Effect of amino acid mutation at position 127 in 3A of a rabbitattenuated foot-and-mouth disease virus serotype Asia1 on viral replication and infection

An amino acid mutation(R127→I) in the 3A non-structural protein of an FMDV serotype Asia1 rabbit-attenuated ZB strain was previously found after attenuation of the virus. To explore the effects of this mutation on viral replication and infection, the amino acid residue isoleucine(I) was changed to arginine(R) in the infectious cDNA clone of the rabbit-attenuated ZB strain by sitedirected mutagenesis, and the R127-mutated virus was rescued. BHK monolayer cells and suckling mice were inoculated with the R127-mutated virus to test its growth property and pathogenicity, respectively. The effects of the R127 mutation on viral replication and virulence were analyzed. The data showed that there was a slight difference in plaque morphology between the R127-mutated and wild-type viruses. The growth rate of the mutated virus was lower in BHK-21 cells and its virulence in suckling mice was also attenuated. This study indicates that the R127 mutation in 3A may play an important role in FMDV replication in vitro and in pathogenicity in suckling mice.

Comparison of Three ELISA Kits for the Differentiation of Foot-and-mouth Disease Virus-infected from Vaccinated Animals

研究被执行验证工具包为 FMDV 的区别在中国开发了的 3 FMDV 3ABC-I-ELISA 感染并且种牛痘的动物。从天真、种牛痘的牛以及从被感染了的牛的 sera 的集合被商业诊断工具包对 FMDV 的 nonstructural 蛋白质(NSP ) 为抗体测试， Ceditest 吗？FMDV-NS (Ceditest？工具包) ， UBI？FMDV NONSTRUCTURAL 蛋白质 ELISA 方向插入(UBI？工具包) 并且一个 FMDV 3ABC-I-ELISA 工具包在 Lanzhou 发展了兽医研究院。三个工具包的测试参数(敏感和特性) 被决定，并且从 FMD 3ABC-I-ELISA 工具包获得的结果与从二个外国工具包获得了那相比。结果显示巧合在 FMDV 3ABC-I-ELISA 和 Ceditest 之间评价吗？工具包 98.05% 是，并且在 FMDV 3ABC-I-ELISA 和 UBI 之间的巧合率？工具包是 94.4% ；两 Ceditest 的敏感？并且 FMDV 3ABC-I-ELISA 工具包是 100% 。然而， UBI 的敏感？工具包仅仅是 81.8% 。与从天真或种牛痘的非感染的动物的 sera，所有测试的特性超过了 90% 。关键词 Foot-and-mouth 疾病病毒(FMDV )- 非结构的蛋白质 3ABC - ELISA CLC 数字 S852.65 基础项目：国家鈥 ? 73 鈥 ? 研究工程(G199901190， 2005CB23201 ) ；国际原子能机构(国际原子能机构)(10697/R2 )

The Complete Genomic Sequence of a Foot-and-Mouth Disease Virus Isolated from the Swine

The complete genomic sequence of foot-and-mouth disease virus (FMDV) Chinese strain OH/CHA/99 was determined. The 8040 nt sequence and the deduced amino acid sequence werecompared with FMDV sequences published. The results showed that OH/CHA/99 shared highersequence homology with OTYTW/97, indicating their close genetic relationship. However,the strain had lower sequence identity with O1/Kaufbeuren/66 strain. Besides, largedeletions in 3A coding region were observed in OH/CHA/99. It was shown that the poly (A)tail of OH/CHA/99 had 56 As at least.

Development of a Synthetic Peptide ELISA Assay for the Detection of Foot-and-Mouth Disease Virus Nonstructural Protein Antibodies

In order to develop an ELISA assay with synthetic peptides for the detection of antibody to the nonstructural proteins of foot-and-mouth disease virus, specific peptides were synthesized by a solid-phase method according to FMDV NSPs B-cell epitopes, and were conjugated to carrier protein BSA. An ELISA system was developed to detect FMDV NSPs antibody with the conjugated proteins as the coating antigen. The optimal coating concentration of the antigen was determined as 2.5 μg mL-1. The comparative study of this assay with UBI NSP ELISA kit and national commercial 3ABC ELISA kit in the detection of 199 serum samples showed that they were very coincident, and the identity rates were 96.48 and 97.48%, respectively. The development of ELISA using the synthetic peptides as coating antigen is specific, reproducible, stable, and easy, and can be used to differentiate FMDV infected pigs from immunized pigs.

