Seleno-L-methionine suppresses immunoglobulin E-mediated allergic response in RBL-2H3 cells.

The effect of seleno-L-methionine (SeMet) on immunoglobulin (Ig) E-mediated allergic responses were investigated using rat basophilic leukemia RBL-2H3 cells. Cells were first treated with or without SeMet, sensitized with anti-dinitrophenyl IgE and stimulated with the antigen dinitrophenyl-human serum albumin, before the measurement of degranulation, calcium mobilization, mRNA expression and protein secretion of interleukin (IL)-4 and tumor necrosis factor (TNF)-alpha, and phosphorylation of spleen tyrosine kinase (Syk), Akt, and mitogen-activated protein kinases (MAPKs). The antigen-induced beta-hexosaminidase release, a degranulation marker, was significantly inhibited by SeMet treatment. SeMet also significantly suppressed antigen-induced calcium mobilization. Antigen-induced increases in the mRNA expression and protein secretion of IL-4 and TNF-alpha were both significantly attenuated by SeMet treatment. In addition, SeMet significantly suppressed antigen-induced phosphorylation of Syk, Akt, and MAPKs. These results demonstrate that SeMet suppresses antigen-induced degranulation, and mRNA expression and protein secretion of IL-4 and TNF-alpha, and inhibits antigen-induced mobilization of calcium and activation of Syk, Akt, and MAPKs. Our study provides valuable information that may be useful in the prevention and treatment of allergic diseases.