Figure 1. Vitamin A deficiency impairs S. mansoni-elicited Th2 responses.

(A) Quantification of S. mansoni eggs deposited per gram of liver. (B–D) Histopathology of liver tissue sections stained with hemotoxylin and eosin and evaluated for granuloma volume (B), eosinophil infiltration (C), and microvesicular liver damage (D). (E) 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. (F) Cytometric bead array analysis of cytokine concentrations in culture supernatants. 3×10⁵ hepatic leukocytes harvested from S. mansoni-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. (G) 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. Results are representative of two (A–D) or three (E, G) independent experiments.