Abstract
Acute respiratory distress syndrome (ARDS) causes significant morbidity and mortality each year. There is a paucity of information regarding the mechanisms necessary for ARDS resolution. Foxp3+ regulatory T cells (Foxp3+ Treg cells) have been shown to be an important determinant of resolution in an experimental model of lung injury. We demonstrate that intratracheal delivery of endotoxin (lipopolysaccharide) elicits alveolar epithelial damage from which the epithelium undergoes proliferation and repair. Epithelial proliferation coincided with an increase in Foxp3+ Treg cells in the lung during the course of resolution. To dissect the role that Foxp3+ Treg cells exert on epithelial proliferation, we depleted Foxp3+ Treg cells, which led to decreased alveolar epithelial proliferation and delayed lung injury recovery. Furthermore, antibody-mediated blockade of CD103, an integrin, which binds to epithelial expressed E-cadherin decreased Foxp3+ Treg numbers and decreased rates of epithelial proliferation after injury. In a non-inflammatory model of regenerative alveologenesis, left lung pneumonectomy, we found that Foxp3+ Treg cells enhanced epithelial proliferation. Moreover, Foxp3+ Treg cells co-cultured with primary type II alveolar cells (AT2) directly increased AT2 cell proliferation in a CD103-dependent manner. These studies provide evidence of a new and integral role for Foxp3+ Treg cells in repair of the lung epithelium.
Original language | English (US) |
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Pages (from-to) | 1440-1451 |
Number of pages | 12 |
Journal | Mucosal Immunology |
Volume | 7 |
Issue number | 6 |
DOIs | |
State | Published - Nov 25 2014 |
Funding
We thank Andre Robinson and James Watkins for expert assistance with tissue processing for histological studies. We thank Dr Mark Soloski, Joe Chrest, and Raffaello Cimbro for their assistance in the Johns Hopkins Bayview Flow Cytometry Core. We thank Dr Enid Neptune for use of the SP-CGFP mice, which were a gift from Dr John Heath and Dr Jo Rae Wright. We thank Dr Alexander Rudensky for use of the Foxp3gfp and Foxp3DTR mice strains. This study was supported by the NIH NRSA F32HL110561 (J.R.M.), NIH R00HL103973 (F.R.D.), NIH R01HL089346 (L.S.K.), and Johns Hopkins Bayview Scholars Program (L.S.K.).
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology