<i>Il1r1</i>-deficient mice are highly susceptible to <i>Aspergillus fumigatus</i> infection.

<p>Age-matched C57BL/6 or <i>Il1r1</i>-deficient mice were infected i.t. with 5×10⁷ CEA10 conidia and at indicated time-points, mice were euthanized, BALF collected, and lungs saved for histological analysis. <b>(A)</b> Formalin-fixed lungs were paraffin embedded, sectioned, and stained with H&E (top) or GMS (bottom) for analysis by microscopy. Representative lung sections from C57BL/6 and <i>Il1r1</i>-deficient mice infected with CEA10 for 48 h are shown using either the 4× (left) or 20× (right) objectives. <b>(B)</b><i>A. fumigatus</i> germination rates were assessed over the first 72 h of infection by microscopically counting both the number of conidia and number of germlings in GMS-stained section. <b>(C)</b> Survival of C57BL/6, <i>Pycard</i>^−/−, and <i>Il1r1^−/−</i> mice challenged i.t. with 1.5×10⁷<i>A. fumigatus</i> (CEA10) conidia was then monitored for survival over the first 96 h (Mantel-Cox log-rank test, p = 0.0002). Data are representative of 2 independent experiments at each time point consisting of at least 5 mice per group. <b>(D)</b> Total macrophage (left panel) and neutrophil (right panel) recruitment in the BALF was measured at 12, 24, and 48 h post-infection. Data are representative of at least 2 independent experiments at each time point consisting of 3–5 mice per group. Bar graphs show the group mean ± one SEM. Statistically significant differences were determined using Student’s t-test (*p < 0.05; **p < 0.01).