Pteropine Orthoreovirus(PRV7S)does not Establish Persistent Infection in NP460 Cells but with Inflammatory Response Triggered

Pteropine orthoreovirus(PRV)is a nonenveloped double-stranded RNA(dsRNA)virus of the genus Orthoreovirus under the family Reoviridae.The PRV genome is composed of 10 dsRNA segments,including three large(L)segments,three medium(M)segments,and four small(S)segments surrounded by an icosahedral capsid[1].

禽类呼肠孤病毒(Avian reoviruses)感染

1病原学 1.1病毒特征禽类呼肠孤病毒为无囊膜,呈球形,双层衣壳和二十面对称的dsRNA病毒.粒子直径约60～80 nm,外层衣壳上有92颗中空的颗粒.在CsCl梯度离心中,感染病毒子的密度为1.29～1.30g/ml,无感染性空衣壳为1.29～1.30g/ml,病毒芯髓为1.44 g/ml.纯化病毒只含有RNA和蛋白质,平均含量分别为18.7%和81.3%.病毒在胞浆内复制,有时呈晶格排列.对热、pH 3和DNA代谢抑制物有抵抗力.MgCl2能增强病毒对热的稳定性,但当浓度太大时反而促其灭活.70%乙醇和0.5%有机碘可灭活病毒.一般无血凝活性. ……

Establishment of Universal RT-PCR Detection Method for Duck Reovirus

This study was conducted to rapidly detect clinical infection condition of duck reovirus. A pair of specific primers was designed according to gene se- quence of σC protein of duck reovirus, and a specific RT-PCR detection method of duck reovirus was established with genome of duck reovirus as template. Differ- ent samples were collected from ducks infected by suspected reovirus in Jiangsu Province and subjected to PCR detection. The results showed that the established RT-PCR method could specifically amplify the 438 bp sequence of the conservative region of σC gene, and detec the DNA of duck rcovirus as low as 1gf, with a detection rate of 100%. The RT-PCR method could be used for rapid clinical diagnosis of duck reovirus.

Development of Oncolytic Reovirus for Cancer Therapy

Reovirus, a double-stranded RNA virus, can infect many types of cancer cells and cause oncolysis. Mammalian reovirus has exhibited promising anticancer activity in clinical trials and holds great advantages and promise as an anticancer agent. Reovirus is not associated with any serious human diseases, naturally targets and destroys tumors, and lacks the DNA synthesis stage, thus avoiding potential DNA insertion mutations. This review discusses the properties of reovirus related to oncolysis and the mechanisms of oncolytic selection, and summarizes the preclinical and clinical studies that have led to the current Phase III trial. In addition, three major challenges in the development of reovirus-mediated oncolytic therapy are discussed. These are: the mechanisms of reovirus oncolysis remain to be fully characterized;the host immune responses should be manipulated to enhance viral anti-tumor effects;and the efficacy of reovirus oncolysis may be further improved by developing new vectors and studying other double-stranded RNA viruses.

Construction of Short Hairpin RNA Vector with σNS & σC Genes of Avian Reovirus and Determination of Interference Effect

[ Objective] The aim was to explore novel method for treatment of Avian Reovirus. [ Method] According to the design principle of siRNA target sequences, siRNA templates were designed and synthesized and then cloned into the shRNA expression vector, namely, pSilencer-CMV 4.1 neo. Short hairpin RNA vector C1, C2, C3, which contain σC gene, and shRNA vector NS1, NS2, NS3, which contain aNS gene, were constructed separately. The constructed shRNA vectors and negative control were co-transfected into DF-1 cells with the eukaryotic expression vector pEG- FP-σC and pEGFP-σNS, respectively. [ Result] Observation through fluorescence microscope indicated that the constructed 6 shRNA could inhibit the expression of fusion protein to different degrees. In addition, results of Real-time PCR suggested that C3 and NS1 have the best interference effect to the viral duplication in vitro. [ Conclusionl Construction and selection of specific shRNA expression vectors inhibiting Avian Reovirus are significant for researching effects of σC and oNS proteins in infection and duplication of ARV, providing new idea for ARV antiviral therapy.

