PB0751 - Platelet glycoprotein VI drives acute pulmonary inflammation by promoting neutrophil recruitment, clustering and NETosis

Monday, June 26, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Philipp Burkard, MSc

PhD student
University Hospital Würzburg, Institute of Experimental Biomedicine, Chair of Experimental Biomedicine I, Würzburg, Germany
Würzburg, Bayern, Germany

Co-Author(s)

CS

Charlotte Schonhart

MD student
Institute of Experimental Biomedicine - Chair I, University Hospital Würzburg, University of Würzburg, Germany
Würzburg, Bayern, Germany
TV

Timo Vögtle

Postdoc
Institute of Experimental Biomedicine - Chair I, University Hospital Würzburg, University of Würzburg,Germany
Würzburg, Bayern, Germany
DK

David Köhler

Postdoc
Department of Anesthesiology and Intensive Care Medicine, University Hospital, Tübingen, Germany
Tübingen, Baden-Wurttemberg, Germany
LT

Linyan Tang

PhD student
Department of Anesthesiology and Intensive Care Medicine, University Hospital, Tübingen, Germany
Tübingen, Baden-Wurttemberg, Germany
KH

Katherina Hemmen

Postdoc
Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, Germany
Würzburg, Bayern, Germany
KH

Katrin Heinze

Professor
Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, Germany
Würzburg, Bayern, Germany
HH

Heike M. Hermanns

Professor
Medical Clinic II, University Hospital Würzburg, University of Würzburg, Germany
Würzburg, Bayern, Germany
PR

Peter Rosenberger

Professor
Department of Anesthesiology and Intensive Care Medicine, University Hospital, Tübingen, Germany
Tübingen, Baden-Wurttemberg, Germany
BN

Bernhard Nieswandt

Professor
Institute of Experimental Biomedicine - Chair I, University Hospital Würzburg and Rudolf Virchow Center for Integrative and Translational Biomaging, University of Würzburg, Germany
Würzburg, Bayern, Germany

Background: Acute lung injury (ALI) and the more severe acute respiratory distress syndrome (ARDS) are life-threatening, inflammatory disease states in which the lung function is critically compromised. Excessive infiltration of neutrophils into the pulmonary airspace is the main cause for the acute inflammation and lung injury. A role of platelets in the pathogenesis of this disease is suggested, but the underlying mechanisms remained elusive.

Aims: We aimed to mechanistically dissect the contribution of the platelet receptor glycoprotein (GP)VI to thrombo-inflammation in the acute phase of experimental lipopolysaccharide (LPS)-induced ALI in mice.

Methods: Gp6-knockout (Gp6-/-) and wild-type mice, treated with the anti-GPVI antibody JAQ1, were utilized. Acute alveolar inflammation was induced by intranasal instillation of LPS. A bronchoalveolar lavage (BAL) was performed after 4 hours and infiltrated cells, myeloperoxidase (MPO)-activity, hemoglobin content and cytokine levels were determined. MPO-activity and Evans blue dye extravasation in the lung were analyzed. Multi-color high-resolution confocal microscopy of cryosections and intravital microscopy (IVM) of the ventilated lung was performed to assess cell-cell interactions during acute inflammation.

Results: Control mice displayed severe pulmonary and blood neutrophilia, hypothermia, and increased blood lactate levels in response to LPS. In contrast, Gp6-/- mice as well as anti-GPVI-treated wild-type mice were markedly protected from pulmonary and systemic compromises, while inflammatory bleeding was not increased. IVM revealed less stable interactions of platelets with neutrophils in anti-GPVI-treated animals compared to controls, leading to reduced platelet-neutrophil complexes (PNCs). Furthermore, vascular crawling and adhesion of neutrophils to endothelial cells were diminished leading to reduced neutrophil transmigration and alveolar infiltrates. Remarkably, neutrophil activation was significantly inhibited in anti-GPVI-treated animals compared to controls reflected by mitigated cluster- and neutrophil extracellular trap (NET)-formation.

Conclusion(s): GPVI drives alveolar inflammation by directly promoting PNC-formation, neutrophil recruitment and activation. GPVI inhibition might be a promising strategy to reduce the excessive pulmonary thrombo-inflammation causing ALI.