AUTHOR=Okamoto Masaaki , Kuratani Ayumi , Okuzaki Daisuke , Kamiyama Naganori , Kobayashi Takashi , Sasai Miwa , Yamamoto Masahiro 

TITLE=Tff1-expressing Tregs in lung prevent exacerbation of Bleomycin-induced pulmonary fibrosis

JOURNAL=Frontiers in Immunology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1440918

DOI=10.3389/fimmu.2024.1440918

ISSN=1664-3224

ABSTRACT=<p>Bleomycin (BLM) induces lung injury, leading to inflammation and pulmonary fibrosis. Regulatory T cells (Tregs) maintain self-tolerance and control host immune responses. However, little is known about their involvement in the pathology of pulmonary fibrosis. Here we show that a unique Treg subset expressing trefoil factor family 1 (Tff1) emerges in the BLM-injured lung. These Tff1-expressing Tregs (Tff1-Tregs) were induced by IL-33. Moreover, although Tff1 ablation in Tregs did not change the pathological condition, selective ablation of Tff1-Tregs using an intersectional genetic method promoted pro-inflammatory features of macrophages in the injured lung and exacerbated the fibrosis. Taken together, our study revealed the presence of a unique Treg subset expressing Tff1 in BLM-injured lungs and their critical role in the injured lung to ameliorate fibrosis.</p>