The effect of LERD on the expression and secretion of TNF-α and IL-4. (A) The IgE-primed RBL-2H3 cells (1 × 106 cells/well) were stimulated by the antigen for 15 min for the assay of TNF-α and IL-4 mRNA by RT-PCR. The representative images (upper panel) and densitometric data (lower panel) from three independent experiments are shown. (B) The IgE-primed RBL-2H3 cells (1 × 106 cells/well) were stimulated by antigen for 8 h and the secretion of TNF-α and IL-4 was then measured by ELISA. The values are expressed as the mean ± SEM from three independent experiments. Asterisks indicate significant differences from the controls, *P < 0.05 and **P < 0.01. PP2 is a general Src family kinase inhibitor.