Fig. 7

Platelet-TLR7 solely mediates neutrophil-DNA release through C3. Platelets and neutrophils were isolated from human blood. Each population was pretreated for 15 min with a TLR7 agonist (1 mM Loxoribine, Loxo) and then incubated with the other population for 30 min. All experiments were carried out at an approximately physiological ratio of 50 platelets:1 neutrophil. a Confocal microscopy of the incubated cells. Cells were stained with (CD41-FITC-platelets; CD66b-APC-neutrophils; DAPI-DNA) and visualized with a confocal microscope. b Quantitation of the confocal images in (a), p = 0.017, F = 6.624; df = 2. c DNA release from neutrophils in the presence of platelets pretreated with a C3 inhibitor, compstatin (0.088 mg/mL) for 10 min and then stimulated with Loxo for 30 min (p = 0.0033, F = 11.51, df = 2). d Assessment of neutrophil-DNA release by confocal images of isolated platelets and neutrophils treated with influenza WSN/33 in the presence or absence of the TLR7 inhibitor IRS661. e Quantitation of the confocal images in (d), p < 0.0001; F = 61.07, df = 3. In all cases data in the graphs are represented as the average ± SD. Statistical significance was measured by ANOVA followed by a Bonferroni follow-up test of n = 4 (2F and 2M, with the exception of (e), where we used 3F and 1M), star symbol (*) indicates p < 0.05. Source data for all graphs are provided as a Source Data file