Tirofiban prevents the effects of SARS-CoV-2 spike protein on macrophage activation and endothelial cell death

Area of Science:

• Immunology
• Cell Biology
• Virology

Background:

• SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) viral particles are implicated in tissue inflammation.
• Macrophages are key cells in the inflammatory response to SARS-CoV-2.
• The role of the spike protein in disrupting inflammation resolution is under investigation.

Purpose of the Study:

• To investigate the role of the SARS-CoV-2 spike protein in modulating macrophage polarization and function.
• To determine if the spike protein affects endothelial cell viability and inflammatory signaling.
• To explore the potential of targeting integrin pathways to mitigate spike protein-induced inflammation.

Main Methods:

• In vitro studies using M2-polarized macrophages treated with recombinant spike protein.
• Analysis of macrophage morphology, lymphocyte activation, and STAT1 activation.
• Endothelial cell cultures exposed to spike protein, assessing STAT1 and Bax expression and cell death.
• Treatment with tirofiban, an RGD mimetic, to block beta3 integrin.

Main Results:

• Recombinant spike protein induced M1-like features in M2 macrophages, including rounded morphology and enhanced lymphocyte stimulation.
• Spike protein activated STAT1 in M2 macrophages and endothelial cells, leading to Bax upregulation and cell death.
• Tirofiban treatment reversed spike-induced M2 macrophage costimulatory effects and reduced STAT1 and Bax activation in endothelial cells, mitigating cell death.

Conclusions:

• The SARS-CoV-2 spike protein exhibits pro-inflammatory properties that can affect macrophages and endothelial cells.
• The integrin pathway, specifically beta3 integrin, is involved in mediating some of the inflammatory effects of the spike protein.
• RGD mimetics like tirofiban show potential as therapeutic agents against SARS-CoV-2-induced inflammation.