Open AccessBronchial Epithelial Tet2 Maintains Epithelial Integrity during Acute Pseudomonas aeruginosa Pneumonia
Author(s) -
Wanhai Qin,
Xanthe Brands,
Cornelis van’t Veer,
Alex F. de Vos,
Brendon P. Scicluna,
Tom van der Poll
Publication year - 2020
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.00603-20
Subject(s) - biology , cxcl1 , pseudomonas aeruginosa , chemokine , cxcl2 , immunology , ccl20 , immune system , pneumonia , microbiology and biotechnology , occludin , innate immune system , respiratory tract , tight junction , respiratory system , medicine , chemokine receptor , bacteria , genetics , anatomy
Respiratory epithelial cells are important for pulmonary innate immune responses during Pseudomonas aeruginosa infection. Tet methylcytosine dioxygenase 2 (Tet2) has been implicated in the regulation of host defense by myeloid and lymphoid cells, but whether Tet2 also contributes to epithelial responses during pneumonia is unknown. The aim of this study was to investigate the role of bronchial epithelial Tet2 in acute pneumonia caused by P. aeruginosa To this end, we crossed mice with Tet2 flanked by two Lox-P sites ( Tet2 fl/fl mice) with mice expressing Cre recombinase under the bronchial epithelial cell-specific Cc10 promoter ( Cc10 Cre mice) to generate bronchial epithelial cell-specific Tet2-deficient ( Tet2 fl/fl Cc10 Cre ) mice. Six hours after infection with P. aeruginosa, Tet2 fl/fl Cc10 Cre and wild-type mice had similar bacterial loads in bronchoalveolar lavage fluid (BALF). At this time point, Tet2 fl/fl Cc10 Cre mice displayed reduced mRNA levels of the chemokines Cxcl1, Cxcl2, and Ccl20 in bronchial brushes. However, Cxcl1, Cxcl2, and Ccl20 protein levels and leukocyte recruitment in BALF were not different between groups. Tet2 fl/fl Cc10 Cre mice had increased protein levels in BALF after infection, indicating a disturbed epithelial barrier function, which was corroborated by reduced mRNA expression of tight junction protein 1 and occludin in bronchial brushes. Differences detected between Tet2 fl/fl Cc10 Cre and wild-type mice were no longer present at 24 h after infection. These results suggest that bronchial epithelial Tet2 contributes to maintaining epithelial integrity by enhancing intracellular connections between epithelial cells during the early phase of P. aeruginosa pneumonia.