多种动物Mx基因的研究进展

Mx(myxovirus resistance)蛋白是由Ⅰ型干扰素(IFN)诱导表达的众多抗病毒蛋白中的一员,是一种具有GTP酶活性的肌动蛋白,在人、其他哺乳动物、家禽、鱼类等多种物种体内都广泛存在。Mx蛋白可抑制RNA病毒的复制,如水疱性口炎病毒(VSV)、狂犬病毒等,对某些DNA病毒也有效果,如乙型肝炎病毒。由于其具有广谱的抗病毒作用,所以也是目前国内外研究最广泛的几种抗病毒蛋白之一。文章对多种物种的Mx基因编码蛋白的结构、多态性、功能多样性及抗病毒作用等方面进行了综述,最后对Mx蛋白的应用和前景进行了探讨。     

不同动物Mx蛋白抗病毒研究进展

Mx(myxovirus resistance)蛋白是干扰素诱导产生的具有GTP酶活性的广谱抗病毒蛋白,可抑制病毒复制。本文综述了Mx蛋白结构及其功能,阐述了其抗病毒的作用机制,并对Mx蛋白在抗病毒免疫蛋白方面的应用前景进行了探讨。     

猪Mx1基因的克隆表达及抗病毒活性研究

本文应用(RT-PCR)技术,从猪瘟弱毒疫苗和Poly:IC共刺激7 h的PK15细胞的cDNA中扩增出编码Mx1蛋白的全长基因,并通过引物设计填补了PK(15)细胞系Mx1 cDNA序列中3’端11bp的缺失,成功获得Mx1完整基因的克隆。构建了重组表达质粒pRetroQ-sMx1,转染HEK293T细胞并表达Mx1蛋白,利用微量细胞病变抑制法测定其抗病毒活性。双酶切鉴定和核酸序列测定证实pRetroQ-sMx1真核表达质粒构建成功,转染HEK 293T细胞后,能够检测到绿色荧光,Western blot证实为目的蛋白。微量细胞病变抑制法测定重组蛋白具有一定的抗水疱性口炎病毒及猪繁殖与呼吸综合征病毒的活性。重组Mx1具有一定抗病毒生物功能,为进一步研究重组Mx1蛋白的活性以及Mx1抗病毒药物奠定了基础。     

禽类M_x基因的研究进展

Mx蛋白是干扰素诱导表达的抗病毒蛋白家族中的成员之一。与哺乳动物相比,禽类Mx基因的研究相对较少。现从禽类Mx基因的发现、编码蛋白的结构、多态性及功能多样性和抗病毒作用进行了综述,并对禽类Mx蛋白的应用和展望进行了探讨。     

鸡Mx蛋白抗病毒作用研究进展

Mx蛋白是在脊椎动物机体细胞受病毒感染或诱生剂处理时由Ⅰ型干扰素诱导表达的一种抗病毒蛋白。Mx 蛋白具有良好的抗病毒能力,靶向许多 RNA 病毒,诸如流感病毒、水疱性口炎病毒、狂犬病毒等,对某些 DNA 病毒,例如乙型肝炎病毒也有一定的作用。近年来,基于鸡的 Mx 蛋白抗病毒作用及机制的相关研究逐渐增多,取得了一些进展。论文就近年来鸡 Mx 蛋白的抗病毒机制与分子生物学特点进行综述,针对鸡 Mx 蛋白在抗病毒与品种鸡抗病育种筛选等应用前景进行分析与探讨。     

Mx抗病毒蛋白在水禽业抗病育种中的研究展望

Mx蛋白是I型干扰素（IFN）诱导下产生的具有抗病毒功能的蛋白质,属于大分子GTP酶动态蛋白（dynamin）超家族,大多数的脊椎动物有1～3个不同细胞内定位的Mx蛋白异构体,一般定位于核内或胞质中。Mx蛋白对RNA和DNA病毒具有广谱的抗病毒能力;其特征在N端有一个三联体GTP结构域和发动蛋白家族的结构特征序列,以及C端高度保守的亮氨酸拉链结构域,该区域是进行亚细胞定位及与病毒直接作用的区域。本文介绍了Mx蛋白发现、结构、抗病毒活性机制,并对水禽类MX蛋白在水禽抗病育种中的应用进行了展望。     

北京鸭Mx基因克隆及其在鸭呼肠孤病毒感染的鸭胚成纤维细胞中的表达分析

本试验旨在研究北京鸭Mx基因的结构及功能。利用干扰素诱导剂Poly(I:C)诱导鸭胚成纤维细胞(DEF),提取细胞总RNA,采用RT-PCR方法扩增北京鸭Mx基因全长编码区序列,并观察其在感染了鸭呼肠孤病毒(DRV)的DEF中的动态表达情况。北京鸭Mx基因序列分析结果显示,该基因编码区全长2166 bp,编码721个氨基酸残基。通过与GenBank中已登录的脊椎动物Mx基因进行核苷酸系统进化树分析,结果显示北京鸭Mx基因与野鸭Mx基因关系最近。北京鸭Mx序列与其他动物基因序列的比对结果显示,核苷酸同源性为47.8%~99.8%,氨基酸同源性为47.9%~99.4%。DRV孵育DEF后,Mx呈波动性表达。结果表明,本试验成功克隆了北京鸭Mx基因,预测分析证实其编码的蛋白具有脊椎动物Mx蛋白共有的结构特征,北京鸭Mx蛋白全基因的获得为下一步研究禽类Mx蛋白的抗病毒活性、作用机制及干扰素的监测奠定了基础。     

