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1.
为阐明新城疫病毒(NDV)在感染宿主细胞后对宿主真核翻译起始因子以及相关调控通路的调节作用,本实验采用western blot检测NDV感染He La细胞早期真核翻译起始因子e IF4F的磷酸化水平以及Akt/m TOR/4E-BP1和p38/Erk/Mnk1调控通路的活化情况,同时用紫外线(UV)灭活的NDV进行对照试验。结果显示,NDV感染He La早期能够迅速诱导真核起始因子e IF4E的磷酸化,而UV灭活NDV作用的细胞则无此现象。通过对相关调控通路的检测发现,NDV在感染早期对e IF4E的磷酸化是通过激活p38/Erk/Mnk1通路实现的。此外,NDV感染还可以激活Akt/m TOR/4E-BP1通路,诱导e IF4E阻遏蛋白4E-BP1发生磷酸化并解离出e IF4E,从而促进e IF4F复合体的形成,确保真核翻译的进行。该结果对深入解析NDV与宿主之间的相互作用以及翻译相关信号通路参与调控病毒复制的机制具有重要意义。  相似文献   

2.
本研究旨在探讨表皮生长因子(EGF)调控猪小肠上皮细胞IPEC-J2中钠依赖Ⅱb型磷转运蛋白(NaPi-Ⅱb)表达的分子机制。试验分别用EGF受体酪氨酸激酶抑制剂(tyrphostin AG1478)、蛋白激酶A(PKA)抑制剂(H89)、蛋白激酶C(PKC)抑制剂(k4393)、p38抑制剂(SB203580)、细胞外信号调节激酶(ERK)抑制剂(PD98059)、c-Jun氨基末端激酶(JNK)抑制剂(anisomycin)与EGF共同处理IPEC-J2细胞,利用Western blot检测相关通路蛋白及目的蛋白(NaPi-Ⅱb)的表达水平。结果显示:相较于对照组,EGF处理后NaPi-Ⅱb表达水平显著降低(P0.05);相较于无抑制剂组,EGF受体、PKA、PKC、丝裂原活化蛋白激酶(MAPK)/p38、MAPK/ERK1/2、MAPK/JNK的特异性抑制剂处理IPEC-J2后,NaPi-Ⅱb表达水平显著提高(P0.05),其中添加MAPK/ERK1/2特异性抑制剂显著降低了MAPK/ERK1/2在Tyr204位点的磷酸化水平(P0.05),添加MAPK/JNK的特异性抑制剂显著降低了MAPK/JNK1/2/3在Thr183和Tyr185位点的磷酸化水平(P0.05),说明该2组抑制剂对该通路的抑制作用是通过降低上述位点的磷酸化水平实现的。本研究结果表明EGF受体、PKA、PKC、p38、ERK和JNK均介导了EGF调控IPEC-J2细胞中NaPi-Ⅱb的表达。  相似文献   

3.
HeLa细胞中泛素蛋白酶体系统对新城疫病毒复制的影响   总被引:1,自引:0,他引:1  
本文主要对细胞的泛素-蛋白酶体系统是否参与新城疫病毒(Newcastle disease virus,NDV)的复制过程进行了研究。用NDV感染HeLa细胞,对细胞样品进行Western blot实验,并检测细胞26S蛋白酶体的三种蛋白水解活性变化。同时使用多种泛素-蛋白酶体系统相关的抑制剂处理细胞并做NDV感染,测定细胞上清中病毒TCID50值,比较药物处理与DMSO处理对病毒增殖的影响。结果表明,HeLa细胞在感染NDV后,细胞内泛素化蛋白水平降低,而26S蛋白酶体的三种蛋白水解活性都显著升高;使用泛素-蛋白酶体系统抑制剂后NDV的增殖受到了明显的抑制,证明NDV在HeLa细胞内的增殖与细胞自身的泛素-蛋白酶体系统关系密切。  相似文献   

4.
试验旨在研究p38 MAPK和JNK通路在繁殖与呼吸综合征病毒(PRRSV)感染的猪肺泡巨噬细胞(PAM)中的作用。感染PRRSV后36 h,p38和JUK1/2逐渐被激活;感染后48 h,其磷酸化水平显著降低至基线。然而紫外线灭活的PRRSV不能引起这些应激活化蛋白激酶(SAPKs)的磷酸化,表明病毒侵入后的步骤才能激活这些激酶。单独用p38或JNK抑制剂处理,都能显著降低PRRSV的感染,导致病毒基因组和亚基因组RNA合成、病毒蛋白表达、子代病毒生产的显著降低。并且抑制SAPKs时,感染PRRSV的PAM细胞中细胞因子的产生会发生改变。本研究结果表明,p38和JNK信号通路在病毒复制中发挥关键作用,并可能在病毒感染时调节免疫应答。  相似文献   

