Preparation and characterization of extracelluar region of Interleukin-13 receptor 1 chain and IL-4 receptor

Honjo, Eijiro; Shoyama, Yoshinari; Tamada, Taro; Arima, Kazuhiko*; Kanaji, Sachiko*; Izuhara, Kenji*; Kuroki, Ryota

The receptor binding to Interleukin (IL)-13 is composed of the IL-13 receptor 1 chain (IL-13R1) and the IL-4 receptor chain (IL-4R). In order to investigate the interaction of IL-13 with IL-13R1 and IL-4R, the DNA fragments coding the extracellular regions of human IL-13R1 and the IL-4R, containing a cytokine receptor homologous region, were fused with human Fc and expressed by silkworm-baculovirus system. Size exclusion chromatography did not reveal association between IL-13 and IL-13R1 under these conditions, but the clear association of IL-13 and IL-13R1 was observed after adding IL-4R. This indicates that both extracellular regions of IL-13R1 and IL-4R have functions, and the association between IL-13 and IL-4R increases the IL-13 affinity to IL-13R1.