Expression and purification of extracellular region of interleukin-13 receptor 1 chain and its interaction with its ligand

Kuroki, Ryota; Honjo, Eijiro; Tamada, Taro; Arima, Kazuhiko*; Izuhara, Kenji*

Interleukin-13 (IL-13) interacts with two types of receptors, the IL-13R1 chain (IL-13R1) and the IL-4R chain (IL-4R), that transduce the IL-13 signals. In order to investigate the interaction of IL-13 with IL-13R1 and IL-4R, the genes coding the extracellular regions of human IL-13R1 and the IL-4R containing cytokine receptor homologous region (CRH), were fused with human Fc, and expressed by silk worm. After further purification with anion-exchange chromatography, the receptors were used to investigate the ligand-receptor interaction. The size exclusion chromatography showed that association between IL-13 and IL-13Ra1 could not be observed in this condition whereas the clear association of IL-13 and IL-13Ra1 was observed after adding IL-4R. It indicates that the association between IL-13 and IL-4R increase the IL-13 affinity to IL-13R1.