Vitamin A deficiency impairs <i>S. mansoni</i>-elicited Th2 responses.

<p>(<b>A</b>) Quantification of <i>S. mansoni</i> eggs deposited per gram of liver. (<b>B–D</b>) Histopathology of liver tissue sections stained with hemotoxylin and eosin and evaluated for granuloma volume (B), eosinophil infiltration (C), and microvesicular liver damage (D). (<b>E</b>) Flow cytometric analysis of intracellular cytokines expressed by cells harvested from the liver and colon following a 5-hour stimulation with PMA and ionomycin in the presence of brefeldin A. Representative contour plots are gated on live CD4⁺ T cells. n = 3–5 mice per group. (<b>F</b>) Cytometric bead array analysis of cytokine concentrations in culture supernatants. 3×10⁵ hepatic leukocytes harvested from <i>S. mansoni</i>-infected (Inf) and control (Cont) mice were cultured for 72 hours in the presence of egg homogenate (50 µg/mL), adult worm homogenate (50 µg/mL), or media alone. n = 3–4 mice per group. (<b>G</b>) qRT-PCR analysis of cytokine expression in hepatic leukocytes. Expression is normalized to HPRT. n = 3–5 mice per group. Error bars illustrate SEM; *p<0.05, **p<0.01, #p<0.001. <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002883#s2" target="_blank">Results</a> are representative of two (A–D) or three (E, G) independent experiments.