Sequence and phylogenetic analysis of chicken reoviruses in China

supported by the China Animal Disease Prevention and Control Center;the China Agriculture Research System Poultry-Related Science and Technology Innovation Team of Peking, China （CARS-PSTP）

High-resolution 3D Structures Reveal the Biological Functions of Reoviruses

Viruses in the family Reoviridae are non-enveloped particles comprising a segmented double-stranded RNA genome surrounded by a two-layered or multi-layered icosahedral protein capsid.These viruses are classified into two sub-families based on their particle structural organization.Recent studies have focused on high-resolution three-dimensional structures of reovirus particles by using cryo-electron microscopy (cryo-EM) to approach the resolutions seen in X-ray crystallographic structures.The results of cryo-EM image reconstructions allow tracing of most of the protein side chains,and thus permit integration of structural and functional information into a coherent mechanism for reovirus assembly and entry.

Temperature-regulated typeⅡgrass carp reovirus establishes latent infection in Ctenopharyngodon idella brain

Grass carp reovirus(GCRV)causes extensive infection and death in grass carp and black carp fingerlings,with a highly seasonal prevalence.Previous studies suggested that GCRV can become latent after primary infection.In this study,we investigated type II GCRV(GCRV-II)latency in asymptomatic grass carp with GCRV infection or exposure history.We found that during latent infection,GCRV-II was detectable only in the brain of grass carp,unlike the multi-tissue distribution observed in natural infection.GCRV-II only caused damage to the brain during latent infection,while in natural infection,brain,heart,and eye tissues had relatively higher viral loads.We also discovered viral inclusion bodies in infected fish brains.Additionally,GCRV-II distribution in grass carp was notably affected by ambient temperature,with the virus targeting the brain only during low temperatures and multi-tissue distribution during high temperatures.This study provides insights into the mechanisms of GCRV-II latent infection and reactivation and contributes to the prevention and control of GCRV pandemics.

Asymmetric reconstruction of the aquareovirus core at near-atomic resolution and mechanism of transcription initiation

Dear Editor,Aquareovirus(ARV,Reoviridae)causes hemorrhagic disease in the economically important golden shiner and grass carp of America and China,respectively(Nason et al.,2000;Fang et al.,2005).Reoviridae members are characterized by endogenous transcription of their multipartite genomes within capsids of 1-3 layers and are further classified based on the presence(Spinareovirinae subfamily,9 genera)or absence(Sedoreovirinae subfamily,6 genera)of mRNA-capping turrets along the innermost layer(King et al.,2012).

3D reconstruction and capsid protein characterization of grass carp reovirus

Grass carp reovirus (GCRV) is a relatively new virus first isolated in China and is a member of the Aquareovirus genus of the Reoviridae family. Recent report of genomic se-quencing showed that GCRV shared high degree of homology with mammalian reovirus (MRV). As a step of our effort to understand the structural basis of GCRV pathogenesis, we determined the three-dimensional (3D) structure of GCRV capsid at 17 ? resolution by electron cryomicro-scopy. Each GCRV capsid has a multilayered organization, consisting of an RNA core, an inner, middle and outer protein layer. The outer layer is made up of 200 trimers that are arranged on an incomplete T=13 icosahedral lattice. A characteristic feature of this layer is the depression re-sulting from the absence of trimers around the peripentonal positions, revealing the underlying trimers on the middle layer. There are 120 subunits in the inner layer arranged with T=1 symme-try. These structural features are common to other members of the Reoviridae. Moreover, SDS-PAGE analysis showed that GCRV virions contain seven structural proteins (VP1-VP7). These structural proteins have a high degree of sequence homology to MRV, consistent with the structural similarities observed in our study. The high structural similarities of isolated GCRV and MRV suggest that future structural studies focusing on GCRV entering into and replicating within its host cell are necessary in order to fully understand the structural basis of GCRV pathogenesis.

Characterization of viral entry and infection of quantum dot-labeled grass carp reovirus

Dear Editor,Reoviruses are non-enveloped icosahedral virions with an outer capsid surrounding their cores,which harbor the10–12 segmented double-stranded RNA(ds RNA)genome.To date,there are 15 proposed genera in the family Reoviridae(King et al.,2012),including Aquareovirus.Generally,aquareoviruses are of low pathogenicity in aquaculture.However,grass carp reovirus(GCRV)is

呼肠孤病毒在肿瘤治疗研究进展

在过去的几十年间,溶瘤病毒（oncolytic virus,OV）在肿瘤治疗中已取得了很多突破性进展。野生型或经改造的OV可通过在肿瘤细胞内大量复制增殖来溶破肿瘤细胞,而对正常细胞无破坏作用。野生型呼肠孤病毒（reovirus）可选择性在肿瘤细胞内增殖,已证实其对多种来源的肿瘤细胞均可发挥溶瘤效应。

