猪瘟病毒E0蛋白的原核表达及多克隆抗体的制备

为表达猪瘟病毒E0蛋白并制备其多克隆抗体,本研究构建E0蛋白的原核表达载体,转化至BL21(DE3)菌株,IPTG诱导表达,亲和层析及切胶回收纯化重组蛋白。SDS-PAGE和Western blot分析显示E0重组蛋白主要以包涵体形式表达,亲和层析纯化获得了E0重组蛋白,用其免疫Balb/c小鼠4次制备E0重组蛋白的多克隆抗体。间接ELISA显示,免疫小鼠血清中E0蛋白抗体效价为1∶50 000。获得的E0蛋白多抗能与病毒感染细胞及E0-EGFP融合表达细胞中天然结构的E0蛋白发生特异性反应。本研究制备的E0重组蛋白及其多克隆抗体为进一步研究E0蛋白的功能和免疫原性奠定了基础。     

马尔堡病毒糖蛋白RBD基因的原核表达、纯化及多克隆抗体的制备

原核表达并纯化马尔堡病毒(Marburg virus,MARV)糖蛋白(glycoprotein,GP)受体结合域(receptor binding domain,RBD)蛋白,并以此为抗原免疫家兔制备抗MARV-GP-RBD多克隆抗体。参照GenBank提供的MARV GP全基因序列,找到主要抗原表位区域,设计特异性引物,采用PCR方法扩增RBD基因,扩增产物经双酶切(EcoRⅠ/XhoⅠ)后定向克隆至原核表达载体pET-30a(+),构建重组表达质粒pET-30a(+)-GP-RBD,转化BL21(DE3)感受态表达宿主菌,在不同条件下(时间、IPTG浓度、温度)诱导表达目的蛋白,并用His-Band N+柱进行亲和层析纯化;以纯化的重组pET-30a(+)-GP-RBD蛋白免疫家兔,制备多克隆抗体。通过SDS-PAGE、Western blot和IFA鉴定重组蛋白的反应原性及免疫原性。结果显示:PCR扩增到长度为453bp的RBD基因片段;构建的重组质粒pET-30a(+)-GP-RBD经双酶切后得到与目的片段长度相同的特异性条带,测序结果显示没有突变;转化产物在培养7h、终浓度为0.4mmol/L IPTG和37℃条件下能够充分诱导目的蛋白表达,得到相对分子质量为25 000的重组蛋白,主要以包涵体形式存在,BCA试剂盒产量测定,每升诱导的重组菌可纯化约20mg纯度较高的目的蛋白;Western blot检测证实重组pET-30a(+)-GP-RBD蛋白能同时被抗His标签的单抗和兔源多抗识别并发生特异性反应,证明重组蛋白有良好的反应原性;IFA鉴定证实所制备的兔源多抗能够特异性识别表达MARV GP蛋白的重组杆状病毒rBacmid-GP-VP40,证明重组蛋白具有良好的免疫原性。结果表明:成功表达、纯化了MARV GP RBD蛋白,并完成了兔源多抗的制备,为MARV亚单位疫苗的制备和抗原、抗体检测方法的建立奠定基础。     

禽流感病毒NS2蛋白的原核表达及多克隆抗体的制备

为制备禽流感病毒(AIV)NS2蛋白的多克隆抗体,本研究将人工合成的NS2基因克隆至表达载体pET-28a中,转化大肠杆菌BL21(DE3),经IPTG诱导表达His-NS2重组蛋白。SDS-PAGE和western blot试验表明,该重组蛋白获得大量表达,可溶性高,并且具有较好的反应原性。将纯化后的重组蛋白免疫新西兰白兔制备多克隆抗体,并通过间接ELISA检测其效价达1∶20 000以上。Western blot和间接免疫荧光试验显示,多克隆抗体能够与NS2蛋白特异性结合。     

