Upregulated expression and extracellular release of Galectin-3 in lungs during respiratory <i>F. novicida</i> infection.

<p>(<b>A</b>) Total RNA was extracted by Trizol method from lungs harvested at the indicated times after infection with the Wild-type bacteria (WT) or from mice vaccinated with an attenuated mutant strain followed by challenge with WT bacteria (Mut/WT mice). The mRNA levels of Galectin-3 were analyzed by real-time PCR as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0059616#s2" target="_blank">Materials and Methods</a> and are expressed as fold changes over the levels in mock control mice. Data shown are the averages of 3–4 mice per group. Statistically significant differences are denoted by asterisks (**p<0.005). (<b>B</b>) In-situ IF staining of frozen lung sections from mock infected and WT U112 infected or Mut/WT mice harvested at 3 d. p.i Lung harvested 3 weeks after vaccination with the mutant alone (Mut-3 wk) served as controls for Mut/WT mice. The sections were stained for galectin-3 (red) using a purified rat anti-mouse galectin-3 antibody followed by Alexa-546 conjugated chicken anti-rat antibody. Nuclei (blue) were stained with 4′6′ diamidino-2-phenylindol-dilactate (DAPI). Magnification×200. Insets depict extracellular galectin-3 in WT <i>F. novicida</i> infected mouse lungs (B2’) and cytosolic galectin-3 in Mut/WT (B4’) mouse lungs.