Changes in Th1 and Th2 cytokine concentrations in ileal Peyer's patches in gilts exposed to zearalenone.

GALT induces tolerance to foreign food antigens and plays an important role in the development of food allergies and the inflammatory bowel disease. The immune function of GALT is significantly influenced by an equilibrium between Th1 and Th2 subpopulations and the cytokines they produce. Th1 cytokines participate in the induction of a cell-mediated immune response, whereas Th2 cytokines induce powerful antibody-mediated responses. Changes in Th1/Th2 cell polarization of an immune response are associated with susceptibility to autoimmune and infectious diseases. This experiment investigated changes in cytokine levels produced by Th1 and Th2 cells in ileal Payer's patches in gilts exposed to ZEN doses below the NOEL (approximately 8 microg kg(-1) BW) for 14, 28 and 42 days. A significant linear increase in IL-4 (40.32 +/- 1.55 ng mg(-1)--137.60 +/- 29.96 ng mg(-1)), and IL-10 (5.99 +/- 0.15 ng mg(-1)--16.39 +/- 1.11 ng mg(-1)) concentrations was observed. An increase in Th1 (IL-2 and IFN-gamma) cytokine levels was also noted in the experimental group, but it was not statistically significant. An HPLC analysis of Peyer's patches in group E animals revealed a linear increase in ZEN concentrations (3.65 +/- 0.91 ng g(-1)--4.72 +/- 1.85 ng g(-1)) and an absence of alpha-ZEL. IL-4 stimulates monocytes and macrophages, it induces the production of proinflammatory cytokines and it may directly and indirectly contribute to the development of inflammatory foci. Higher IL-4 levels could shift polarization toward Th2 cells, stimulate B cells to undergo class switching to produce IgE and contribute to the development of allergies.