中国株马传染性贫血病病毒S2基因的原核表达及其多克隆抗体制备

本实验为表达马传染性贫血病病毒(EIAV)S2蛋白和制备其抗血清,以EIAV感染性分子克隆pFDDV3-8为模板扩增S2基因,将其克隆于pMD18-T载体中,测序验证后,将S2基因亚克隆于pET-30a表达载体,构建S2基因的重组表达质粒(pET-EIAV-S2),并转化DH5α受体菌.以终浓度为0.6 mmol/L的IPTG诱导,表达的重组蛋白约20 ku.Western blot分析表明,该蛋白可与EIAV的阳性血清反应,具有免疫原性.该重组蛋白通过镍离子亲和层析进行纯化后,免疫新西兰兔.ELISA及western blot分析表明,制备的兔多克隆抗体与EIAV的S2蛋白发生特异性反应.EIAV S2蛋白的重组表达及其抗体的制备为进一步研究S2辅助蛋白在EIAV复制与致病中的作用,以及S2基因反向遗传研究奠定了基础.     

口蹄疫病毒3B蛋白的表达纯化及其多克隆抗体的制备

为了深入研究口蹄疫病毒3B蛋白的结构及功能,本研究原核表达了3B蛋白并制备了针对3B蛋白的多克隆抗体。试验采用PCR方法扩增了口蹄疫病毒3B蛋白基因,并将其克隆到pET28a载体上,构建了重组质粒pET28a-3B,将其转化到大肠杆菌BL21感受态细胞中进行诱导表达。经过Ni-NTA琼脂糖亲和层析法初步纯化及Millipore超滤浓缩进一步纯化,将其免疫试验动物新西兰大白兔后制备出了抗3B蛋白的多克隆抗体。通过ELISA检测了该多抗的效价,Western blot试验检测了其反应性,通过间接免疫荧光(IFA)和Western blot试验检测了该多抗的应用性。结果表明:该抗体的效价为1∶512 000,反应性良好;IFA试验和Western blot试验中可以检测到过表达后定位于细胞核和细胞质中的3B蛋白,也可以检测到在真核细胞中过表达的3B蛋白。说明本研究制备的口蹄疫病毒3B蛋白多克隆抗体可以作为开展该病毒相关研究的重要材料。     

禽流感病毒蛋白AM2的表达、纯化及其多克隆抗体的制备

利用大肠杆菌BL21表达禽流感病毒蛋白AM2,分离纯化目的蛋白,进行小鼠免疫制备多克隆抗体。将A型禽流感病毒M2基因的原核表达重组质粒pGEX-6p-1-AM2转化大肠杆菌感受态细胞BL21,经IPTG诱导后,在大肠杆菌表达系统中获得表达,并分离纯化蛋白,制备抗原免疫动物,得到了pGEX-6p-1-AM2的多克隆抗体。经western-blot免疫印迹分析,自制的多克隆抗体能特异地与AM2蛋白相互作用,这说明试验制备了特异性良好的抗AM2的多克隆抗体。     

牛病毒性腹泻病毒E0蛋白的原核表达及多克隆抗体制备

【目的】应用大肠杆菌表达系统表达牛病毒性腹泻病毒(BVDV) E0蛋白,纯化后免疫小鼠制备E0蛋白多克隆抗体用于BVDV的检测技术研究。【方法】采用PCR扩增BVDV的E0基因,将其连接至pET-28a (+)构建重组表达载体pET28a-E0。将重组质粒转化大肠杆菌BL21感受态细胞,经IPTG诱导、亲和层析纯化后,通过SDS-PAGE和Western blotting鉴定E0蛋白的表达情况。将纯化的E0蛋白免疫小鼠制备BVDV E0多克隆抗体,并通过Western blotting、细胞免疫荧光试验、ELISA等试验检测该多克隆抗体的特异性和效价,以及在BVDV检测中的应用。【结果】成功构建原核表达载体pET28a-E0,表达并纯化E0蛋白,制备的BVDV E0多克隆抗体可特异性识别纯化的E0蛋白及pET28a-E0在BL21中表达的总蛋白。进一步Western blotting、细胞免疫荧光试验、双抗夹心法ELISA证明制备的E0多克隆抗体可用于BVDV的检测。间接ELISA结果表明,E0多克隆抗体效价高于1∶64 000。【结论】制备的BVDV E0多克隆抗体效价高、抗原结合特异性强,为BVDV E0蛋白的生物学功能研究及BVDV的检测提供了材料支持。     

