Fig. 1: Respiratory IAV infection alters maternal lung inflammation and circulating cytokines in a dose- and time-dependent manner.
A Experimental schematic. B IAV inoculation at GD9.5 suppressed body weight gain per day from 2-to-7 dpi in X31hi dams only (repeated measures 2-way ANOVA, the main effect of time = p < 0.001; * = Con vs X31hi, & = X31mod vs X31hi, + = Con vs X31mod). C The presence of IAV-X31 in lungs at 2 and 7 dpi was evaluated using qPCR with a cycle threshold of ≤ 30 cycles as confirmed infection (dotted line). D Quantification of H&E pathological scoring showed elevated lung lesion scores in infected dams. The scoring criteria are listed in the methods with additional scoring values in Supplementary Table S3. E Representative photomicrographs of H&E-stained lung sections. Asterisks (*) indicate bronchi filled with clusters of neutrophils with cellular debris, and arrows (→) indicate arterial and venous endothelia with rolling neutrophils. Genes encoding for classic pro-inflammatory cytokines IL-6, IL-1β, and TNF-α in maternal lungs were F upregulated in a dose-dependent manner at 2 dpi whereas G only Il1b was upregulated at 7 dpi. IL-17 genes were upregulated in the maternal lung at H 2 and I 7 dpi in a dose-dependent manner. Maternal cytokines in circulation at J 2 and K 7 dpi. Pro-inflammatory cytokine IL-6 was upregulated in moderate- and high-dose dams proportional to dosage at both time points. IL-17A was not upregulated in circulation at either endpoint. IAV = influenza A virus, GD = gestational day, dpi = days post-inoculation, Con = saline control, X31mod = IAV-X31 103 TCID50, X31hi = IAV-X31 104 TCID50. Groups were compared using one-way ANOVA with Tukey post hoc for multiple comparisons. For data containing residuals with unequal variance, Brown-Forsythe and Welch’s ANOVA with Dunnett T3 post hoc multiple comparisons was used. For non-parametric data, Kruskal–Wallis ANOVA with Dunn’s correction for multiple comparisons was used. Data are means ± SEM; one symbol = p < 0.05, two symbols = p < 0.01, three symbols = p < 0.001; dots represent individual dams; n = 9–14 per treatment group. See Supplementary Tables S3–5 for complete statistical analysis of all data collected for this figure (individual mean ± SEM per group, p-values, hypothesis test used, and test statistic).
