Eosinophil cationic protein RNase 3 is another RNaseA-family ribonuclease with direct antiviral activity
Eosinophil cationic protein RNase 3 is another RNaseA-family ribonuclease with direct antiviral activity
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DOI：
10.1093/nar/26.14.3358
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发表时间：
1998-07-15
影响因子：
14.9
通讯作者：
Rosenberg, HF
中科院分区：
文献类型：
--
作者：
Domachowske, JB;Dyer, KD;Rosenberg, HF
嗜酸性粒细胞阳离子蛋白（ECP）是在人嗜酸性白细胞的分泌颗粒中发现的两种RNase A超家族核糖核酸酶之一，尽管嗜酸性粒细胞[以及两种嗜酸性粒细胞核糖核酸酶ECP和嗜酸性粒细胞衍生的神经毒素（EDN）]的生理功能仍然存在争议，但我们最近已经表明，分离的人嗜酸性粒细胞促进核糖核酸酶依赖的对单链RNA病毒的细胞外病毒粒子的毒性，呼吸道合胞病毒B组（RSV-B）。我们还表明重组人EDN（rhEDN）可以单独作为核糖核酸酶依赖性抗病毒剂。在这项工作中，我们提供了一个生化特性的重组人ECP（rhECP）在杆状病毒中制备，并证明，rhECP也促进核糖核酸酶依赖的抗病毒活性。这里描述的rhECP是N-糖基化的，天然ECP也是如此，并且具有比在细菌中制备的非糖基化rhECP高100倍的核糖核酸酶活性。胎盘核糖核酸酶抑制因子（RI）对rhECP的酶活性有明显的抑制作用。尽管rhECP在降低病毒感染性方面不如rhEDN有效（500 nM rhECP使RSV-B的感染性降低约6倍; 500 nM rhEDN>50倍），但抗病毒活性似乎是嗜酸性粒细胞核糖核酸酶所独有的;牛核糖核酸酶A、两栖动物核糖核酸酶、癌蛋白酶和密切相关的人核糖核酸酶、核糖核酸酶k6均未促进感染性降低。有趣的是，rhEDN和rhECP的组合没有产生协同或甚至相加的抗病毒作用。综上所述，这些结果表明，嗜酸性粒细胞核糖核酸酶和RSV-B的细胞外病毒粒子之间的相互作用可能是特异性的和饱和的。
Eosinophil cationic protein (ECP) is one of two RNase A-superfamily ribonucleases found in secretory granules of human eosinophilic leukocytes, Although the physiologic function of eosinophils [and thus of the two eosinophil ribonucleases, ECP and eosinophil-derived neurotoxin (EDN)] remains controversial, we have recently shown that isolated human eosinophils promote ribonuclease-dependent toxicity toward extracellular virions of the single-stranded RNA virus, respiratory syncytial virus, group B (RSV-B), We have also shown that recombinant human EDN (rhEDN) can act alone as a ribonuclease-dependent antiviral agent. In this work, we provide a biochemical characterization of recombinant human ECP (rhECP) prepared in baculovirus, and demonstrate that rhECP also promotes ribonuclease-dependent antiviral activity. The rhECP described here is N-glycosylated, as is native ECP, and has similar to 100-fold more ribonuclease activity than nonglycosylated rhECP prepared in bacteria. The enzymatic activity of rhECP was sensitive to inhibition by placental ribonuclease inhibitor (RI). Although rhECP was not as effective as rhEDN at reducing viral infectivity (500 nM rhECP reduced infectivity of RSV-B similar to 6 fold; 500 nM rhEDN, >50 fold), the antiviral activity appears to be unique to the eosinophil ribonucleases; no reduction in infectivity was promoted by bovine RNase A, by the amphibian ribonuclease, onconase, nor by the closely-related human ribonuclease, RNase k6. Interestingly, combinations of rhEDN and rhECP did not result in either a synergistic or even an additive antiviral effect. Taken together, these results suggest that that the interaction between the eosinophil ribonucleases and the extracellular virions of RSV-B may be specific and saturable.