Neutrophil-Derived Oncostatin M Triggers Diverse Signaling Pathways during Pneumonia

Area of Science:

• Immunology
• Pulmonology
• Cytokine Signaling

Background:

• Pneumonia causes significant morbidity and mortality despite antimicrobial use.
• Immune response dysfunction underlies severe lung infection sequelae.
• Oncostatin M (OSM), an IL-6 family cytokine, modulates innate immunity.

Purpose of the Study:

• Investigate OSM's role in modulating innate immune pathways during pneumonia.
• Determine the impact of OSM signaling on gene expression and immune cell activation.
• Identify the cellular sources of OSM during lung infection.

Main Methods:

• Transcriptional profiling of whole-lung pneumonia with OSM neutralization.
• Analysis of STAT1, STAT3, and interferon signaling pathways.
• Investigation of neutrophil and macrophage roles in OSM production.

Main Results:

• OSM neutralization altered 241 genes within 6 hours of infection.
• Early downregulation of STAT1, STAT3, and interferon pathways observed with OSM neutralization.
• STAT1 and STAT3 activation increased upon OSM neutralization at 24 hours.
• Neutrophils and macrophages identified as primary OSM sources in pneumonia.

Conclusions:

• OSM produced by recruited neutrophils tunes early innate immune signaling.
• OSM signaling is critical for appropriate immune response modulation in pneumonia.
• OSM plays a key role in improving pneumonia outcomes, suggesting therapeutic potential.