Mx蛋白研究进展

Mx蛋白是干扰素诱导表达的抗病毒蛋白家族中的成员之一。人、哺乳动物、鱼类、家禽体内都有Mx蛋白。Mx蛋白具有GTP酶活性 ,在其肽链氨基端均包含一个氨基酸序列高度保守的的三联GTP结合区域 ,羧基端存在有亮氨酸拉链区域。人和鼠的Mx蛋白有抗病毒活性。家禽中鸭的Mx蛋白无抗病毒活性 ;鸡的Mx蛋白的抗病毒活性受 6 31位氨基酸的影响 ,当 6 31位氨基酸为天冬酰胺时有抗病毒活性 ,为丝氨酸时则无抗病毒活性。文章最后对禽类Mx蛋白的应用和展望进行了探讨     

鸡Mx基因的克隆与原核表达

本研究旨在通过克隆鸡Mx全基因序列进而进行该基因的原核表达,获得具有生物学活性的蛋白.利用poly Ⅰ:C诱导鸡胚成纤维细胞Mx基因表达,克隆了Mx基因全长cDNA序列,将开放阅读框(ORF)连接构建于表达质粒pGEX-4t-2中获得重组表达载体pGEX-Mx,转化Rosetta(DE3)菌株,经IPTG诱导后检测.表达产物检测显示该蛋白的相对分子量为75 ku.说明获得了Mx基因的高效表达,为进一步进行Mx基因的活性检测以及利用Mx蛋白进行抗病毒转基因的研究奠定了基础.     

Mx抗病毒蛋白在水禽业抗病育种中的研究展望

随着我国水禽业的飞速发展，其集约化程度的提高、饲养条件的恶化或改变、抗生素的药物残留问题、病毒抗原漂移、超强毒株或新型传染病的出现及母源抗体的干扰等系列问题，在生产上引起大量的死亡或造成亚健康状态，进而造成巨大经济损失。这迫使我们要探索新的防疫途径和重新重视抗病育种的研究。Mx蛋白是干扰素（IFN）在体内主要诱导合成的一种特异的抗病毒蛋白，如小鼠Mx1蛋白证明能抑制流感病毒、多里病毒、索戈托病毒的复制；小鼠Mx2蛋白能抑制棒状疱疹性口炎病毒的复制；人MxA蛋白能抑制麻疹副粘病毒、棒状疱疹性口炎病毒、布尼亚病毒、白蛉病毒、汉坦病毒、3型腺病毒的复制”。本文介绍了国内外Mx蛋白的发现历程、结构、抗病毒活性并探讨了Mx蛋白在水禽抗病育种和抗病毒诊断治疗方面研究的必要性，旨在为培育整体免疫力高的水禽品系奠定理论基础。     

鸡Mx基因的原核表达及表达蛋白抗病毒活性初步研究

将鸡Mx基因克隆入pET一32a载体,筛选鉴定后将重组阳性质粒转化到大肠埃希菌株BL21进行诱导表达,表达产物用west,ern blot鉴定,并经镍亲和层析法纯化及透析复性,得到的蛋白用微量细胞病变抑制法检测其抗病毒活性.结果显示,构建的载体经PCR扩增得到长度为2 118 bp的特异片段,测序结果证实与鸡Mx基因同...     

Stimulation with a class A CpG oligonucleotide enhances resistance to infection with feline viruses from five different families

ABSTRACT: Domestic cats are commonly affected by viral pathogens that induce lengthy infections with fatal outcomes. Prevention of viral propagation is of primordial importance in shelters and catteries, where cats from different backgrounds have narrow contacts. Oligonucleotides (ODN) containing cytosine-phosphate-guanosine motifs of class A (CpG-A) are highly potent synthetic inducers of innate antiviral mechanisms. The aim of this study was to test their ability to modulate innate immune responses and prevent viral replication as stand-alone agents in the domestic cat. CpG-A stimulation of feline peripheral blood mononuclear cells (PBMCs) enhanced their proliferation, increased the presence of co-stimulatory molecules on their surface and influenced their gene expression profiles in an antiviral orientation. Incubation of the supernatants of CpG-A stimulated PBMCs with feline cell lines of epithelial and fibroblastic origin induced expression of the antiviral myxovirus resistance (Mx) gene in these target cells, which also showed enhanced resistance to feline viruses from five distinct families, namely Coronaviridae, Herpesviridae, Caliciviridae, Parvoviridae, and Retroviridae. Most importantly, subcutaneous administration of CpG-A in domestic cats systemically increased the expression of Mx, reaching maximal levels within 24 h. Plasma from treated cats could furthermore inhibit viral replication in vitro. Altogether, our data highlight the promising potential of CpG-A to induce a preventive antiviral state in the cat and to protect feline populations against a broad range of virus infections.     

