點帶石斑之Interleukin-6 receptor (IL-6R) 的基因選殖分析及其與Interleukin-6 (IL-6) 融合蛋白的建構與蛋白表現

Abstract

Interleukin-6 (IL-6) is a pleiotropic cytokine, which has various effects on innate and acquired immune responses including induce the expression of acute phase proteins (APPs), antimicrobial peptides and complements, promoting antimicrobial activities. When it binds with the specific cognate receptor interleukin-6 receptor (IL-6R) and glycoprotein 130 (gp130), it can activate downstream signaling pathway; there are two different binding type between IL-6, IL-6R and gp130 ‘class-signaling pathway’ was lunched by IL-6 binding the receptor IL-6R and gp130 on the cell membrane of target cell; ‘trans-signaling pathway’ require a soluble IL-6R (sIL-6R) instead of mIL-6R on the target cell surface. In order to increase the effect of IL-6 induced trans-signaling pathway, in previous research, designed a recombinant fusion protein by linking an IL-6, a soluble IL-6R and a flexible peptide linker, and named Hyper-IL-6. It has 100 to 1,000-fold more activity than free form IL-6 and IL-6R. Since Hyper-IL-6’s high immune inducible efficiency, it might be a good candidate protein for immunostimulants or adjuvants of vaccine in teleost. In this study, the Epinephelus coioides (grouper) IL-6R was cloned and IL-6R homologues were identified. Then, the protein and specific domain were defined, including immunoglobulin domain (Ig domain), cytokine-binding domains (CBD, IL-6 binding site), fibronectin type III domain (FN 3 domain), WSXWS motif, cysteine residues. Based on the research in 1997, The combination of the extracellular domain of grouper IL-6R and IL-6 together with a peptide linker was constructed. The functional analyzed and binding assay of Hyper-IL-6 will be confirmed in the future work, and hope that can increasing the immunology effectively enhance in aquaculture.