9:30 AM - 9:40 AM
[O3-D-AM1-07] The function of interleukin-1 receptor type 2
Keywords:IL-1R2、シグナル伝達、デコイ受容体
IL-1R2 is known as a decoy receptor that can bind to its ligand, IL-1, but cannot signal because it does not have a Toll/IL-1 receptor (TIR) domain in the cytoplasm. Therefore, IL-1R2 is regarded as a molecule that suppresses the immune response induced by IL-1. However, the function of IL-1R2 is exhibited only in specific cells such as macrophages, and its mechanism of action has not been fully elucidated. In this study, we focused on the intracellular function of IL-1R2 and aimed to elucidate its function. Human uterine cancer-derived cultured cells HeLa and human oral squamous cell carcinoma-derived cultured cells HSC3 were used in the experiment. Expression vectors for various deletion mutants of IL-1R2 were constructed and transfected together with the IL-1α expression vector. The expression of IL-1R2 and IL-1α was detected by immunofluorescence staining and western blot, and the efficiency of IL-1α secretion was examined using an ELISA kit. IL-1R2 knockdown in HSC3 used shRNA. When the IL-1α secretion level of the IL-1α transfectant was taken as 100%, the co-transfectant with wild type IL-1R2 reduced the IL-1α secretion level to 47.0 ± 0.2%. On the other hand, the mutant lacking the transmembrane domain and the cytoplasmic domain did not suppress secretion. This tendency was also observed in mutants lacking the nuclear localization signal for IL-1α. On the other hand, reduction of IL-1R2 expression in HSC3 by shRNA did not enhance IL-1α secretion. These findings suggest that IL-1R2 acts to suppress the extracellular secretion of IL-1α, and that the transmembrane domain is important for this function.