马疱疹病毒1型UL56蛋白的原核表达及多克隆抗体的制备

为制备马疱疹病毒1型（EHV-1）UL56蛋白（pUL56）的多克隆抗体。该研究根据GenBank中EHV-1 YM2019株全基因组序列,采用Ni-NTA亲和层析纯化蛋白,与弗氏佐剂乳化后免疫BALB/c小鼠并制备pUL56多克隆抗体,经Western blot与间接ELISA试验测定多克隆抗体反应性。结果显示,纯化后的pUL56可以与EHV-1阳性血清发生反应;pUL56多克隆抗体的效价为1∶128 000,并能与pUL56特异性结合。本研究成功制备具有良好反应性的pUL56多克隆抗体,为pUL56功能特性及EHV-1致病机制的研究奠定理论基础。     

巴泰病毒N5aa-90aa重组肽段的原核表达纯化及多克隆抗体的制备

巴泰病毒(BATV)是一种虫媒病毒,属于布尼亚病毒科成员,其核衣壳N蛋白具有高度保守性,可诱导机体产生较好的抗体反应,常用做诊断抗原。本研究通过对N蛋白强抗原性肽段N_5aa-90aa进行密码子优化,将其插入到p ET-32a(+)载体,并转化到大肠杆菌BL21(DE3)感受态细胞中表达,通过不同IPTG浓度和诱导时间确定最佳蛋白表达条件。利用镍柱亲和层析方法对r His-N_5aa-90aa肽段进行纯化。通过Western blot对r His-N_5aa-90aa肽段进行验证,将r His-N_5aa-90aa肽段免疫新西兰白兔制备多克隆抗体,间接ELISA测定其抗体效价。结果显示：本研究成功构建了p ET-32a-N_5aa-90aa重组质粒,在IPTG终浓度为0.1 mmol/L、37℃诱导5 h可获得大量重组蛋白;SDS-PAGE电泳结果显示重组r His-N_5aa-90aa肽段分子质量约28.6 kDa,蛋白浓度为0.256 mg/mL;经Western...     

狂犬病病毒BD-06株基质蛋白的原核表达、纯化及其多克隆抗体的制备

本研究旨在获得抗狂犬病病毒M蛋白的多克隆抗体,为进一步研究M蛋白功能提供材料。本试验以狂犬病病毒BD06毒株为模板克隆M基因序列,将其克隆至原核表达载体pET28a;经酶切和测序鉴定,M蛋白基因序列已正确插入表达载体pET28a;以表达载体pET28a-M转化E.coli Rosetta株,并以0.5 mmol/L IPTG诱导,结果表达出27 ku左右的M蛋白;将诱导表达的蛋白质回收纯化,以纯化的M蛋白多次免疫兔子制备多克隆抗体;Western blotting分析和间接免疫荧光分析结果表明,制得的抗体与病毒能够反应,运用制得的多克隆抗体定位了基质蛋白在感染狂犬病病毒的BHK-21细胞中的位置。结果表明成功制得了抗狂犬病病毒M蛋白的多克隆抗体,为研究狂犬病病毒M蛋白功能奠定了基础。     

Tunicamycin enhances neuroinvasion and encephalitis in mice infected with Venezuelan equine encephalitis virus

