Publications

Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Epublish 5 citations

PubMed: 38476229 DOI: 10.3389/fimmu.2024.1302489

Neutrophil-derived Activin-A moderates their pro-NETotic activity and attenuates collateral tissue damage caused by Influenza A virus infection.

Front Immunol 15:1302489

Authors: Georgios Divolis, Evgenia Synolaki, Athanasia Doulou, Ariana Gavriil, Christina C Giannouli, Anastasia Apostolidou, Martyn L Foster, Martin M Matzuk, Panagiotis Skendros, Ioanna-Evdokia Galani, Paschalis Sideras

Affiliations

  • Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation Academy of Athens, Athens, Greece.
  • Experimental Pathology Consultant, London, United Kingdom.
  • Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States.
  • Center for Drug Discovery, Baylor College of Medicine, Houston, TX, United States.
  • Laboratory of Molecular Hematology, Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece.
  • First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece.

Abstract

Background

Pre-neutrophils, while developing in the bone marrow, transcribe the gene and synthesize Activin-A protein, which they store and release at the earliest stage of their activation in the periphery. However, the role of neutrophil-derived Activin-A is not completely understood.

Methods

To address this issue, we developed a neutrophil-specific Activin-A-deficient animal model ( mice) and analyzed the immune response to Influenza A virus (IAV) infection. More specifically, evaluation of body weight and lung mechanics, molecular and cellular analyses of bronchoalveolar lavage fluids, flow cytometry and cell sorting of lung cells, as well as histopathological analysis of lung tissues, were performed in PBS-treated and IAV-infected transgenic animals.

Results

We found that neutrophil-specific Activin-A deficiency led to exacerbated pulmonary inflammation and widespread hemorrhagic histopathology in the lungs of IAV-infected animals that was associated with an exuberant production of neutrophil extracellular traps (NETs). Moreover, deletion of the Activin-A receptor ALK4/ACVR1B in neutrophils exacerbated IAV-induced pathology as well, suggesting that neutrophils themselves are potential targets of Activin-A-mediated signaling. The pro-NETotic tendency of Activin-A-deficient neutrophils was further verified in the context of thioglycollate-induced peritonitis, a model characterized by robust peritoneal neutrophilia. Of importance, transcriptome analysis of Activin-A-deficient neutrophils revealed alterations consistent with a predisposition for NET release.

Conclusion

Collectively, our data demonstrate that Activin-A, secreted by neutrophils upon their activation in the periphery, acts as a feedback mechanism to moderate their pro-NETotic tendency and limit the collateral tissue damage caused by neutrophil excess activation during the inflammatory response.

MeSH

Infections, Pathology, Immune System Diseases, Influenza, Human, Virus Diseases, Cells, Activins, Neutrophils, Viruses, Lung, Influenza A Virus, Tissues

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