5 [13] cat.code: mab-mtrl2, InVivoGen, San Diego, USA) at the concentration 100 ng/ml for 1 h. The cells were then infected with P. acnes as described above. Supernatants were harvested after 24 h and 48 h. Supernatants were cleared from particles by centrifugation 10 min at 12000 g, stored at -20C and later assayed for IL-6, IL-8 and GM-CSF by ELISA (R&D systems, Minneapolis, Minnesota) according to manufacturer’s instruction. RNA preparation and Reverse Transcription PCR Cells were seeded at a density of 1 × 106 in a 25 cm2 culture flask in normal growth medium. After 48 h, cells were washed in PBS and the medium were changed to DMEM without FCS and PEST. Cells were infected

with P. acnes at a MOI of 16:1 and immediate close contact between bacteria and cells were achieved by centrifugation of the flask for 10 min at 700 g. Total RNA was prepared after learn more 0 h and 24 h using RNeasy Mini kit (Qiagen, Hilden, Germany) with the on-column DNase treatment step according to manufacturer’s instruction. Cells were trypsinised using 0,05% MK-8931 nmr (w/v) trypsin/EDTA, lysed in 350 μl RTL buffer and homogenized in a TissueLyser with Stainless steel Beads, 5 mm (Qiagen, Hilden, Germany). RNA concentration and purity were assessed in a NanoDrop© ND-1000 spectrophotometer (Thermo scientific,

Wilmington, USA) at A260 and the ratios of A260:A230 and A260:280. Complementary DNA (cDNA) was generated from one μg total RNA using RT2 First strand kit (SABiosciences, Frederick, MD, USA) according to the manufacturer’s instruction. Quality of the cDNA was verified by PCR array housekeeping genes: beta-2-microglobulin, hypoxanthine phosphoribosyltransferase 1, ribosomal protein L13a, glyceraldehyde-3-phosphate

dehydrogenase, beta-actin using primers from (SABiosciences, CYTH4 Frederick, MD, USA). Real-time BI 2536 nmr Quantitative PCR Gene expression analysis measuring transcription of 84 inflammation associated genes was conducted using the RT2 Profiler PCR Array, Human Toll-Like Receptor Signaling Pathway PAHS-018A (SABiosciences, Frederick, MD, USA) according to manufacturer’s instruction. Real-time PCR detection was performed with an IQ™5 instrument (Bio-Rad, Hercules, CA, USA). Complete list of genes analyzed by the array can be found at: http://​www.​SABiosciences.​com Data Analysis Relative gene expression was calculated with the ΔΔCt method in the web-based software package for RT2 Profiler PCR array systems (SABiosciences, Frederick, MD, USA). Statistical Methods Due to the small sample size (n = 3), a permutation test was used to test possible regulation [38]. A null hypothesis corresponding to no regulation was tested for each gene and each protein concentration and rejected for p = 0.05. Acknowledgements Grant sponsor: Kempestiftelserna (OA, FE, JO); Grant sponsor: Lions Cancer Research Foundation and Cancerforskningsfonden Norrland (JO).