Review of Air Dispersion Modelling Approaches to Assess the Risk of Wind-Borne Spread of Foot-and-Mouth Disease Virus

Foot-and-mouth disease virus (FMDV) is one of the most economically serious veterinary pathogens due to its negative effects on livestock and its highly infectious nature via a variety of transmission paths through oral and inhalation routes. Measures to enhance outbreak management can be designed according to analytical results predicted by mathematical models for wind-borne dispersion, an important path of virus transmission. Accurate atmospheric dispersion models are useful tools for properly determining risk management plans, while inaccurate models may conversely lead to accidental loss in two possible ways. Overly strict measures, e.g., slaughter for too wide an area, can cause severe economic difficulties, including irreversible loss of business operations for a number of farms. On the contrary, inestimable loss potentially caused by lax controls is a persistent threat. In this paper, available modelling procedures for forecasting the spread of FMDV, which have been used since the 1970s, each having its advantages and limitations, are reviewed for the purpose of ensuring suitable application in various conditions of any future emergency cases.

B Cell Epitopes within VP1 of Type O Foot-and-mouth Disease Virus for Detection of Viral Antibodies

In this study,the coding region of type O FMDV capsid protein VP1 and a series of codon optimized DNA sequences coding for VP1 amino acid residues 141-160(epitope1),tandem repeat 200-213(epitope2(+2)) and the combination of two epitopes(epitope1-2)was genetically cloned into the prokaryotic expression vector pPROExHTb and pGEX4T-1,respectively.VP1 and the fused epitopes GST-E1,GST-E2(+2)and GST-E1-2 were successfully solubly expressed in the cytoplasm of Escherichia coli and Western blot analysis demonstrated they retained antigenicity.Indirect VP1-ELISA and epitope ELISAs were subsequently developed to screen a panel of 80 field pig sera using LPB-ELISA as a standard test.For VP1-ELISA and all the epitope ELISAs,there were clear distinctions between the FMDV-positive and the FMDV-negative samples.Cross-reactions with pig sera positive to the viruses of swine vesicular disease virus that produce clinically indistinguishable syndromes in pigs or guinea pig antisera to FMDV strains of type A,C and Asia1 did not occur.The relative sensitivity and specificity for the GST-E1 ELISA,GST-E2(+2),GST-E1-2 ELISA and VP1-ELISA in comparison with LPB-ELISA were 93.3%and 85.0%,95.0%and 90%,100%and 81.8%,96.6%and 80.9%respectively.This study shows the potential use of the aforementioned epitopes as alternatives to the complex antigens used in current detection for antibody to FMDV structural proteins.

Amplification and Characterization of Bull Semen Infected Naturally with Foot-and-mouth Disease Virus Type Asia1 by RT-PCR

To investigate the security of semen biologically, 15 bull semen samples were collected (of which 5 exhibited clinical signs of Foot-and-mouth disease) and identified by RT-PCR and virus isolation. The results indicated that the semen of the infected bulls were contaminated by Foot-and-mouth disease virus (FMDV), but FMDV was not detected in semen samples from those bulls not showing clinical signs of Foot-and-mouth disease (FMD). This is the first report of the presence of FMDV in bull semen due to natural infection in China. The analysis of the partial sequence of the VP1 gene showed that the virus strain isolated from semen has 97.9% identity with the virus isolated from vesicular liquid of infected bulls showing typical signs of FMD and belonged to the same gene sub-group.

Expression,Purification and Activity Detection of Structural Protein VP1 of Foot-and-Mouth Disease Virus Serotype A

The paper was to obtain the VP1 protein of FMDV serotype A with high activity. With recombinant plasmid pMD19A-T-vp1 as the tem- plate, vpl gene fragment amplified by PCR was connected into prokaryotic expression vector pET28a to construct recombinant plasmid pET-A-vpl. The E. coli BL21 （DE3） strain containing recombinant plasmid pET-A-vpl were induced by IPTG. SDS-PAGE showed that VP1 protein was ex- pressed in the form of inclusion body, and its molecular weight was about 29 ku. Based on the optimizing IPTG concentration and expression time, the largest expression of VP1 protein was induced by 0.3 mmol/L IPTG for 6 h at 37 ℃. Western-Blot analysis indicated that the expression of VP1 protein could be specifically recognized by positive serum of FMDV serotype A. ELISA test showed that VP1 inclusion body protein had high activity after purification by washing and renaturation by urea concentration gradient dialysis.

