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.
View: Text | PDF
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

×

Figure 5

G-CSF induces Treg mobilization.

Options: View larger image (or click on image) Download as PowerPoint
G-CSF induces Treg mobilization. (A) Representative zebra plot of flow c...
(A) Representative zebra plot of flow cytometry analysis and absolute number (#) of TIGIT+ and TIGITneg CD4+FoxP3-GFP+ Tregs from spleen and BM of BALB/c FoxP3-GFP mice after saline or G-CSF injections (10 μg/mice; 1 injection/day for 6 days) (n = 6 from 2 independent experiments). (B) Representative zebra plot and histogram of flow cytometry analysis of CXCR4 expression on FoxP3+CD4+CD8–CD3+ Tregs in spleen and BM of naive C57BL/6 naive mice (n = 3 from 1 experiment). The isotype control represents staining of pooled BM and spleen cells. (C) Experiments performed at CSIRO. Absolute number (#) of HSPCs (LSK; lineagenegSca-1+c-kit+), HSCs (LSKSLAM; LSKCD150+CD48neg), B220negGr-1negMac-1negCD4+FoxP3+ Tregs, TIGIT+ B220negGr-1negMac-1negCD4+FoxP3+ Tregs, and TIGITneg B220negGr-1negMac-1negCD4+FoxP3+ Tregs from peripheral blood of B6.FoxP3-GFP mice after saline, G-CSF (250 μg/kg, 2 injections/day for 4 days), or AMD3100 injection (n = 4–12 from 3 independent experiments). Data are shown as mean ± SEM. Statistical significance was determined using an unpaired 2-tailed Mann-Whitney U test (*P < 0.05; **P < 0.01; ****P < 0.0001). (D) Geometric mean of LC3 expression in splenic TIGIT+ and TIGITneg CD4+FoxP3+ Tregs from C57BL/6 naive mice incubated in vitro for 2 hours without (Nil) or with (G-CSF) plus CQ (n = 4 from 2 independent experiments). Data are shown as mean ± SEM. Statistical significance was determined using a paired t test (*P < 0.05; **P < 0.01). Statistical analyses were performed using GraphPad Prism version 6.01 software. G-CSF, granulocyte-colony stimulating factor; TIGIT, T cell immunoreceptor with Ig and ITIM domains; HSPC, hematopoietic stem and progenitor cells; HSC, hematopoietic stem cells; LC3, microtubule-associated protein light chain 3; CQ, chloroquine.