绵羊ZAP基因克隆与生物信息学分析

锌指抗病毒蛋白(ZAP)是一种重要的宿主限制性因子,能够抑制多种病毒的增殖.为研究绵羊ZAP(oZAP)的生物信息学特征和对该蛋白功能进行预测,本研究通过PCR扩增oZAP基因,其长度为2697 bp,编码898个氨基酸;生物信息学分析显示oZAP蛋白中丝氨酸(Ser)含量最高,半衰期为30 h,属于不稳定的亲水性蛋白...     

Cloning of Mx Gene of Beijing Duck and its Expression Analysis in DEF Incubated with Duck Reovirus

The study was aimed to research the structure and function of Mx gene in Beijing duck.Full-length sequence of Beijing duck Mx gene was amplified by RT-PCR from the total RNA extracted from duck embryo fibroblast(DEF) induced by Poly(I:C).Furthermore, the expression of Mx gene in DEF infected with DRV was described.Sequence analysis indicated that the duck Mx gene contained an open reading frame(ORF) of 2166 bp encoding a protein of 721 amino acids.A phylogenetic tree based on Mx gene sequence was constructed.The results showed that Beijing duck Mx gene had the lowest distance with the gene from wild duck available in GenBank.Homology analysis showed that Beijing duck Mx gene nucleotides and deduced amino acids shared 47.8% to 99.8% and 47.9% to 99.4% homologies with those from other animals available in GenBank, respectively.Fluctuation expression of Beijing duck Mx gene was found with DEF incubated with duck reovirus.Duck Mx gene was successfully cloned and predicted with characteristic of typical structure of Mx family.Gaining Beijing duck Mx gene laid a foundation for further researching Mx protein antiviral activity, molecular mechanism and interferon monitoring of poultry.     

Interferon mediated antiviral activity against salmonid fish viruses in BF-2 and other cell lines

Double-stranded RNA and type I interferon-like activity induce an antiviral state in vertebrate cells and in several fish cell lines by increasing the expression of proteins that inhibit virus replication. We compared the protection induced by the polyinosinic:polycytidylic acid (poly I:C) or poly I:C plus transfection agents against the infectious pancreatic necrosis virus (IPNV) and the infectious hematopoietic necrosis virus (IHNV) in BF-2 cells, with that induced in RTG-2, CHSE-214, or SAF cells. In addition, we examined the reduction in the infective titers of these viruses and the correlation with Mx protein expression as IFN marker. Furthermore, the suitability of BF-2 cells for the evaluation and optimization of immune responses in an IPNV-IHNV co-infection was assessed. The results demonstrated strong anti-IPNV and anti-IHNV activity (around 90% of infected cells surviving) in BF-2 cells transfected with poly I:C, in which a loss of 1log(10) or 3log(10) of the IPNV or IHNV infective titers, respectively, was observed. No antiviral activity was evident in the cells incubated with poly I:C alone. The protection recorded in the co-infection experiments was comparable with those of the single infections. The SAF cell line exhibited the lowest antiviral capacity (45%), which was also increased after transfection with poly I:C. In addition, medium from transfected BF-2 provided protection against IPNV (1log(10) loss of infective titer) and IHNV (2log(10) loss of infective titer) in new monolayers, indicating that these cells secreted the factors that induce antiviral activity. A correlation between antiviral activity and Mx protein expression was observed in all the cells. These results indicate that poly I:C transfection could improve IFN-like production in these cell lines. However, the antiviral effectiveness of poly I:C differed between cell lines. On the basis of our findings, we conclude that the BF-2 cell line is a useful model in which to study the role of IFN-induced cytokines in resistance against single or double infections with salmonid fish viruses.     

Polymorphisms and the antiviral property of porcine Mx1 protein

We determined the cDNA sequences of the type I interferon-inducible proteins, pig Mx1 from PK(15) and LLC-PK1 cells, and compared the antiviral activities of both Mx proteins, including Mx1 polymorphisms against vesicular stomatitis virus (VSV). Mx1 cDNA derived from PK(15) cells had an 11 bp-deletion in the 3' end of the coding region, and was estimated to encode 8 amino acid substitutions and a 23 amino acid extension compared to that from LLC-PK1 cells. VSV replication was inhibited in the 3T3 cells expressing Mx1 mRNA after the cDNA was transfected. However, the efficiency of this inhibition was not different between the cells expressing Mx1 mRNA from both PK and LLC. These results indicate that pig Mx1 protein confers resistance to VSV.