Generation of Monoclonal Antibodies against Non-structural Protein 3AB of Foot-and-Mouth Disease Virus

To identify linear epitopes on the non-structural protein 3AB of foot-and-mouth disease virus (FMDV), BABL/c mice were immunized with the 3AB protein and splenocytes of BALB/c mice were fused with myeloma Sp2/0 cells. Two hybridoma monoclonal antibodies (mAbs) cell lines against the 3AB protein of foot-and-mouth disease virus (FMDV) were obtained, named C6 and E7 respectively . The microneutralization titer was 1:1024 for mAb C6, and 1:512 for E7. Both mAbs contain kappa light chains, and were of subclass IgG2b. In order to define the mAbs binding epitopes, the reactivity of these mAbs against FMDV were examined by indirect ELISA. The results showed that both mAbs can react with FMDV, but had no cross-reactivity with Swine Vesicular Disease (SVD) antigens. The titers in abdomen liquor were 1:5×106 for C6 and 1:2×106 for E7. In conclusion, the mAbs obtained from this study are specific for the detection of FMDV, can be used for etiological and immunological researches on FMDV, and have potential use in diagnosis and future vaccine designs.

Develope Monoclonal Antibody against Foot-and-mouth Disease Virus A Type

In order to develop an anti-FMDV A Type monoclonal antibody (mAb),BABL/c mice were immunized with FMDV A type.Monoclonal antibodies (mAbs) 7B11 and 8H4 against Foot-and-mouth disease virus (FMDV) serotype A were produced by fusing SP2/0 myeloma cells with splenocyte from the mouse immunized with A/AV88.The microneutralization titer of the mAbs 7B11 and 8H4 were 1024 and 512,respectively.Both mAbs contain kappa light chains,the mAbs were IgG1.In order to define the mAbs binding epitopes,the reactivity of these mAbs against A Type FMDV,were examined using indirect ELISA,the result showed that both mAbs reacted with A Type FMDV.These mAbs may be used for further vaccine studies,diagnostic methods,prophylaxis,etiological and immunological research on FMDV.Characterization of these ncindicated that prepared anti-FMDV A mAbs had no cross-reactivity with Swine Vesicular Disease (SVD) or FMDV O,Asia1 and C Type antigens.Their titers in abdomen liquor were 1:5×106 and 1:2×106,respectively.7B11 was found to be of subtype IgG1,8H4 was classified as IgG2b subtype.The mAbs prepared in this study,are specific for detection of FMDV serotype A,and is potentially useful for pen-side diagnosis.

Preparation and Characterization of Monoclonal Antibodies against VP1 Protein of Foot-and-mouth Disease Virus O/China99

Monoclonal antibodies (McAbs) 1A9 and 9F12 against Foot-and-mouth disease virus (FMDV) serotype O were produced by fusing SP2/0 myeloma cells with splenocyte from the mouse immunized with O/China99. Both McAbs reacted with O/China99 but not with Asia 1, as determined by immunohistochemistry assay. The microneutralization titer of the McAbs 1A9 and 9F12 were 640 and 1 280, respectively. Both McAbs contain kappa light chains, but the McAbs 1A9 and 9F12 were IgG1 and IgM, respectively. In order to define the McAbs binding epitopes, the reactivity of these McAbs against VP1, P20 and P14 were examined using indirect ELISA, the result showed that both McAbs reacted with VP1 and P20. McAbs may be used for further studies of vaccine, diagnostic methods, prophylaxis, etiological and immunological researches on FMDV.

