Dissing-Olesen Lasse, Thaysen-Andersen Morten, Meldgaard Michael, Højrup Peter, Finsen Bente
Medical Biotechnology Center, University of Southern Denmark, Winsløwparken 25, 2, DK-5000 Odense C, Denmark.
J Pharmacol Exp Ther. 2008 Jul;326(1):338-47. doi: 10.1124/jpet.108.138263. Epub 2008 Apr 29.
Recombinant human interferon-beta (rhIFN-beta) is the leading therapeutic intervention shown to change the cause of relapsing-remitting multiple sclerosis, and both a nonglycosylated and a significantly more active glycosylated variant of rhIFN-beta are used in treatment. This study investigates the function of the rhIFN-beta1a glycan moiety and its individual carbohydrate residues, using the myxovirus resistance (Mx) mRNA as a biomarker in Mx-congenic mice. We showed that the Mx mRNA level in blood leukocytes peaked 3 h after s.c. administration of rhIFN-beta1a. In addition, a clear dose-response relationship was confirmed, and the Mx response was shown to be receptor-mediated. Using specific glycosidases, different glycosylation analogs of rhIFN-beta1a were obtained, and their activities were determined. The glycosylated rhIFN-beta1a showed significantly higher activity than its deglycosylated counterpart, due to a protein stabilization/solubilization effect of the glycan. It is interesting to note that the terminating sialic acids were essential for these effects. Conclusively, the structure/bioactivity relationship of rhIFN-beta1a was determined in vivo, and it provided a novel insight into the role of the rhIFN-beta1a glycan and its carbohydrate residues. The possibilities of improving the pharmacological properties of rhIFN-beta1a using glycoengineering are discussed.
重组人干扰素-β（rhIFN-β）是已被证明能改变复发缓解型多发性硬化症病因的主要治疗手段，治疗中使用了rhIFN-β的非糖基化变体和活性明显更高的糖基化变体。本研究利用黏液病毒抗性（Mx）mRNA作为Mx基因同源小鼠的生物标志物，研究了rhIFN-β1a聚糖部分及其单个碳水化合物残基的功能。我们发现，皮下注射rhIFN-β1a后3小时，血液白细胞中的Mx mRNA水平达到峰值。此外，证实了明显的剂量反应关系，且Mx反应显示为受体介导。使用特定糖苷酶获得了rhIFN-β1a的不同糖基化类似物，并测定了它们的活性。由于聚糖的蛋白质稳定/溶解作用，糖基化的rhIFN-β1a显示出比其去糖基化对应物显著更高的活性。值得注意的是，末端唾液酸对这些效应至关重要。最终，在体内确定了rhIFN-β1a的结构/生物活性关系，这为rhIFN-β1a聚糖及其碳水化合物残基的作用提供了新的见解。讨论了利用糖基工程改善rhIFN-β1a药理特性的可能性。
