Treatment of Il1r1-deficient mice with CXCL1 partially increases resistance to Aspergillus fumigatus infection.
C57BL/6 mice and Il1r1-deficient mice were challenged i.t. with 5×107 CEA10 conidia. Three hours post-challenge mice were given 0.5 μg CXCL1 i.t. or PBS alone. Twenty-four hours post-infection, mice were euthanized, BALF collected, and lungs saved for histological analysis. (A) Formalin-fixed lungs were paraffin embedded, sectioned and stained with H&E (top) or GMS (bottom) for analysis by microscopy. Representative lung sections from Il1r1-deficient mice challenged with CEA10 for 48 h and treated with either PBS or CXCL1 are shown using either the 4× (left) or 20× (right) objectives. (B)A. fumigatus germination rates were assessed at 48 h of infection by microscopically counting both the number of conidia and number of germlings in GMS-stained section. Number of conidia and number of germlings were counted for each GMS-stained section to quantify the percent germination. (C) Macrophage and neutrophil recruitment in Il1r1-deficient mice 24 h post-challenge infected with A. fumigatus treated with PBS or CXCL1 given i.t. was determined via cytospins.(D) Bone marrow neutrophils from C57BL/6 and Il1r1-deficient mice were incubated with CEA10 germlings in vitro at a 10:1 ratio in normoxia for 2 h. The XTT assay was used to determine percent fungal damage. (E) Lung damage and (F) leakage were assessed by measuring LDH and albumin, respectively. Data is representative of at least two independent experiments consisting of three to five mice per group, except for the bone marrow neutrophil anti-hyphal XTT assay which is a single experiment which consisted of pooled bone marrow neutrophils from three mice done in triplicate. Each symbol represents an individual mouse or replicate and the line represents the group mean. Statistically significant differences were determined using a one-way ANOVA with Bonferroni’s post-test (*p < 0.05, **p < 0.01, ***p < 0.001, ns = not significant).
