Fig. 6: Knock out Il1r2 alleviates intrauterine growth restriction caused by respiratory influenza virus infection.

a Schematic diagram illustrating the mating strategy and timing of infection in pregnant Il1r2^+/+ and Il1r2^−/− mice (Created in BioRender. Ding, X. (2026) https://BioRender.com/lfokc6w). b–j Maternal lungs and deciduas were collected at embryonic day 12.5 (E12.5) for analysis. b, c Representative images of lungs from pregnant Il1r2^+/+ (n = 4 for Saline and n = 3 for H1N1) and Il1r2^−/− (n = 3 for Saline and n = 5 for H1N1) mice (b) and the ratio of lung tissue mass to mouse body weight (c). scale bar, 1 cm. The red arrow marks the parenchymal lung lesion. d, e Representative images of hematoxylin and eosin (H&E) staining of lung sections (d) and inflammation score for lung sections (e) from pregnant Il1r2^+/+ and Il1r2^−/− mice infected with either saline or H1N1. scale bar, 50 μm. f, g Representative images of the uterus, fetuses, and placentas (f) and statistical analysis of the length and weight of fetuses and the diameter and weight of placentas from pregnant Il1r2^+/+ (n = 36 for length of fetuses, n = 36 for weight of fetuses, n = 38 for diameter of placentas, and n = 37 for weight of placentas for Saline, and n = 36 for length of fetuses, n = 36 for weight of fetuses, n = 37 for diameter of placentas, and n = 37 for weight of placentas for H1N1) and Il1r2^−/− (n = 30 for length of fetuses, n = 30 for weight of fetuses, n = 30 for diameter of placentas, and n = 30 for weight of placentas for Saline, and n = 34 for length of fetuses, n = 34 for weight of fetuses, n = 34 for diameter of placentas, and n = 32 for weight of placentas for H1N1) mice (g). scale bar, 1 cm. h, i Representative images of H&E staining of vessels in decidua sections (h) and statistical analysis of vessel thickness (i) from pregnant Il1r2^+/+ (n = 16 for Saline and n = 30 for H1N1) and Il1r2^−/− (n = 20 for Saline and n = 6 for H1N1) mice. scale bar, 50 μm. j Representative images of immunohistochemistry staining of Cytokeratin in decidua sections from pregnant Il1r2^+/+ and Il1r2^−/− mice infected with either saline or H1N1. scale bar, 50 μm. The red line indicates the boundary between the maternal and fetal sides. The red star marks the site of trophoblast invasion into the decidua. M maternal, F fetal. Results are representative of two or three independent experiments. All bars in the graphs represent the mean ± s.e.m. Statistical comparisons were performed using one-way ANOVA with Tukey’s multiple comparisons test (c, e, g, i). Source data are provided as a Source Data file.