Expression of inflammatory signals involved in neutrophil chemotaxis in the blood and lungs of mice infected i.n. with <i>Y</i>. <i>pestis</i> strains.

<p>C57BL/6 mice were infected i.n. with 1×10⁵ cfu (100 LD₅₀) of the virulent <i>Y</i>. <i>pestis</i> strain Kim53. (A) At the indicated time points post infection, the levels of KC, MIP-2 and G-CSF proteins in the plasma were determined by ELISA. (B) Lung supernatants were extracted from the infected mice at the indicated time points and used for functional Transwell-migration assays with naïve BM-derived neutrophils. (C-E) The levels of KC, MIP-2 and G-CSF protein (blue) and mRNA (red) were determined by ELISA and qPCR analysis in BALF samples and whole lung cells respectively following infection with the virulent <i>Y</i>. <i>pestis</i> strain Kim53. (F-H) C57BL/6 mice were infected i.n. with 1×10⁵ cfu of the avirulent <i>Y</i>. <i>pestis</i> strain Kim53Δ70Δ10 and at the indicated time points post infection the protein (blue) and mRNA (red) levels of KC, MIP-2 and G-CSF were determined. All results are presented as the means ± SEM (*p<0.05, **p<0.01, ***p<0.001). Protein and mRNA levels are presented as fold change relative to naïve mice. n >10 mice per group of at least 3 independent experiments.