Selection of Highly Susceptible Cell Lines to Foot and Mouth Disease Virus Infection

Different non-established cultures were examined to find those that showed high sensitivity to Foot and Mouth Disease Virus (FMDV). Ovine kidney cultures showed high sensitivity to types A, O and C, and were suitable to detect viral infection in samples of animal, as well as cell culture origin. The level of detection in this system was up to ten times higher than in BHK21 cells, which were commonly used for FMDV isolation and production. Viral production levels in ovine kidney cultures ranged from similar to twice as high as in BHK21. Ovine kidney cultures maintained these characteristics for at least 18 passages, allowing their use as an alternative system for FMDV diagnoses.

重组伪狂犬病病毒TK^-/FMDV VP1的构建

以伪狂犬病病毒 (PRV)为载体表达其他病原体抗原蛋白是伪狂犬病疫苗研究的一个重要方向。本文以广东地方分离株 (以下简称YA)为亲本株 ,用PCR方法得到同源左右臂 ,然后将重组转移载体和PRVYA的基因组共转染 ,用BUDR筛选出了表达口蹄疫病毒 (Foot_and_MouthDiseaseVirus ,FMDV)结构蛋白VP1的TK_重组病毒 ,用PCR和SDS -PAGE的方法对VP1蛋白进行了初步鉴定 。

FMDV OH99株基因组全序列的测定及其基因特征研究

采用RT-PCR方法对FMDV OH99株基因组全序列进行了分子克隆与测序。结果表明OH99株基因组全基因组序列长8040nt,其中5’NCR长1026nt,前导蛋白(L)编码区长603nt。该毒株结构蛋白与非结构蛋白编码区的核苷酸序列为6318nt,3’NCR长93nt,其后是poly(A)尾巴,测序结果表明该结构至少含有56个A。应用分子生物学软件,将OH99株与其它参考毒株进行了序列比较,并对其基因特征、推导的氨基酸序列进行了研究分析。结果显示,在分类地位上OH99株归属于O型FMDV,与OTY TW/97具有较高的同源性,而与其他参考毒株的差异性比较大,而且在基因组功能未知区域和3A编码区域具有两处明显的基因片段缺失现象,其中3A编码区缺失30nt,与OTY TW/97株相同,但功能未知区域的缺失状况与OTY TW/97稍有差异。根据VP1基因序列,对OH99株与参考毒株进行了系统发生树分析,分析结果表明OH99株与OTY TW/97株在同一基因型内,其遗传关系最近,而与其毒株遗传关系较远。

FMDV、BTV、PPRV多重RT-PCR检测方法的建立

为建立能够同时检测并鉴别口蹄疫病毒(Foot-and-mouth disease virus,FMDV)、蓝舌病病毒(Bluetongue virus,BTV)和小反刍兽疫病毒(Peste des petits ruminants virus,PPRV)感染的多重RT-PCR(反转录-聚合酶链式反应,Reverse transcription-polymerase chain reaction)方法,根据3种病毒的基因组全序列和保守区序列设计3对特异性引物,优化反应体系和扩增条件,建立能够同时检测3种病毒的多重RT-PCR方法。结果表明,建立的多重RT-PCR检测方法敏感性强,对FMDV、BTV和PPRV的核酸最低检测量分别为15.42、6.29、16.50ng/μL;特异性试验结果表明所建立方法的特异性良好。建立的多重RT-PCR方法具有敏感性高、特异性强、重复性好、快速简便等特点,可以用于临床上3种病毒感染的诊断和鉴别。

FMDV抗原表位与hsp_(70)的融合表达及表达产物对小鼠的免疫应答

将人工合成的O型口蹄疫病毒主要表位基因与结核杆菌热休克蛋白70(HSP70)基因克隆入酵母表达载体pPICZαA中,以电穿孔法转化酵母菌X-33,用Zeocin平板筛选重组子,PCR鉴定后甲醇诱导表达。SDS-PAGE显示,其相对分子质量为89 000,表达量约为190 mg.L-1;免疫印迹分析证实表达产物具有免疫反应性。融合蛋白以皮下接种的方式对8只小鼠进行3次免疫,然后通过ELISA和MTT分别检测抗体水平和淋巴细胞增殖反应。结果表明,融合蛋白既能诱导细胞免疫应答,又能诱导体液免疫应答,其产生的抗体水平接近于常规灭活疫苗。MTT试验结果显示,融合蛋白的A570为0.381±0.072,灭活疫苗的A570为0.340±0.050,表明融合蛋白的细胞免疫应答水平高于后者。提示,hsp70作为分子佐剂在口蹄疫基因工程疫苗研究中具有很好的应用前景。

