Figure 3: Influenza titers were controlled through extracellular MPO and on transcriptional level through PAR2. (a, b) DF from stimulated neutrophils was supplemented with H2O2, and the virucidal activity was determined. DF from PAR2 agonist treated neutrophils disrupted IAV. (c) Application of a MPO inhibitor enhanced viral titers. Interestingly, despite MPO inhibition, PAR2 activation reduced viral replication in neutrophils. (d) Analysis of viral gene replication displayed reduced NS-1 mRNA expression in PAR2 agonist stimulated neutrophils. IFNγ had no effect on viral replication. For student’s t-test: #,* ; ** ; *** . The symbol * marks the significance as compared to control and the symbol # as compared to IFNγ sample.