Difference of biological activities and signals between IFN-ζ/limitin and IFN-α

我们鉴定的限制蛋白与I型ifn具有序列同源性，并对几种病毒显示抗病毒活性。此外，它还能与IFN-α/βR结合，诱导IFN-α和IFN-β等效应物。基于这些事实，国际干扰素和细胞因子研究协会的命名委员会认为限制蛋白是一种新型I型干扰素，并将其命名为IFN-ζ。用细胞病变效应染料结合法测定脑心肌炎病毒感染的L929细胞中IFN-ζ/极限蛋白和IFN-α的含量。30 pg/ml的IFN-ζ/限药和30-300 pg/ml的几种亚型IFN-αs可达到半最大保护。这些滴定的干扰素被用于逐点比较它们的生物活性和信号。IFN-ζ/限制蛋白具有与IFN-α一样强的抗肿瘤、免疫调节和抗病毒活性。然而，IFN-ζ/限制蛋白对CFU-GM和BFU-E菌落形成没有抑制作用，而IFN-α有抑制作用。抑制cfu - il - 7和CFU-Meg集落形成需要更多的IFN-α。同样，当注射4000国际单位(IU)/体/天的IFN-α时，骨髓中约30%的CFU-GM和50%的BFU-E减少，而即使注射40000 IU/体/天的IFN-ζ/限时，对这些祖细胞也没有影响。在信号传导方面，IFN-ζ/limit和IFN-α之间使用了类似的信号分子，但存在一些差异。在成纤维细胞中，与IFN-α相比，irf -1依赖通路对IFN-ζ/限制蛋白诱导抗病毒状态和诱导ISRE启动子活性更为关键。此外，与IFN-α相比，在巨核细胞中诱导Daxx需要更高剂量的IFN-ζ/限制性蛋白。我们还分析了Daxx在细胞凋亡中的作用，并确定了DMAP1和TSG101为新的Daxx相关蛋白。如上所述，我们已经澄清了IFN-ζ/限制蛋白在生物活性和信号传导中的特征。遗憾的是，我们无法分离出IFN-ζ/limit的人类同源物。为了制造具有IFN-ζ/限制蛋白部分特征的工程化细胞因子，我们根据IFN-ζ/限制蛋白与IFN-α序列的差异，构建了带有突变的IFN-a cDNA。少

Our identified limitin has a sequence homology with type I IFNs and displays antiviral activity against several viruses. In addition, it can bind to IFN-α/βR and induces some effectors as IFN-α and IFN-β. Based on these facts, limitin has been considered as a novel type I IFN with the designation of IFN-ζ by the Nomenclature Committee of the International Society for Interferon and Cytokine Research. Both IFN-ζ/limitin and IFN-α were titrated with a cytopathic effect dye binding assay in encephalo myocarditis virus-infected L929 cells. Half-maximal protection was achieved with 30 pg/ml of IFN-ζ/limitin and with 30-300 pg/ml of several subtypes of IFN-αs. These titrated IFNs were used for point-by-point comparison of their biological activities and signals. IFN-ζ/limitin showed antitumor, immunomodulatory, and antiviral activities as strong as IFN-α. However, IFN-ζ/limitin did not suppress CFU-GM or BFU-E colony formation while IFN-α did. Much higher concentrations of IFN-ζ/limitin than … More IFN-α were required for the suppression of CFU-IL7 and CFU-Meg colony formation. Similarly, approximately 30% of CFU-GM and 50% of BFU-E in bone marrow were reduced when 4,000 international unit (IU)/body/day of IFN-α was injected, while there was no influence on these progenitors even when IFN-ζ/limitin was injected at 40,000 IU/body/day. With regard to signaling, similar signaling molecules are used between IFN-ζ/limitin and IFN-α, but there are some differences. In fibroblasts, IRF-1-dependent pathway is more critical for IFN-ζ/limitin than IFN-α to induce antiviral state and to induce ISRE promoter activity. In addition, higher dose of IFN-ζ/limitin is required for the induction of Daxx in megakaryocytes than IFN-α. We also analyzed a role of Daxx in apoptosis, in addition, identified DMAP1 and TSG101 as novel Daxx-associated proteins. As described above, we have clarified characters of IFN-ζ/limitin in biological activities and signaling. To our regret, we could not isolate the human homologue of IFN-ζ/limitin. To make an engineered cytokine with some features of IFN-ζ/limitin, we have constructed IFN-a cDNA with mutations based on the differences of sequence between IFN-ζ/limitin and IFN-α. Less