Figure 1.

Citrullination of LL-37 abrogates the antiviral activity of the peptide toward human rhinovirus. Purified HRV1B viral particles were pre-treated with 10 μg (A) or 30 μg (B) of native or differentially citrullinated LL-37 peptides (Table 1) for 2 h before incubation with 16HBE14°− cells for 1 h at a final MOI of 1. Cells were washed to remove inoculum and incubated for 24 h before viral RNA in cells was addressed by qPCR. To measure released viral particles, cell supernatants from (B) were serially diluted and exposed to WI-38 cells to obtain an infectious viral titer (TCID₅₀/ml) (C). S. aureus bacteria was treated directly with 30 μg/ml of the native and modified LL-37 peptides for 2 h and incubated for 24 h before enumeration of colony formation units (CFU/ml) (D). Data represent mean values ± SEM for n = 3 experiments for each condition *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. Statistical analysis performed by one-way ANOVA with Dunnet multiple comparisons test.