5.
为探讨水产养殖中氟喹诺酮类药物残留对水生生物的毒性效应,本试验研究了盐酸恩诺沙星对蛋白核小球藻(Chlorella pyrenoidosa)的毒性作用。试验设置5个药物浓度组和1个试验对照组。结果显示,各药物浓度组对蛋白核小球藻的生长均有抑制作用,并且随药物处理浓度的增大,藻细胞的生长逐渐降低。叶绿素a、b含量随着盐酸恩诺沙星处理浓度的增大而下降。蛋白核小球藻在经过不同浓度的恩诺沙星处理96 h后,各组蛋白质含量均远远低于对照组,并且蛋白质含量随着恩诺沙星浓度的升高逐渐减少。超氧化物歧化酶(SOD)活力和膜脂过氧化产物MDA则随着恩诺沙星药品浓度的升高而升高。表明盐酸恩诺沙星对蛋白核小球藻的胁迫引起其可溶性蛋白质含量、超氧化物歧化酶(SOD)活力和膜脂过氧化产物MDA含量的变化。  相似文献   

6.
本研究旨在基于哺乳动物雷帕霉素靶蛋白(mTOR)信号通路探讨猪肠上皮细胞增殖和精氨酸(Arg)转运的调控机制。在含100或350μmol/L Arg的培养基中添加(10 nmol/L)或不添加(0 nmol/L)雷帕霉素(Rap),培养猪肠上皮细胞(IPEC-J2细胞)3 d后,对细胞活力、细胞周期以及Arg转运、增殖和凋亡相关通路基因和蛋白表达进行检测。结果表明:1)添加Rap极显著降低了G2期和S期细胞数量(P0.01),而提高Arg浓度有效缓解了Rap对细胞增殖的抑制作用;Rap通过激活磷脂酰肌醇-3-羟激酶(PI3K)-蛋白激酶(Akt)-B细胞淋巴瘤2(Bcl2)信号通路抑制细胞凋亡。2)添加Rap抑制mTOR信号通路后极显著提高了Arg摄取率(P0.01),极显著提高了100μmol/L Arg培养下细胞中阳离子氨基酸转运载体2(CAT2)的mRNA和蛋白表达量(P0.01);进一步试验证明蛋白激酶Cα(PKCα)-细胞外信号调节激酶(Erk)/cFos-CAT2信号通路可能是Rap促进CAT2表达,进而提高Arg摄取的重要通路。综上可知,Rap应激下猪肠上皮细胞增殖被抑制,提高Arg浓度能有效缓解Rap对细胞增殖的抑制作用;Rap通过调控PKCα-Erk/cFos-CAT2信号通路促进猪肠上皮细胞对Arg的摄取,且提高Arg浓度可促进细胞对Arg的摄取。结果提示,mTOR信号通路在调控猪肠上皮细胞Arg利用过程中发挥重要作用。  相似文献   

7.
副黏病毒磷蛋白,即P蛋白(phosphoprotein),富含丝氨酸和苏氨酸,在自然条件下磷酸化水平较高。副黏病毒P蛋白的磷酸化对病毒的转录和复制具有重要的作用,但新城疫病毒(Newcastle disease virus,NDV)P蛋白磷酸化位点及其功能依然尚不明确。本研究通过LC-MS/MS质谱对NDV La Sota病毒P蛋白的磷酸化位点进行了检测,鉴定了Ser56、Ser77、Thr78、Thr82、Ser164和Ser141六个磷酸化位点。通过在线分析,预测这些磷酸化位点的磷酸化激酶分别是PKC、CKII和GSK3。为了鉴定6个磷酸化位点的生物学功能,在已建立的表达GFP基因的NDV微型基因组质粒pTVT-LGT基础上,用荧光素酶报告基因(luciferase)替换GFP报告基因,建立了表达荧光素酶的NDV微型基因组系统。利用"丙氨酸扫描"对6个磷酸化位点进行突变后,在NDV微型基因组平台中进行功能鉴定。结果显示,T78、T82和S164位磷酸化位点的缺失显著影响了病毒RNA依赖性RNA聚合酶复合体(RNA dependent RNA polymerase,RdRp)的复制,其生物学意义有待进一步的研究。  相似文献   