Venezuelan equine encephalitis (VEE) viruses cause natural outbreaks in humans and horses and represent a significant biothreat agent. The effect of tunicamycin on the course of the disease in mice with VEE was investigated, and the combined effects of these agents was characterized. CD-1 mice given 2.5 microg of tunicamycin had >1,000-fold more virus in the brain 48 hours after infection with the virulent VEE strain V3000 and > or =100-fold of the attenuated strain V3034 at all tested times than did untreated mice, indicating enhanced neuroinvasion. Tunicamycin did not alter the viremia profiles of these viruses nor the replication of V3000 in the brain itself. Tunicamycin alone caused ultrastructural blood-brain barrier damage, yet neuroinvasion by V3000 in treated mice appeared to occur via the olfactory system rather than the blood-brain barrier. Tunicamycin-treated, V3000-infected mice also exhibited earlier and more severe weight loss, neurological signs, neuronal infection, neuronal necrosis and apoptosis, and inflammation than untreated, V3000-infected mice. The mean survival time of tunicamycin-treated, V3000-infected mice was 7.3 days versus 9.9 days for untreated, V3000-infected mice. These studies imply that animals that ingest toxins similar to tunicamycin, including the agent of annual ryegrass toxicity in livestock, are conceivably at greater risk from infections by encephalitis viruses and that humans and horses exposed to agents acting similar to tunicamycin may be more susceptible to encephalitis caused by VEE viruses. The exact mechanism of tunicamycin-enhanced neuroinvasion by VEE viruses requires further study.     

Venezuelan equine encephalomyelitis virus: Concentration,partial purification,inactivation and immunogenicity

Venezuelan equine encephalomyelitis (VEE) TC-84 vaccinal virus, from 10-1. quantities of infected duck embryo fibroblast cell culture fluids, was isolated by combined continuous-flow centrifugation with isopycnic banding in sucrose. Most of the recovered infectivity and hemagglutinating activity were in a single band at a buoyant density (?) of 1.2. About 90% of the total input protein (450–520 mg) was removed with the effluent, whereas most of the remaining 10% also banded at a ? of 1.2. Infectivity was inactivated with formalin at a final concentration of 0.05% at 37°C for 24 hr. Formalin-inactivated virus retained its immunogenicity and induced VEE virus-specific antibody in horses and guinea pigs. The horses and those guinea pigs that received equivalent doses of vaccine survived after a challenge of their immunity with virulent VEE virus.     

Cloning, expression and purification of envelope proteins E1 and E2 of western equine encephalitis virus and potential use of them as antigens in immunoassays

The genes encoding envelope proteins E1 and E2 of western equine encephalitis virus (WEEV) were respectively cloned into a prokaryotic T7 RNA polymerase-regulated expression vector. The recombinant C-terminal 6xHis-tagged WEEV E1 and E2 were expressed in bacteria as inclusion bodies that were subsequently solubilized with 8M urea, purified by immobilized metal ion affinity chromatography and finally refolded using an arginine system. The purified 6xHis-tagged proteins showed 50kDa bands as revealed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, consistent with the expected sizes of WEEV E1 and E2. The potential of the recombinant WEEV E1 and E2 as antigens for serologic tests to detect anti-WEEV antibodies for diagnosis of WEEV infection was assessed by an enzyme-linked immunosorbent assay with anti-WEEV polyclonal antibodies obtained from the mice infected with WEEV. The anti-WEEV antibodies bound the recombinant WEEV E1 and E2 in a dose dependent manner. On the contrary, antibodies against Venezuelan equine encephalitis virus with a genetic background and a disease spectrum very similar to WEEV, did not bind to the recombinant WEEV E1 and E2. Our results suggest that the recombinant WEEV E1 and E2 possess predominant antigenicity of WEEV and have the potential to be used as antigens in immunoassays to detect anti-WEEV antibodies for serological diagnosis of WEEV infection so as to eliminate the need for preparation of cell culture-derived viral antigens, which is time-consuming, expensive, laborious, tedious, and hazardous.     