A、O型FMDV T/B细胞抗原表位融合基因合成及植物表达载体构建

人工合成A、O型FMDV的7个细胞表位基因,应用套叠PCR将其中5个T细胞表位基因融合为T,2个B细胞表位基因融合为B,分别克隆进pMD-18T载体,再利用同尾酶的酶切及连接构建了不同组合的克隆载体(pMD-BT/BTT),然后将克隆载体改造为中间载体(pMD-xsB/xsT/xsBT/xsBTT),最终获得4个重组植物表达载体(pBI-xsB/xsT/xsBT/xsBTT).这为进行热研2号柱花草遗传转化及进一步研究同型与异型FMDV之间多表位基因的不同融合方式的免疫效果奠定了基础,为口蹄疫可饲植物疫苗的应用研究提供借鉴.

靶向FMDV受体猪源整联蛋白α_V亚基基因抑制FMDV复制的最佳siRNA筛选

筛选靶向FMDV受体猪源整联蛋白αV亚基基因抑制FMDV复制的最佳siRNA。根据猪源αV mRNA序列,设计并合成siRNA,Lipofectamine 2000转染siRNA于PK-15细胞,利用qRT-PCR检测RNAi组(iαV-480、iαV-1719和iαV-2077)、空白组(Mock)和阴性对照组(Control)中αVmRNA表达情况;在转染siRNA12h后通过接种100TCID50,收集病毒液,测定TCID50,确定其抗病性变化。结果显示,瞬间转染PK-15后,与阴性对照组和空白组相比,3个RNAi组均不同程度抑制αV亚基基因表达,在24hiαV-480组在mRNA水平抑制90.1%,作用最明显。TCID50测定表明iαV-480组有较低的病毒滴度,说明其抗病性增加。针对猪源整联蛋白αV亚基基因的最佳siRNA的筛选成功,为深入研究干扰FMDV受体抗FMDV转基因路线奠定了基础。

牦牛FMDV持续感染分离株非结构蛋白P2的克隆及基因特征分析

以FMDV持续感染模型动物牦牛的食道/咽部分离物(O/P液)为反转录模板,用1对特异性引物扩增目的cDNA,然后与pMD18-T载体连接并转化JM109菌株,再经重组质粒电泳、PCR和EcoRⅠ酶切鉴定.序列测定和分析结果表明,分离株与China/99的同源性最高达93.4%,而与Akesu/58序列的同源性为90.3%;推导的氨基酸序列同源性分别为97.8%、96.7%.

A Simple and Rapid Colloidal Gold-based Immunochromatogarpic Strip Test for Detection of FMDV Serotype A

A sandwich format immunochromatographic assay for detecting foot-and-mouth disease virus (FMDV) serotypes was developed. In this rapid test,affinity purified polyclonal antibodies from Guinea pigs which were immunized with sucking-mouse adapted FMD virus (A/AV88(L) strain) were conjugated to colloidal gold beads and used as the capture antibody,and affinity purified polyclonal antibodies from rabbits which were immunized with cell-culture adapted FMD virus (A/CHA/09 strain) were used as detector antibody. On the nitrocellulose membrane of the immunochromatographic strip,the capture antibody was laid on a sample pad,the detector antibody was printed at the test line(T) and goat anti-guinea pigs IgG antibodies were immobilized to the control line(C). The lower detection limit of the test for a FMDV 146S antigen is 11.7ng/ml as determined in serial tests after the strip device was assembled and the assay condition optimization. No cross reactions were found with FMDV serotype C,Swine vesicular disease (SVD),Vesicular stomatiti svirus (VSV) and vesicular exanthema of swine virus (VES) viral antigens with this rapid test. Clinically,the diagnostic sensitivity of this test for FMDV serotypes A was 88.7% which is as same as an indirect-sandwich ELISA. The specificity of this strip test was 98.2% and is comparable to the 98.7% obtained with indirect-sandwich ELISA. This rapid strip test is simple,easy and fast for clinical testing on field sites; no special instruments and skills are required,and the result can be obtained within 15 min. To our knowledge,this is the first rapid immunochromatogarpic assay for serotype A of FMDV.