8.
石香薷挥发油体外抗病毒作用研究   总被引:3,自引:0,他引:3  
采用有机溶剂法提取了石香薷挥发油,采用体外细胞培养的方法研究石香薷挥发油对新城疫病毒(NDV)感染的拮抗作用,测定其对鸡胚成纤维细胞的最大无毒浓度(TDo)、半数细胞中毒浓度(TD50)、抑制50%细胞病变的药物浓度(IC50)、治疗指数(TI)及体外抗NDV效果。试验结果表明:石香薷挥发油的TDo、TD50、IC50、TI分别为1.56g/l、3.13g/l、0.20g/l、15.65,石香薷挥发油0.79g/l对NDV所致的CPE有明显的抑制作用,证明石香薷挥发油具有明显的抗NDV作用,提示石香薷挥发油可以作为一种新的抗NDV感染的药物。  相似文献   

9.
基质蛋白(M)是新城疫病毒(NDV)重要的结构蛋白。为监测NDV感染后M蛋白在细胞中的动态分布,本研究利用反向遗传操作技术,在NDV La Sota株全长c DNA中M基因编码区的C端插入由18个核苷酸编码的TC (Tetracysteine)标签,转染细胞经筛选获得携带TC标签的重组病毒La Sota-M-CTC。生长曲线测定结果显示,La Sota-M-CTC能够在鸡胚中有效复制,其生长曲线与亲本病毒La Sota相似。通过接种鸡胚测定鸡胚平均死亡时间检测La Sota-M-CTC的毒力。结果显示,La Sota-M-CTC的毒力与La Sota基本一致。此外,TC标签能够在重组病毒中稳定存在。将La Sota-M-CTC感染的细胞用双砷绿色染料FlAsH-EDT2染色后经激光共聚焦检测M蛋白在细胞中的分布。结果显示,在La Sota-M-CTC感染细胞后1 h~2 h时,M蛋白主要分布于细胞质中,而在病毒感染4 h后M蛋白进入细胞核中,并持续存在至病毒感染后的12 h。本研究为监测M蛋白在NDV感染过程中的动态分布以及阐明M蛋白在NDV感染中的作用机制提供了实验依据。  相似文献   

10.
为探讨板蓝根和黄芪提取液对新城疫病毒(NDV)的作用,通过分别测定将药液和病毒感作后接种于9日龄鸡胚、先接种药液再接种病毒和先接种病毒再接种药液3种不同的方式对NDV血凝效价的影响.研究了不同浓度板蓝根和黄芪提取液对NDV在鸡胚上增殖的影响。试验结果表明:不同浓度提取液在中和作用、阻断作用、抑制作用三个方面对NDV均有一定的效果.且药液抑制NDV感染力的作用强弱与药物的浓度和药物与病毒的作用方式均有关系。  相似文献   

11.
本研究对分离自上海某养鸡场的疑似鸡传染性支气管炎病毒(Infectious bronchitis virus,IBV)进行了分离和鉴定.所采用的方法有:鸡胚致病性试验、对鸡新城疫病毒(Newcastle disease virus,NDV)的干扰试验、动物回归试验以及RT-PCR鉴定等.试验结果表明,该病原接种鸡胚后,48 h可引起鸡胚死亡,胚体呈侏儒样变化,对NDV感染有明显干扰作用;用分离的病毒接种SPF雏鸡可产生明显呼吸道症状,肾脏表现肿大和大量尿酸盐沉积等病理变化;用IBV特异性引物可以从分离物中扩增出IBV的N基因序列,测序结果表明,该毒株属于肾型IBV.综上所述,本研究在上海流行区域成功分离到一株IBV,将其命名为SH11株.  相似文献   

12.
为了解目前中国新城疫病毒(Newcastle disease virus,NDV)优势基因VIId型的毒力机制,应用反向遗传技术将我国优势流行基因VIId型强毒株I4的F基因替换弱毒LX的F基因,获得表达NDV强毒株I4F基因的重组病毒NDV/LX-If。测定重组病毒的致病指数和组织分布,结果发现,重组病毒NDV/LX-If毒力比骨架病毒有了显著的提高。NDV/LX-If的鸡胚平均致死时间(mean death time,MDT)为56 h,雏鸡脑内接种致病指数(intracebral pathogenicity index,ICPI)为1.49,属于中等毒力,毒力比亲本病毒毒力低,但都能使自然途径感染的鸡100%死亡,同时获得了亲本毒株的组织嗜性。可见,新城疫病毒F基因是毒力和组织嗜性的主要决定因素,但是其它基因对新城疫病毒的毒力也可以产生影响。  相似文献   

