HCV全长cDNA细胞培养适应性突变体的构建及其体外转录制备感染性RNA的研究

运用重叠延伸PCR方法对HCV全长基因组cDNANS3和NS5A上的E1202G、T1280I和S2197P进行细胞培养适应性突变,构建含有细胞培养适应性突变的HCV全长基因组cDNA,体外转录制备RNA,脂质体法转染人肝癌细胞Huh-7,以RT-PCR检测HCV正、负链RNA,间接免疫荧光法和Western blot检测细胞内HCVNS3蛋白的表达。结果证明,转染后细胞内可间断检测到HCV正、负链RNA及HCVNS3蛋白的表达,且突变体RNA与未突变的HCVRNA相比,明显具有更高的复制效率和蛋白表达。该研究为后续HCV体外培养体系的研究提供了可在细胞内高效自主复制的HCV病毒模板。     

病毒基因组中的对称性

病毒基因组中的重复序列比率很低,因为其核酸序列大都是编码区域.如果出现一段同向对称或者是反向对称序列在病毒基因组中,它往往代表一个调控元件,或者是一个信号因子.我们总结了病毒中的一些对称序列,并阐明它的特点,分布及功能.     

移动U盘病毒工作原理、清除与防范

对移动U盘病毒工作原理进行了分析，在此基础上以流行的U盘病毒RavMon．exe为例，提出了对这类病毒感染的清除方法，以及基于类DOS下创建免疫文件夹的主动防范策略。     

Protective effect of Shigyaku-to,a traditional Chinese herbal medicine,on the infection of herpes simplex virus type 1 (HSV-1) in mice

The antiviral activity of Shigyaku-to (TJS-109), a traditional Chinese herbal medicine, was investigated in mice infected with herpes simplex virus type 1 (HSV-1). TJS-109 is a combination of the medicinal plant extracts fromZingiberis siccatum rhizoma,Aconiti tuber andGlycyrrhizae radix in a specific proportion. Mice infected with a 10 LD₅₀ dose of HSV-1 were treated with TJS-109 orally at doses of 1.25 to 20 mg/kg 2 days before, and 1 and 4 days after the infection. The treated groups had 80% (1.25 mg/kg), 40% (5 mg/kg) and 23% (20 mg/kg) mortality rates 25 days after the infection as compared with a 100% mortality rate in control mice treated with saline. When HSV-1 infected mice (recipients) received CD8⁺T cell fractions derived from spleens of mice treated with TJS-109 (donors), 70% of recipients survived, as compared with 0% survivors in the groups of mice treated with saline, B cell fractions, CD4⁺ T cell fractions or macrophage-enriched fractions prepared from the same donors. TJS-109 did not show any virucidal activities against HSV-1 or any virostatic activities on the growth of HSV-1 in Vero cells. These results suggest that TJS-109 protected mice exposed to lethal amounts of HSV-1 through the activation of CD8⁺ T cells.     

茶刺蛾[Darna trima(more)]颗粒体病毒鉴定及核酸与蛋白质特性的初步研究

1985年从四川珙县分离到的茶刺蛾病原物,经感染试验,组织病理研究,包涵体及病毒粒子超微结构研究,核酸类型鉴别等,定名该病原物为茶刺蛾颗粒体病毒.另对该病毒核酸作了限制性内切酶分析和热变性试验,测得该病毒核酸为双链DNA分子,分子量为64.11×10~6d,93.87kb,Tm值为67.3℃,(G+C)含量为32.7％,包涵体蛋白的氨基酸组分中Asp、Glu和Arg含量高,占氨基酸总量的34.12％,His,Cys和Met含量很少。该病毒对茶刺蛾幼虫有很强的感染力,氨基酸在生物防治上有潜在应用前景.     

Peptide aptamers: exchange of the thioredoxin-A scaffold by alternative platform proteins and its influence on target protein binding

Peptide aptamers have emerged as powerful new tools for molecular medicine. They can specifically bind to and functionally inactivate a given target molecule under intracellular conditions. Typically, peptide aptamers are generated by screening a randomized peptide expression library, displayed from the Escherichia coli thioredoxin A (TrxA) protein. Here, we transferred peptide moieties from defined TrxA-based peptide aptamers to alternative scaffold proteins, such as the green fluorescent protein and staphylococcal nuclease. Yeast and mammalian two-hybrid assays as well as in vitro binding analyses show that the TrxA scaffold can be a major determinant for the binding of peptide aptamers. In addition, we demonstrate that TrxA can correctly display peptide sequences that correspond to the binding domains of natural interaction partners. Therefore, sequence analyses of TrxA-based peptide aptamers, isolated by two-hybrid screening from randomized expression libraries, should also be useful to find cellular binding partners for a given target protein, by homology. Received 1 August 2002; received after revision 17 September 2002; accepted 19 September 2002 RID="*" ID="*"Corresponding author.     

禽白血病研究进展

禽白血病(AL)是由病毒引起的一种肿瘤性传染病,感染率高,发病率低,是危害养鸡业的主要疾病之一[1].本文主要介绍了其病原学、流行病学、诊断、预防等几个方面的研究近况,旨在加强对禽白血病的防制.     

抵御蠕虫攻击的一种方法-Honeypot系统

Internet大面积遭受蠕虫攻击的事件时有发生，针对这种问题，引入Honeypot技术，结合入侵检测系统(IDS)、数据挖掘提出了一种解决办法：将Honeypot置于DMZ中，利用其欺骗地址空间技术覆盖服务器中没有用到的IP地址，捕获蠕虫；IDS监控流入网络的数据包，对入侵作出反映；系统日志异地保存。该系统能有效抵御目前已经出现的蠕虫攻击，同时对新出现的目前未知的蠕虫攻击也有很好的防御效果。     

Progress in non-viral gene delivery systems fabricated via supramolecular assembly

Gene delivery systems are one of key issues that limit the development of gene therapy. The novel non-viral gene delivery systems fabricated via supramolecular assembly have begun to show increasing promising and applications in gene therapy due to its suitable nanometric size,controllable structure and excellent biocompatibility. In this review, the fundamental and recent progress of non-viral gene supramolecular assembly is reviewed. Artificial viruses the future direction of non-viral gene delivery systems are also described.     

Two virus-encoded RNA silencing suppressors, P14 of Beet necrotic yellow vein virus and S6 of Rice black streak dwarf virus

Functional analysis for gene silencing suppressor of P14 gene of Beet necrotic yellow vein virus and S6 gene of Rice black streak dwarf virus was carried out by agro- infiltration with recombinant vectors of Potato virus X. The phenotype observation of green fluorescent protein (GFP)expression and Northern blot showed that the gene silencing of gfp transgenic Nicotiana benthamiana induced by homologous sequence was strongly suppressed by the immixture infiltration of either the P14 or the $6. In the suppressed plants, the gfp mRNA accumulation was higher than that in the non-suppressed controls and the symptoms caused by PVX infection became more severe, especially the gfp DNA methylation of plant genome was significantly inhabited when co-infiltrated with RBSDV S6 gene. These results suggested that these two virus genes were potentially to encode for proteins as RNA silencing suppressors.