Separation of monocytes was conducted within 60 min after blood collection and RNA was extracted the same day. Total RNA was isolated from monocytes using Trizol extraction and purification by silica-based columns. To separate monocytes, 8 mL blood was collected using the Vacutainer CPT Cell Preparation Tube System (BD, Heidelberg, Germany) and 400 µL Rosette Sep Monocyte Enrichment Cocktail (StemCell Technologies, Vancouver, Canada) was added immediately after blood collection. Monocytes, not labeled by antibodies, are collected as a highly enriched fraction at the interface between plasma and the density medium in the tube. After separation, cells were washed twice in ice cold PBS buffer containing 2 mM EDTA. Success of monocyte separation was controlled using an ADVIA 2120 Analyser (Siemens Healthcare Diagnostics, Eschborn, Germany) for part of the samples.
