Orlando S, Polentarutti N, Mantovani A
Department of Immunology and Cell Biology, Istituto di Ricerche Farmacologiche 'Mario Negri', Milano, Italy.
Cytokine. 2000 Jul;12(7):1001-6. doi: 10.1006/cyto.1999.0601.
The type II IL-1 receptor (IL-1RII) is a non-signalling molecule which acts as a decoy target for IL-1. Various signals (e.g. chemoattractants and phorbol ester) induce metalloprotease-mediated rapid shedding of the IL-1RII. The present study was designed to compare the susceptibility to shedding of the decoy IL-1RII vs the signalling IL-1RI. HEK 293 cells and COS cells were transfected with cDNAs encoding the human IL-1RI, IL-1RII or both. Slow spontaneous release and rapid phorbol ester-induced shedding were only observed for the decoy IL-1RII. Similarly, OVCAR-3 cells, which express substantial amounts of both IL-1RI and IL-1RII, only released the IL-1RII. These results indicate that the IL-RII, but not the IL-1RI, is susceptible to proteolytic shedding, a finding consistent with the decoy function of this molecule.
II型白细胞介素-1受体（IL-1RII）是一种无信号传导功能的分子，可作为白细胞介素-1的诱饵靶点。多种信号（如趋化因子和佛波酯）可诱导金属蛋白酶介导的IL-1RII快速脱落。本研究旨在比较诱饵性IL-1RII与信号传导性IL-1RI对脱落的敏感性。将编码人IL-1RI、IL-1RII或两者的cDNA转染到人胚肾293细胞和COS细胞中。仅在诱饵性IL-1RII中观察到缓慢的自发释放和佛波酯诱导的快速脱落。同样，大量表达IL-1RI和IL-1RII的OVCAR-3细胞仅释放IL-1RII。这些结果表明，IL-1RII而非IL-1RI易受蛋白水解脱落的影响，这一发现与该分子的诱饵功能一致。
