Infection with the influenza virus induces an immune response to fight the virus; however, this natural defense sometimes results in excessive inflammation that can damage the lungs.
In the Journal of Clinical Investigation, researchers led by Béatrice Riteau at the University of Lyon in Lyon, France, found that mice infected with influenza A had increased PAR1 activity, a protein that attracts inflammatory cells to the site of infection.
To determine if PAR1 plays a role in the damaging inflammation caused by the influenza virus, Riteau and colleagues generated mice that lacked PAR1 or treated them with a drug that blocks PAR1 activity. Interestingly, both groups of mice were protected from influenza virus A infection.
This study suggests that drugs that block PAR1 activity might be useful in treating influenza.