Format

Send to

Choose Destination
FASEB J. 2019 Aug 9:fj201901265R. doi: 10.1096/fj.201901265R. [Epub ahead of print]

The annexin A1/FPR2 signaling axis expands alveolar macrophages, limits viral replication, and attenuates pathogenesis in the murine influenza A virus infection model.

Author information

1
Center for Molecular Biology of Inflammation, Institute of Medical Biochemistry, University of Muenster, Muenster, Germany.
2
Cells-in-Motion Cluster of Excellence, University of Muenster, Muenster, Germany.
3
Center for Molecular Biology of Inflammation, Institute of Virology, University of Muenster, Muenster, Germany.
4
Section for Experimental Virology, Institute of Medical Microbiology, Jena University Hospital, Jena, Germany.
5
Department of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany.
6
Institute of Anatomy, Rostock University Medical Center, Rostock, Germany.
#
Contributed equally

Abstract

Pattern recognition receptors (PRRs) are key elements in the innate immune response. Formyl peptide receptor (FPR) 2 is a PRR that, in addition to proinflammatory, pathogen-derived compounds, also recognizes the anti-inflammatory endogenous ligand annexin A1 (AnxA1). Because the contribution of this signaling axis in viral infections is undefined, we investigated AnxA1-mediated FPR2 activation on influenza A virus (IAV) infection in the murine model. AnxA1-treated mice displayed significantly attenuated pathology upon a subsequent IAV infection with significantly improved survival, impaired viral replication in the respiratory tract, and less severe lung damage. The AnxA1-mediated protection against IAV infection was not caused by priming of the type I IFN response but was associated with an increase in the number of alveolar macrophages (AMs) and enhanced pulmonary expression of the AM-regulating cytokine granulocyte-M-CSF (GM-CSF). Both AnxA1-mediated increase in AM levels and GM-CSF production were abrogated when mouse (m)FPR2 signaling was antagonized but remained up-regulated in mice genetically deleted for mFPR1, an mFPR2 isoform also serving as AnxA1 receptor. Our results indicate a novel protective function of the AnxA1-FPR2 signaling axis in IAV pathology via GM-CSF-associated maintenance of AMs, expanding knowledge on the potential use of proresolving mediators in host defense against pathogens.-Schloer, S., Hübel, N., Masemann, D., Pajonczyk, D., Brunotte, L., Ehrhardt, C., Brandenburg, L.-O., Ludwig, S., Gerke, V., Rescher, U. The annexin A1/FPR2 signaling axis expands alveolar macrophages, limits viral replication, and attenuates pathogenesis in the murine influenza A virus infection model.

KEYWORDS:

innate immune system; mucosal immunity; pattern recognition receptors

PMID:
31398292
DOI:
10.1096/fj.201901265R

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center