Figure 3.

Chemokine C‐X‐C ligand 4 motif (CXCL4) in complex with human nucleic acids of various origin stimulates interferon (IFN)‐α release by platelet dendritic cells (pDCs). (a) Purified pDCs (175 × 10³/ml) from five different healthy donor (HD) peripheral blood mononuclear cells (PBMCs) were treated with CXCL4 alone (1 μM), human RNA alone (huRNA, 20 μg/ml) or CXCL4 pre‐complexed with huRNA (at the same concentrations), overnight. The release of IFN‐α in the culture supernatants was tested by enzyme‐linked immunosorbent assay (ELISA), as described 29. (b) PDCs (175 × 10³/ml) from seven different HD PBMCs were stimulated overnight with CXCL4 alone (1 μM), human DNA alone (huDNA, 10 μg/ml), mitochondrial DNA (mitoDNA, 10 μg/ml) or CXCL4 precomplexed with the two DNA types. IFN‐α in the culture supernatants was tested by ELISA. Horizontal bars are the means, vertical bars are standard errors of the mean, P‐values by Wilcoxon’s signed‐rank test.