番鸭呼肠孤病毒L2基因的序列分析

番鸭呼肠孤病毒感染是危害番鸭养殖业的一种重要传染病,其病原是番鸭呼肠孤病毒（Muscovy duck reovirus,MDRV）[1]。MDRV感染于1950年在南非首次报道[2],随后在法国[1]、以色列[3]等国亦有发生,1997年后,该病出现于我国,并广泛流行于福建、广东、浙江、广西、江苏等地[4-11]。该病分为两种＂病型＂。

草鱼(Ctenopharyngodon idella)组织蛋白酶L基因克隆及表达特性分析

为探究组织蛋白酶L(Cathepsin L,CtsL)是否在草鱼(Ctenopharyngodon idella)体内发挥免疫功能,根据已构建的草鱼肌肉转录组数据库中unigene序列,采用RACE技术首次克隆得到全长为1 496 bp的草鱼组织蛋白酶L基因(CiCtsL)cDNA序列。序列分析和同源建模显示该基因编码的蛋白具备组织蛋白酶前体抑制结构域I29和木瓜蛋白酶家族半胱氨酸蛋白酶Pept_C1结构域。系统进化分析表明,CiCtsL与斑马鱼CtsL聚为一支。CiCtsL mRNA在7个组织中均有表达,其中肝脏中的相对表达水平最高。感染GCRV后,CiCtsL在各组织中的表达量显著上调,呈现先上升后下降的趋势。研究表明CiCtsL参与了草鱼抵抗GCRV的免疫应答反应,可在草鱼先天免疫调控中发挥重要作用。

新型鸭呼肠孤病毒病研究进展

本文针对近年来新型鸭呼肠孤病毒病的研究报道,对该病的病原学、流行病学、病原学诊断、血清学诊断、防治措施及致病机制等方面进行总结,较全面地阐述该病的研究进展,为该病的深入研究和预防治疗提供参考。

果子狸源呼肠孤病毒的分离鉴定

在广东省采集的果子狸样品共192份,处理后接种Vero-E6细胞,从中分离到1株病毒。该病毒在Vero-E6细胞上盲传至第4代开始出现细胞病变,表现为细胞内颗粒增多,细胞收缩、变圆,最后细胞从瓶壁脱落。经电镜观察发现,病毒粒子无囊膜,有双层衣壳,呈正二十面体对称,具有呼肠孤病毒的形态特征,将病毒命名为MaskedPal m Civet/China/2004(MPC/04)。红细胞凝集试验表明该病毒能凝集健康人O型血红细胞,不能凝集SPF鸡、实验用普通级牛、大鼠和豚鼠的红细胞,这与哺乳动物呼肠孤病毒血清1型的红细胞凝集谱相符。理化特性试验表明该病毒对氯仿有抵抗力;能耐受pH3.0的酸性环境;50℃水浴1h病毒未丧失感染能力;1mol/L MgCl2能提高病毒对热的抵抗力。为了进一步从分子水平上证实该病毒是呼肠孤病毒,用哺乳动物呼肠孤病毒特异性引物进行反转录-聚合酶链式反应(Reverse transcription polymerase chain reaction,RT-PCR),扩增得到了预期大小的片段。测序结果经NCBI BLAST比较,选取同源性较高者进行序列同源性分析,发现该片段与哺乳动物呼肠孤病毒血清1型参考毒株核苷酸同源性最高。以上结果证明该病毒为呼肠孤病毒科的成员。

禽源呼肠孤病毒S1基因节段分子生物学研究进展

呼肠孤病毒广泛的宿主性以及自身基因组的结构特征使其在进化过程中呈现遗传多样性,新型禽源呼肠孤病毒在此过程中不断出现,引起家禽和水禽养殖业的严重经济损失。其中,关于S1基因节段的科学研究对于理解病毒致病性改变以及疫苗开发有关键作用。因此,本文拟就禽源呼肠孤病毒的发生、S1基因的结构及其编码的非结构蛋白P10、P17和结构蛋白σC的生物学功能最新研究进展作一概述。

肉鸡发育障碍与矮小综合征

肉鸡发育障碍与矮小综合征是一种包括肠道损害等多症状的传染性疾病,目前已遍布世界各地,在蛋鸡、珍珠鸡和火鸡中均有发生,是一个严重威胁现代养禽业的重大问题。论文从肉鸡发育障碍与矮小综合征的临床症状、病理变化和病原学对其进行了综述,以期为本病的诊断和预防提供参考。

植物呼肠孤病毒研究的最新进展

植物呼肠孤病毒是一类形态复杂、具有多种病毒结构蛋白及片段化双链RNA基因组的病毒,一直受到病毒学家的注意。