Journal Article

IL4Rα Signaling Abrogates Hypoxic Neutrophil Survival and Limits Acute Lung Injury Responses In Vivo

Ghesquiere, Bart, Willson, Joseph A., Jenkins, Steve J., Lynch, Ruairi W., Walmsley, Sarah R., Whyte, Moira K. B., Morrison, Tyler, Clark, Eilidh, Mirchandani, Ananda S., Sadiku, Pranvera, Small, Donna, Coelho, Patricia, Murphy, Fiona, Delaney, Liam, McAuley, Danny, Mazzone, Massimilliano, Griffith, David, Dickinson, Rebecca S., O’Kane, Cecilia, Watts, Emily R., Carmeliet, Peter, Harris, Alison J.

2019

Overview

Abstract Rationale Acute respiratory distress syndrome is defined by the presence of systemic hypoxia and consequent on disordered neutrophilic inflammation. Local mechanisms limiting the duration and magnitude of this neutrophilic response remain poorly understood. Objectives To test the hypothesis that during acute lung inflammation tissue production of proresolution type 2 cytokines (IL-4 and IL-13) dampens the proinflammatory effects of hypoxia through suppression of HIF-1α (hypoxia-inducible factor-1α)-mediated neutrophil adaptation, resulting in resolution of lung injury. Methods Neutrophil activation of IL4Ra (IL-4 receptor α) signaling pathways was explored ex vivo in human acute respiratory distress syndrome patient samples, in vitro after the culture of human peripheral blood neutrophils with recombinant IL-4 under conditions of hypoxia, and in vivo through the study of IL4Ra-deficient neutrophils in competitive chimera models and wild-type mice treated with IL-4. Measurements and Main Results IL-4 was elevated in human BAL from patients with acute respiratory distress syndrome, and its receptor was identified on patient blood neutrophils. Treatment of human neutrophils with IL-4 suppressed HIF-1α–dependent hypoxic survival and limited proinflammatory transcriptional responses. Increased neutrophil apoptosis in hypoxia, also observed with IL-13, required active STAT signaling, and was dependent on expression of the oxygen-sensing prolyl hydroxylase PHD2. In vivo, IL-4Ra–deficient neutrophils had a survival advantage within a hypoxic inflamed niche; in contrast, inflamed lung treatment with IL-4 accelerated resolution through increased neutrophil apoptosis. Conclusions We describe an important interaction whereby IL4Rα-dependent type 2 cytokine signaling can directly inhibit hypoxic neutrophil survival in tissues and promote resolution of neutrophil-mediated acute lung injury.

• Publisher: Oxford University Press,American Thoracic Society
• Subject: Acute Lung Injury - immunology / Acute Lung Injury - metabolism / Angiogenesis / Animals / Apoptosis / Apoptosis - drug effects / Blood & organ donations / Cell Hypoxia - immunology / Cell Survival - drug effects / Cytokines / Gene Expression Regulation / Humans / Hypoxia / Hypoxia-Inducible Factor 1, alpha Subunit - metabolism / Inflammation / Interleukin-4 - immunology / Interleukin-4 - metabolism / Interleukin-4 - pharmacology / Interleukin-4 Receptor alpha Subunit - genetics / Interleukin-4 Receptor alpha Subunit - immunology / Interleukin-4 Receptor alpha Subunit - metabolism / Lungs / Medical research / Mice / Mice, Knockout / Neutrophils / Neutrophils - drug effects / Neutrophils - immunology / Neutrophils - metabolism / Original / Receptors, Cell Surface - immunology / Receptors, Cell Surface - metabolism / Respiratory distress syndrome / Respiratory Distress Syndrome - immunology / Respiratory Distress Syndrome - metabolism / Sepsis / Signal Transduction / STAT Transcription Factors - metabolism