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1.
血清1型马立克病病毒(MDV-1)感染引起的鸡马立克病(MD)一直以来被认为是研究病毒诱导肿瘤发生机制的理想模型。此前研究发现,MDV-1编码的miR-M4-5p是宿主癌基因miR-155的病毒同源物,从基因组中敲除miR-M4-5p可显著降低MDV-1的致病性和致瘤性,表明miR-M4-5p可能是MDV-1诱导肿瘤发生的重要调控因子。为进一步揭示miR-M4-5p的调控机制,以CEF细胞总RNA反转录产物cDNA为模板,利用hybrid-PCR技术构建了miR-M4-5p的候选靶基因文库。通过基因克隆、PCR鉴定及序列比对分析,获得128个候选基因序列,有73个基因的3′-UTR存在miR-M4-5p的潜在结合靶点,其中23个3′-UTR结合靶点与miR-M4-5p完全互补配对。通过双荧光素酶报告试验和qRT-PCR分析,对miR-M4-5p与3′-UTR的体内外相互作用以及候选靶基因的表达水平进行分析和验证,最终鉴定DPT、TMEM230和DCLK1为miR-M4-5p调控的宿主靶基因。本研究为后续进一步阐明miR-M4-5p在MD肿瘤发生中的调控机制奠定了重要基础。  相似文献   

2.
血清Ⅰ型马立克病病毒(MDV-1)编码26个病毒mi RNA,前期研究发现这些miRNA可能在鸡马立克病肿瘤发生中发挥重要调控作用。为研究MDV-1编码的miRNA基因miR-M31-3p在病毒感染及致病过程中的作用机制,本研究利用杂交PCR方法构建宿主cDNA文库,对与miR-M31-3p互作的宿主候选靶基因进行初步筛选,结果获得了49个候选靶基因。通过双荧光素酶报告试验证实miR-M31-3p与鸡GNPAT、TCF12、FIGNL1、CNDP2、MGST1和CD99L2的3'-UTR在体外存在相互作用。进一步通过q RT-PCR分析显示:过表达miR-M31-3p的CEF中,上述6个候选基因m RNA转录水平均显著下调;当MDV感染CEF时,除CD99L2之外的5个候选靶基因的转录水平均显著下调,而在mi R-M31-3p基因缺失的MDV株感染的CEF中这5个靶基因均正常转录。上述结果证实CNDP2、GNPAT、TCF12、FIGNL1和MGST1为与mi R-M31-3p互作的宿主靶基因。本研究为进一步揭示miR-M31-3p调控MDV感染宿主的致病机制奠定了重要基础。  相似文献   

3.
马立克病病毒编码的miR-M11-5p宿主靶基因的筛选与鉴定   总被引:1,自引:1,他引:0  
作为α疱疹病毒的重要成员,马立克病病毒(MDV)感染鸡可引起免疫抑制及快速发作的T细胞淋巴瘤,即马立克病(MD)。此前发现MDV基因组编码大量病毒miRNA,可能在病毒复制、潜伏感染及肿瘤发生中起重要作用。基因敲除miR-M11-5p可显著增强MDV致病性及致瘤性,表明其可能是MD肿瘤抑制因子。为进一步揭示miR-M11-5p介导的调控机制,本研究利用鸡胚成纤维细胞(CEF)总RNA的cDNA为模板,通过hybrid-PCR扩增miR-M11-5p的候选宿主靶基因片段,然后连接至pMD19-T载体、转化至E.coli JM109中构建cDNA文库。对文库菌落进行PCR鉴定、测序分析以及Blast序列对比,共获得77个候选宿主靶基因,其中37个miRNA结合靶点位于候选靶基因的3′-UTR中。进一步通过双荧光素酶报告试验、miR-M11-5p过表达以及RT-qPCR分析,最终鉴定鸡MAFB、LOC776816和RFX7为miR-M11-5p的宿主靶基因。本研究为进一步阐明miR-M11-5p在MDV肿瘤发生中的调控机制奠定了重要基础。  相似文献   