13.
SUMMARY Experiments were conducted with vaccines containing the V4 strain of Newcastle disease virus (NDV). Both living aqueous vaccines and vaccines consisting of virus incorporated in an oil emulsion were used. The calculated dose of virus contained in the oil emulsion vaccine was 108,7 50% embryo infectious doses (EID50) per bird dose. Haemagglutinin inhibition (HI) antibody levels of 8 are presumed protective. One-day-old chicks with low levels of maternal antibody were vaccinated intraocularly with 106,3EID50 of live vaccine, and concurrently with oil emulsion vaccine. Presumed protective levels of antibody were present at two weeks post vaccination and were maintained for at least seven weeks longer. When adult birds 15 weeks old with no previous exposure to NDV were vaccinated intraocularly with 106,7EID50 per bird, protective levels of antibody were produced within a week. Unvaccinated birds put in contact with the vaccinated birds produced similar antibody levels within 14 days. Revaccination with oil emulsion vaccine after antibody levels had fallen resulted in a rapid response with high levels of antibody. When antibody-free adult commercial birds with an unknown history of exposure to NDV were vaccinated intramuscularly with oil emulsion vaccine, high antibody levels were produced for at least 21 weeks. Concurrent intraocular inoculation with 107,0EID50 live virus did not enhance the response. Natural infection of unvaccinated birds occurred during the experiment. This was detected by the presence of HI antibody levels of short duration. When antibody-free commercial birds were inoculated intramuscularly with oil emulsion vaccine containing 106,0, 107,0, or 108,0EID50 per bird dose, 100% of birds inoculated with the highest dose produced presumed protective levels of antibody within two weeks, as compared with a 5-week delay when using the 107,0EID50 per bird dose.  相似文献   

14.
SUMMARY Sixty-eight breeder chickens, 4 to 12 months of age, were taken from Australian flocks that had been naturally infected with avirulent Newcastle disease virus (NDV) and transported by air to Malaysia. Nearly all the breeders had haemagglutination inhibition antibodies to NDV, at titres of from 2 to 128. Thirty-two were inoculated intranasally with an Asian, velogenic, viscerotropic strain of NDV and all survived this challenge. Thirty-six were exposed to contact infection with the same velogenic NDV and 2 died of Newcastle disease within 14 days. The levels of haemagglutination inhibition antibodies against NDV increased in the surviving breeders after challenge, reaching 2048 or greater in a few birds. Velogenic NDV was isolated from a cloacal swab from one clinically normal breeder 10 days after challenge by contact. Cloacal swabs taken 7 to 10 days after challenge from another 23 breeders yielded no NDV. Twenty-four broilers, 7 weeks of age, were also transported from Australia to Malaysia. All lacked detectable haemagglutination inhibition antibody to NDV and they were from a flock with no detectable antibody to NDV. Twelve were challenged with velogenic NDV intranasally and 12 were subjected to contact challenge. All broilers died of Newcastle disease within 13 days.  相似文献   

15.
表达新城疫病毒HN基因的重组火鸡疱疹病毒的构建   总被引:1,自引:0,他引:1  
应用聚合酶链反应(PCR)技术,用设计带有限制性酶切位点的特异地扩增子人起始密码子开始的1.8kb新城疫病毒(NDV)血凝素-神经氨酸(HN)基因开放式阅读框(ORF),然后插入pTK2B的Nbe1位点,构建了含NDVHN基因的插入载体PTKHN1和PTKHN2,将其与感染火鸡疱疹病毒(HVT)细胞的总DNA共转民纤维细胞(CEF),经有限稀释法和Dot-blot筛选,得到含有HN基因的重组体rH  相似文献   

16.
为建立基于无血清悬浮培养细胞生产新城疫病毒(NDV)的工艺,本研究首先筛选了适于NDV增殖的乳仓鼠肾细胞(BHK-21)单克隆细胞株,并将鸡胚适应的NDV在筛选获得的细胞株(BHK-v002)中传代,获得细胞适应的NDV。进一步采用单因素实验法检测病毒感染复数(MOI)、TPCK-胰酶浓度、细胞培养液的稀释比例等工艺参数对病毒效价的影响。结果显示,NDV在无血清培养的BHK-v002细胞中增殖的最适条件为:当细胞生长至约9.0×10^6个/mL时,以培养液.新鲜培养基为2:1的比例补加新鲜培养基,使细胞密度达6.0×10^6个/m L,按MOI为0.005接种NDV LaSota株,TPCK-胰酶终浓度为5μg/mL。接种病毒后96 h收获病毒液的HA效价为8.5 log2HAU/25μL,单细胞产毒量(Svy)达到1 685.9病毒颗粒/细胞,半数组织细胞感染剂量(TCID50)为7.9 log10TCID50/100μL。本研究确定了NDV LaSota株在BHK-21细胞悬浮培养中的增殖条件,建立了基于BHK-21细胞无血清悬浮培养体系中NDV的生产工艺,该工艺操作简便,易于放大,为当前ND疫苗的鸡胚生产工艺提供了候选替代方案。  相似文献   

