Fig 1. Neutrophil H2O2 production in response to IAV or IAV + LL-37derived peptides–Neutrophils were treated with control buffer, IAV, or combinations of IAV and GI-20, LL23, or LL23V9 (panel A) or CRAMP, KR-12 or LK-13 (panel B) and H2O2 responses were measured by the fluorescent scopoletin assay.

Decrease in scopoletin fluorescence corresponds to H₂O₂ production. A dose response using GI-20 was performed (doses as indicated). For the other peptides 32 μg/ml was used. IAV alone elicited increased H₂O₂ generation as compared to control buffer. Pre-incubation of IAV with GI-20 caused significant further increases in H₂O₂ generation in a dose related manner compared to IAV alone (** indicates p<0.05 compared with IAV alone). KR-12 caused slight but statistically significant increase in H₂O₂ generation compared with IAV alone. Results are mean ± SEM of 3–5 experiments using separate neutrophil donors.