mRNA Expression and RNA Editing (2451 C-to-U) of IL-12 Receptor β(2) in Adult Atopic Patients

Interleukin (IL)-12 activates T helper (Th) 1 cells to produce interferon (IFN)-γ which inhibits atopic inflammation. IL-12 acts through interaction with its receptor, especially β(2) subunit. In several studies, the low production of IFN-γ in peripheral mononuclear cells of atopic patients on response to IL-12 stimulation has been reported. Therefore we investigated the IL-12 receptor β(2) (IL-12Rβ(2)) mRNA expression and RNA editing, nucleotide 2451 C-to-U conversion, to find the cause of low responsiveness to IL-12 in atopy. Quantitative real time PCR for mRNA expression and sequence analysis for RNA editing were performed in 80 atopic patients and 54 healthy controls. The expression of IL-12Rβ(2) mRNA was significantly lower in atopic patients than healthy controls (p<0.05). In sequence analysis, RNA editing on nucleotide 2451 was not found from either atopic patients or healthy controls. In additional evaluation, there was no relationship between expression of IL-12Rβ(2) mRNA and serum total IgE or blood eosinophil count. Reduced IL-12Rβ(2) mRNA expression in atopic patients indicate the reduced capacity to respond to IL-12 which induce IFN-γ production and this may contribute to Th2-skewed immune response in atopy.