17.
应用RT-PCR获取新城疫病毒F48E8株的部分囊膜糖蛋白基因片段。扩增产物经琼脂糖凝胶电泳分析,长为926bp,与预期结果相符;将该基因片段定向克隆入质粒载体PUC19只,得到重组质粒P926,酶切分析结果与已发表的NDV毒株酶切位点一致。  相似文献   

18.
Establishment of selective immunity, local or systemic, made it possible to evaluate the pathogenesis of Newcastle disease virus (NDV) in the respiratory tract of chickens that were previously immunized with beta-propiolactone-inactivated antigen. NDV was inoculated intranasally or intramuscularly to chickens in different states of immunity (local or systemic). Humoral antibodies protected chickens against intranasal as well as intramuscular infection. Local antibodies, on the other hand, conferred immunity only against intranasal challenge. The respiratory tract supported multiplication of the virus, producing a self-limited subclinical infection. Replication of the virus in this system was negligible, playing only a minor role in the pathogenesis of the disease.  相似文献   

19.
D J King 《Avian diseases》1985,29(2):297-311
Three-to-seven-week-old broiler-type chickens were inoculated with Newcastle disease virus (NDV) by eye-drop (ED) or intratracheally (IT), and virus isolation was attempted from oropharyngeal (oral) swabs and medium harvested from tracheal explant cultures (TEC). The TEC were maintained in screw-capped tissue-culture flasks for at least 1 month, and medium harvested at regular feeding times was assayed for NDV and NDV antibody. The earliest and latest sample times were 3 and 21 days after NDV inoculation. The three experiments done were: Expt. 1, infection of nonvaccinates with NDV strain La Sota; Expt. 2, infection of NDV vaccinates and nonvaccinates with NDV strain Largo; and Expt. 3, infection of NDV vaccinates and nonvaccinates with NDV wild-type strain Kansas-Manhattan (KM) and two temperature-sensitive (ts) clones derived by J. S. Youngner from the KM strain. All experiments yielded similar results. On day 3 postinoculation (PI), most chickens were shedding virus recoverable by oral swabs and detectable in harvests from TEC prepared on that day. On day 7 PI, there was a sharp reduction in the frequency of virus-positive oral swabs, but there was no decline in the frequency of virus-positive TEC. On day 14 PI or later, all oral swabs and TEC were virus-negative, except for one chicken in Expt. 3 that was oral-swab-positive. There was no evidence of NDV persistence in the TEC of oral-swab-negative chickens on or after day 14 PI. The results of these experiments are in contrast with previous reports of the detection of latent NDV by virus isolation from harvests of TEC prepared 18 or more days PI. The ts clones of strain KM used in Expt. 3 induced a markedly poorer antibody response and were shed for a shorter time than the KM parental virus.  相似文献   

20.
为了阐明ERK(extracellular signal-regulated protein kinases)1/2通路在传染性支气管炎病毒(Infectious bronchitis virus,IBV)复制过程中的作用以及双特异性磷酸酶6(dual specificity phosphatase 6,DUSP6)对ERK的反馈性负向调控在IBV复制过程中的作用。本研究通过Western blot、Northern blot检测发现:IBV感染Vero和H1299细胞可导致ERK1/2的磷酸化水平和DUSP6表达均上调;利用MEK1/2特异性抑制剂U0126处理病毒感染的细胞后,可明显下调ERK1/2的磷酸化,同时抑制病毒的增殖;利用DUSP6的特异性抑制剂BCI抑制DUSP6的活性或者用siRNA阻断DUSP6的表达后,再感染IBV,发现ERK1/2的磷酸化水平增高,病毒蛋白的表达上调。综上,推测IBV感染细胞激活ERK1/2信号通路,有助于病毒的复制,同时,细胞通过诱导表达DUSP6,负向调控ERK1/2的磷酸化水平,抑制病毒增殖。  相似文献   

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