Association study between interleukin-12 receptor β1/β2 genes and type 1 diabetes or asthma in the Japanese population

Interleukin-12 (IL-12) secreted from macrophages or dendritic cells plays an important role in the protection against intracellular pathogens as well as the developmental commitment of T helper 1 cells. IL-12 exerts its biological effects through binding to specific IL-12 receptors (IL-12Rs) termed IL-12Rβ1 and IL 12Rβ2. In this paper, we performed association studies between the three reported polymorphisms (Q214R, M365T and G378R) of the IL-12Rβ1 gene or the newly identified polymorphisms (P238L, IVS9 −7G>A, IVS13 –121G>A, A643T, P779P and c.3283T>G) of the IL-12Rβ2 gene, and the development of type 1 diabetes or atopic asthma as representative Th1- and Th2- dominant diseases, respectively. The association study of each polymorphism of the IL-12Rβ1 or IL-12Rβ2 gene and type 1 diabetes or asthma showed that these IL-12R genes did not contribute to the development of type 1 diabetes or asthma in the Japanese population. Further analysis in individuals with susceptibility to intracellular pathogens may elucidate the importance of the IL-12R genes.