25% by day 5. As shown previously [3], weight loss in the infected C57BL/6J mice was less pronounced,

as reflected in a mere 5 – 10% reduction by day 4 – 5. In both strains, statistically significant differences LY2874455 datasheet between infected and mock treated mice were observed by day 3. Mock-treated mice showed no significant weight loss at any time point. Thus, there was no significant effect of the anesthesia/infection procedure on body weight in either mouse strain. Figure GDC941 1 Weight loss and expression of IAV HA mRNA throughout the 5-day time course after mock treatment or infection with IAV strain PR8_MUN as outlined in the Methods section. A. Weight loss, expressed as the percentage of body weight measured at t = 0 h before administration of anesthesia. No mice had to be killed because of >30% weight loss. B.

Relative quantification of IAV HA mRNA in mouse lung by qRT-PCR in the 5-day time course shown in panel A. dCt refers to Ctreference – Cttarget mRNA, where Ctreference corresponds to the arithmetic mean of the Ct values of Actb and Rpl4. Solid lines, infection; interrupted lines, mock treatment. Left panels, DBA/2J strain; right panels, C57BL/6J strain. Note that the x-axes of the panels are based on different scales. *, p ≤0.05 for difference with respect to t = 0 h; ‡, p ≤0.05 for difference between

mock-treated and infected mice at the given time point (Tukey’s test). Viral Mizoribine mouse replication qRT-PCR revealed a brisk rise of mRNA encoding IAV HA in lungs of both mouse strains after infection (Figure 1B). HA mRNA was detected at low levels as early as 6 h in both strains, followed by a rapid rise that peaked at 48 h and 120 h in DBA/2J and C57BL/6J mice, respectively. HA mRNA levels were significantly higher in DBA/2J than in C57BL/6J selleckchem starting around 12 h. As expected, HA mRNA was not detected in the mock treated mice. Principle component analysis of pulmonary expression of host-encoded mRNAs A cluster containing infected and mock treated time points could be identified easily in both mouse strains (Figure 2). A separation between infected and mock-treated samples became evident at 18 h in both mouse strains, as indicated by the lines in Figure 2. Marked step-offs between 24 and 48 h were seen in both strains. Consistent with the continuing rise of HA mRNA in the C57BL/B6 strain between 48 and 120 h the 120 h time point localized beyond the 48 h time point. In contrast, in the DBA/2J strain HA mRNA declined between 48 and 120 h, and the 120 h time point localized between 24 and 48 h in the PCA plot. In both strains, the t = 48 h and 120 h mock treated mice localized far away from the infected t = 48 and 120 h mice.