抗东方马脑炎病毒结构蛋白E2单克隆抗体的制备及其抗原表位的鉴定

为制备抗东方马脑炎病毒(EEEV)结构蛋白E2的单克隆抗体(MAb)并鉴定其抗原表位,本研究以Bac-to-Bac真核表达系统表达EEEV E2蛋白,纯化后作为免疫原免疫BALB/c小鼠,取其脾淋巴细胞与小鼠骨髓瘤细胞SP2/0进行融合.以原核表达载体pET-30a表达并纯化的EEEV E2蛋白作为包被抗原建立间接ELISA方法筛选杂交瘤细胞,获得4株稳定分泌抗EEEV E2蛋白MAbs的杂交瘤细胞株,分别命名为6F3、6F11、7C11、8B11.Western blot与间接免疫荧光试验结果表明,获得的4株MAbs均与EEEV呈阳性反应,而与西方马脑炎病毒、乙型脑炎病毒以及登革热病毒1型～4型呈阴性反应.利用部分重叠的原核表达的短肽对E2蛋白抗原表位进行鉴定,初步确定MAb 6F11、7C11和8B11识别的抗原表位均为E-33 (321EGLEYTWGNHPPKRVW336),而MAb 6F3无短肽与其反应,推测可能为构象表位.本研究结果为建立EEEV型特异性检测方法、研究E2蛋白结构功能及该病的进一步防制奠定了基础.     

Pathogenesis of Venezuelan equine encephalitis virus infection in mice and hamsters.

The pathogenesis of Venezuelan equine encephalitis (VEE) virus infection was compared in intraperitoneally inoculated mice (n = 24, 6 to 8 weeks old) and hamsters (n = 9, 90-110 g) using histopathology and immunohistochemical localization of VEE virus antigen. Infected mice developed paralysis, and the majority died by 9 days after inoculation. In contrast, hamsters did not survive beyond 3 days after inoculation, and they did not develop any neurologic signs. VEE virus antigen, demonstrated by immunoperoxidase staining, and pathologic changes were present in extraneural organs of both mice and hamsters. There was more severe involvement in hamsters, particularly in Peyer's patches of the distal small intestine. There was a severe encephalomyelitis in mice, but pathologic changes were not well established in the brains of hamsters before death. VEE virus antigen was widespread in the central nervous system of both mice and hamsters. VEE virus was found to be highly neurotropic in hamsters and had a similar distribution in the brain as in mice, but hamsters died from their extraneural disease before major central nervous system disease developed.     

马动脉炎病毒GP5蛋白主要抗原域的表达及鉴定

在分析EAV-GP5蛋白抗原性的基础上,设计一对引物扩增GP5蛋白的主要抗原域编码EAV-GP5 79~330 bp。将扩增基因插入pET-30aBamHⅠ和HindⅢ间构建原核表达载体pET-GP5。将pET-GP5质粒转入BL21(DE3)宿主菌并优化诱导表达条件,实现马动脉炎病毒EAV-GP5蛋白主要抗原域的高效表达。重组pGP5经纯化制备兔抗pGP5免疫血清,经免疫印迹及间接免疫荧光试验鉴定,证实所得表达产物具有良好的免疫原性。     

西尼罗病毒糖蛋白第三结构域的原核表达及鉴定

根据西尼罗病毒(West Nile virus,WNV)序列设计1对特异性引物,用PCR反应扩增糖蛋白第三结构域(WNVEDⅢ)基因,将PCR产物克隆至pGEX-4T-1原核表达载体上,获得重组表达质粒,将该质粒转化入E.coli DH5α,命名为pG-EDⅢ,鉴定正确后转入transetta表达菌中,经IPTG诱导后纯化重组蛋白,通过SDS-PAGE和Western-blot方法证实WNV-EDⅢ基因可在大肠杆菌中高效表达,小鼠免疫试验证明该原核表达蛋白有良好的免疫原性。     

马疱疹病毒gD蛋白主要抗原域的表达及初步应用

根据GenBank马疱疹病毒1型(EHV-1)和4型(EHV-4)gD基因进行分析,选取同源性较高且抗原性强的C端序列设计一对引物进行扩增。将扩增的基因插入pET-30a的BamHⅠ和SalⅠ之间构建原核表达载体pET-gD。然后将pET-gD质粒转化至BL21(DE3)宿主菌,对培养和表达条件进行优化,实现EHV gD蛋白主要抗原区域的高效表达。将重组pET-gD蛋白进行纯化并接种长白兔制备高免血清。经免疫印迹试验鉴定,证实所得纯化表达产物具有良好的抗原性。