exacerbated GVHD, and reduced survival compared with recipients of B6.WT-FoxP3cre+ grafts. Collectively, these data indicate that autophagy-dependent Tregs are critical for the maintenance of tolerance after SCT and that the promotion of autophagy represents an attractive immune-restorative therapeutic strategy after allogeneic SCT.

Authors

Laëtitia Le Texier, Katie E. Lineburg, Benjamin Cao, Cameron McDonald-Hyman, Lucie Leveque-El Mouttie, Jemma Nicholls, Michelle Melino, Blessy C. Nalkurthi, Kylie A. Alexander, Bianca Teal, Stephen J. Blake, Fernando Souza-Fonseca-Guimaraes, Christian R. Engwerda, Rachel D. Kuns, Steven W. Lane, Michele Teng, Charis Teh, Daniel Gray, Andrew D. Clouston, Susan K. Nilsson, Bruce R. Blazar, Geoffrey R. Hill, Kelli P.A. MacDonald

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Figure 4

Characterization of BM and splenic TIGIT+ Tregs.

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Characterization of BM and splenic TIGIT+ Tregs. (A and B) Flow cytometr...
(A and B) Flow cytometry analysis of splenic and BM TIGIT+ and TIGITneg CD4+FoxP3-GFP+ or FoxP3-RFP+ Tregs from FoxP3-GFP or IL-10-GFP-FoxP3-RFP naive mice. Expression of KLRG1, CD62L, CD44, CD69, CD25, PD-1, CD73, GITR, ICOS, CTLA4, ICAM-1, and IL-10. The isotype control represents staining of pooled BM and spleen cells. Representative histograms of phenotype analysis (n = 3 from 3 independent experiments). (C) Representative histograms of BCL-2 expression in splenic and BM TIGIT+ and TIGITneg CD4+FoxP3+ cells from C57BL/6 naive mice (n = 3 from 1 experiment). (D) Frequency (%) and intensity (geometric mean) of LC3 expression in splenic and BM TIGIT+ and TIGITneg CD4+CD25+ Tregs from LC3-GFP mice (n = 9 from 3 independent experiments). (E) ATG7 transcripts quantification by RT-qPCR in sorted TIGIT+ and TIGITneg CD4+FoxP3-GFP+ splenic Tregs from FoxP3-GFP naive mice (n = 6 from 3 independent experiments). Data are shown as mean ± SEM. Statistical significance was determined using a Wilcoxon matched-paired test (*P < 0.05; **P < 0.01). Statistical analyses were performed using GraphPad Prism version 6.01 software. TIGIT, T cell immunoreceptor with Ig and ITIM domains; RFP, red fluorescent protein; KLRG1, coinhibitory receptor killer cell lectin-like receptor G1; PD-1, programmed cell death protein 1; GITR, glucocorticoid-induced TNFR-related protein; ICOS, inducible T cell costimulator; CTLA4, cytotoxic T lymphocyte–associated protein 4; ICAM-1, intercellular adhesion molecule 1; BCL-2, B cell lymphoma 2; LC3, microtubule-associated protein light chain 3; Atg, autophagy-related gene.