Fig. 1: Human PMNs take up and respond to RNA when complexed to LL37.

a–c IL-8 release (ELISA, 4 h stimulation) and CD62L shedding (flow cytometry, 1 or 2 h) by PMNs from healthy donors stimulated with LPS, R848 or CpG ODN (a, n = 6–7), ssDNA and genomic DNA (b, n = 5), or RNA40 (c, n = 8–15), with or without LL37. d Electron microscopy of PMNs incubated with RNA-LL37 for 20 min (n = 2). e–h FACS (e, n = 6), ImageStream cytometry images (f) and quantification (g, scale bar = 10 μm) or conventional bright-field microscopy (h, n = 2, scale bar = 10 μm) of PMNs incubated for 60 min with RNA-AF647 complexed with LL37 (n = 6). In (f) five selected cells from one representative donor are shown, in (g) the % of cells with ‘internalized’ features (n = 2, see Methods). In H unmodified LL37 was replaced with Atto488-labeled LL37, one representative donor shown. i as in (c) but including chloroquine (CQ) pre-incubation for 30 min (n = 6–7). j, k as in c but using total human RNA from HEK293T cells (j, n = 4–6) or bacterial RNA isolated from S. aureus (K, n = 4) with and without LL37. a–c, e, f, i–k represent combined data (mean + SD) from ‘n’ biological replicates (each dot represents one donor). In d, f, and h representatives of ‘n’ biological replicates (donors) is shown (mean + SD). *p < 0.05 according to one-way ANOVA with Dunnett’s correction (a, b, c, i, j) or Friedman test with Dunn’s correction (e, k). Source data is provided as a Source data file.