After transfer into a new tube containing 2 ml RNAlater, lungs were stored overnight at 4°C and then at -20°C until further use. All animal work was approved see more by an external committee according to the regulations on animal welfare of the Federal Republic of Germany. RNA isolation and qRT-PCR Lungs were homogenized in 4 ml RLT buffer (Qiagen) containing 40 μl β-mercaptoethanol and stored at -80°C in 450 μl aliquots. After thawing, 450 μl of this suspension was mixed with 700 μl Qiazol (Qiagen), and all further steps of total RNA isolation were performed with the miRNeasy kit (Qiagen) according to the manufacturer’s

recommendations. Real-time RT-PCR (qRT-PCR) was performed with a LightCycler 480 (La Roche AG, Basel, Switzerland) in 96 well plates in 20 μl reaction volumes, using 15 ng cDNA (miScript Reverse Transcription Kit, QuantiTect SYBR Green PCR Kit) and primers specific for the following targets: the immediate early gene FBJ osteoscarcoma oncogene (Fos), resistin like α (Retnla), immune-responsive gene 1 (Irg1), interleukin 6 (Il6), interleukin 1β (Il1b), the chemokine (C-X-C motif) ligand 10 (Cxcl10), four genes related to interferon pathways (the transcription factor

signal transducer and selleck kinase inhibitor activator of transcription 1 (Stat1), interferon γ (Ifng), interferon λ2 (Ifnl2, aka Il28a), and myxovirus (influenza virus) resistance 1 (Mx1)), and IAV hemagglutinin (HA). Quantitect Tyrosine-protein kinase BLK Primer Assays (Qiagen) were used for all targets except Ifnl2 and HA. Primers for amplification of Ifnl2 were designed using exon-spanning regions of the NCBI [4] sequence (Tanta_Mus_Ifnl2-F: 5’ctgcttgagaaggacctgagg’3, Tanta_Mus_Ifnl2-R: 5’ctcagtgtatgaagaggctggc’3). Primer sequences for HA mRNA amplification were published previously [3]. Mouse Genome Informatics (MGI) gene symbols and names were used for all genes [5]. The arithmetic mean of the Ct values of β actin (Actb) and ribosomal protein L4 (Rpl4) was used as internal

reference for normalization. Data analysis Data were analyzed using the R environment and programming code [6]. qRT-PCR data points with Ct ≥40, corresponding to lack of detection of a target due to technical failure or lack of expression, were assigned a Ct of 40. We removed technical outliers in ΔCt values using the maximum normed residual test (Grubbs’ test) to detect outliers for each condition with a threshold of p ≤0.05. A GSK3326595 median of 5 (range, 3–8) biological replicates were available for each data point after outlier removal. ANOVA was used for testing of trends throughout time series, adjusting p values for false discovery rate (FDR). For pairwise comparisons, we used Tukey’s Honest Significant Differences Test for homogeneous variances and Dunnett’s Modified Tukey-Kramer Pairwise Multiple Comparison Test for heterogeneous variances (Levene’s test for variance equality). We used a significance threshold of p ≤0.05.