Fukazawa Y, Kagaya K, Miura H, Shinoda T, Natori K, Yamazaki S
Microbiol Immunol. 1984;28(6):691-702. doi: 10.1111/j.1348-0421.1984.tb00723.x.
During the course of an investigation designed to separate macrophage activating factor (MAF) activity from interferon (IFN) antiviral activity in the lymphokine-rich fraction (LKF) produced by stimulation of murine splenic cells with concanavalin A (Con A), we found molecular evidence for the similarity of the two activities. MAF activity was expressed as the rate of inhibition of intracellular growth of Salmonella typhimurium in macrophages based on the linear correlation between relative MAF activity and LKF concentration. The antiviral substance in LKF was identified as IFN-gamma based on the observation that its activity was inactivated at pH 2 and neutralized with anti-mouse IFN-gamma serum but not with anti-mouse IFN-alpha/beta serum. MAF and IFN antiviral activities displayed identical sensitivity to pH 2 and temperature. Further, neither activity was affected by beta-mercaptoethanol, but both were inactivated by guanidine hydrochloride and by sodium dodecyl sulfate, suggesting that the structures related to conformation of the protein of the two molecules may be similar. In affinity chromatography of the LKF on a Con A-Sepharose column, MAF and IFN activities were found in both the nonadsorbing (F I) and adsorbing (F II) fractions. However, the rates of F II of MAF and IFN activities increased proportionally when the sample was applied on a column of higher capacity, suggesting that the molecular structure of the mannose-containing glycosyl moiety of the two molecules may also be similar. Moreover, the intact or modified form of MAF and IFN activities of different LKF preparations showed a strong correlation, indicating that the production and denaturation of MAF activity were proportional to those of IFN antiviral activity. The results of this study provide strong evidence that MAF and IFN antiviral activities may reside in virtually the same molecular species.
在一项旨在从用伴刀豆球蛋白A（Con A）刺激小鼠脾细胞产生的富含淋巴因子的组分（LKF）中分离巨噬细胞活化因子（MAF）活性和干扰素（IFN）抗病毒活性的研究过程中，我们发现了这两种活性相似的分子证据。MAF活性以基于相对MAF活性与LKF浓度之间的线性相关性的巨噬细胞中鼠伤寒沙门氏菌细胞内生长的抑制率来表示。LKF中的抗病毒物质被鉴定为IFN-γ，这是基于其活性在pH 2时失活且能用抗小鼠IFN-γ血清中和但不能用抗小鼠IFN-α/β血清中和这一观察结果。MAF和IFN抗病毒活性对pH 2和温度表现出相同的敏感性。此外，两种活性均不受β-巯基乙醇影响，但都被盐酸胍和十二烷基硫酸钠灭活，这表明与这两种分子蛋白质构象相关的结构可能相似。在用Con A-琼脂糖柱对LKF进行亲和层析时，在非吸附（F I）和吸附（F II）组分中均发现了MAF和IFN活性。然而，当将样品应用于更高容量的柱上时，MAF和IFN活性的F II比例增加，这表明这两种分子含甘露糖的糖基部分的分子结构也可能相似。此外，不同LKF制剂的MAF和IFN活性的完整或修饰形式显示出强烈的相关性，表明MAF活性的产生和变性与IFN抗病毒活性的产生和变性成比例。这项研究的结果提供了有力证据，表明MAF和IFN抗病毒活性实际上可能存在于相同的分子种类中。
