IL-33 Mediates Pseudomonas Induced Airway Fibrogenesis and Is Associated with CLAD

Authors

Mudassir M Banday
Sangeetha B Rao
Shruthi Shankar
Mudasir A Khanday
Jon Finan
Edward O'Neill
Antonio Coppolino
Andreas Seyfang
Archit Kumar
Daniel E Rinewalt
Hilary J Goldberg
Ann Woolley
Hari Reddy Mallidi
Gary Visner
Amit Gaggar
Kapil N Patel
Nirmal S Sharma

Publication Date

1-1-2023

Journal

The Journal of Heart and Lung Transplantation

Abstract

BACKGROUND: Long term outcomes of lung transplantation are impacted by the occurrence of chronic lung allograft dysfunction (CLAD). Recent evidence suggests a role for the lung microbiome in the occurrence of CLAD, but the exact mechanisms are not well defined. We hypothesize that the lung microbiome inhibits epithelial autophagic clearance of pro-fibrotic proteins in an IL-33 dependent manner, thereby augmenting fibrogenesis and risk for CLAD.

METHODS: Autopsy derived CLAD and non-CLAD lungs were collected. IL-33, P62 and LC3 immunofluorescence was performed and assessed using confocal microscopy. Pseudomonas aeruginosa (PsA), Streptococcus Pneumoniae (SP), Prevotella Melaninogenica (PM), recombinant IL-33 or PsA-lipopolysaccharide was co-cultured with primary human bronchial epithelial cells (PBEC) and lung fibroblasts in the presence or absence of IL-33 blockade. Western blot analysis and quantitative reverse transcription (qRT) PCR was performed to evaluate IL-33 expression, autophagy, cytokines and fibroblast differentiation markers. These experiments were repeated after siRNA silencing and upregulation (plasmid vector) of Beclin-1.

RESULTS: Human CLAD lungs demonstrated markedly increased expression of IL-33 and reduced basal autophagy compared to non-CLAD lungs. Exposure of co-cultured PBECs to PsA, SP induced IL-33, and inhibited PBEC autophagy, while PM elicited no significant response. Further, PsA exposure increased myofibroblast differentiation and collagen formation. IL-33 blockade in these co-cultures recovered Beclin-1, cellular autophagy and attenuated myofibroblast activation in a Beclin-1 dependent manner.

CONCLUSION: CLAD is associated with increased airway IL-33 expression and reduced basal autophagy. PsA induces a fibrogenic response by inhibiting airway epithelial autophagy in an IL-33 dependent manner.

Keywords

Humans, Beclin-1, Pseudomonas, Interleukin-33, Arthritis, Psoriatic, Lung, Autophagy, CLAD, IL33, microbiome, autophagy, fibrogenesis

Comments

Supplementary Materials

This article has been corrected. See J Heart Lung Transplant. 2023 December 02; : .

PMID: 37014805