4.
马立克病病毒miR-M4-5p宿主靶基因cDNA文库的构建及鉴定   总被引:1,自引:1,他引:0  
马立克病病毒(MDV)是少数感染自然宿主后可诱发淋巴瘤的疱疹病毒之一,是研究肿瘤发生及发展的理想动物模型。目前已报道MDV可编码数十种miRNA,其中MDV-1编码的miR-M4-5p被鉴定为宿主细胞miR-155的同源物,由于miR-155与人类多种肿瘤性疾病密切相关,这意味着miR-M4-5p可能在MDV的致瘤过程中扮演重要角色。本研究旨在构建miR-M4-5p的宿主靶基因文库并进行初步鉴定。提取鸡胚成纤维细胞(CEF)总RNA,反转录合成cDNA,用hybrid-PCR扩增候选靶基因片段连接到pMD19-T载体,转化大肠杆菌JM109感受态细胞后挑选单克隆进行PCR鉴定及测序,通过BLAST比对分析,共获得88个宿主候选靶基因序列。优先选择miRNA结合靶点位于mRNA 3′-UTR且与miR-M4-5p种子序列(2~7nt)完全互补配对的29个候选靶基因,构建报告基因载体进行双荧光素酶报告试验,通过三轮双荧光素酶报告试验最终初步鉴定5个宿主靶基因:PRICKLE1、COLA、BCAT1、ANTXR1和TECPR1,为进一步揭示miR-M4-5p的分子调控机制奠定了重要基础。  相似文献   

5.
meq是鸡马立克病病毒(MDV)最重要的致瘤基因,在马立克病(MD)肿瘤发生中发挥关键作用。同时,它在疫苗株和强毒株之间具有明显的序列差异性。本文利用CRISPR/Cas9基因编辑技术,以MDV疫苗株CVI988/Rispens meq基因为靶点,设计合成gRNA,克隆构建pX459-gRNA质粒,转染CEF并感染CVI988/Rispens,然后对meq基因编辑的病毒噬斑进行克隆纯化,经过PCR扩增、测序分析及IFA鉴定,成功构建1株meq基因编辑的缺失毒株CVI988Δmeq-C7,为后续筛选和鉴定抗MD疫苗株MEQ单抗及鉴别诊断研究奠定了基础。  相似文献   

6.
miRNA是具有19~25nt长度的内源性非编码RNA,它通过与mRNA的3'非转录区域(3'-UTR)结合而影响蛋白质的合成,从而达到调控基因的作用。马立克氏病病毒(MDV)是一种可以导致禽类产生肿瘤性疾病的疱疹病毒,而miRNA作为基因转录后调控因子可以影响肿瘤形成过程。文章从MDV-1编码miRNA所处的位置,它们所作用的靶基因及监测它们在感染MDV的组织和细胞中的表达水平三方面阐明了miRNA与MDV-1的致瘤性有着重要的关系。  相似文献   

7.
meq是鸡马立克病病毒(MDV)最重要的致瘤基因,在马立克病(MD)肿瘤发生中发挥关键作用。同时,它在疫苗株和强毒株之间具有明显的序列差异性。本文利用CRISPR/Cas9基因编辑技术,以MDV疫苗株CVI988/Rispens meq基因为靶点,设计合成gRNA,克隆构建pX459-gRNA质粒,转染CEF并感染CVI988/Rispens,然后对meq基因编辑的病毒噬斑进行克隆纯化,经过PCR扩增、测序分析及IFA鉴定,成功构建1株meq基因编辑的缺失毒株CVI988Δmeq-C7,为后续筛选和鉴定抗MD疫苗株MEQ单抗及鉴别诊断研究奠定了基础。  相似文献   

8.
研究病毒内源性非编码小RNA(VmiRNA)的靶标基因,有助于阐释病毒和宿主的互作关系及制定对病毒的防控策略。利用Solexa高通量测序技术及生物信息学方法,从柞蚕核型多角体病毒(Ap NPV)基因组中筛选出VmiRNA成熟体MD5,在预测其作用的宿主靶基因基础上,通过GO数据库分析靶基因的功能。结果显示由Ap NPV的VmiRNA MD5调控的宿主靶基因涉及细胞组成、分子功能、生物学过程等生物学途径,主要参与细胞内的分子结合、酶催化和免疫反应,其中与柞蚕免疫相关的靶基因共有4个。实时荧光定量PCR检测柞蚕蛹经Ap NPV诱导处理后VmiRNA MD5在脂肪体内明显上调表达(与对照相比提高了8倍),而与宿主免疫相关的3个靶基因的表达水平明显下调。对VmiRNA MD5 5'端上游启动子序列结构的分析显示,其含有免疫相关转录因子GMCSF、p53等的结合位点。推测VmiRNA MD5可能参与调控宿主柞蚕免疫相关基因的表达。  相似文献   

9.
马立克氏病(MD)是由马立克氏病毒(MDV)引起的鸡淋巴组织增生性传染病,对养禽业危害巨大。MDV线性基因组末端具有与宿主鸡序列相同的端粒重复序列(TMR),这些TMR有助于在潜伏期将MDV基因组整合到宿主端粒区,从而使病毒终生留在宿主体内。整合到宿主端粒对于MDV致病及诱导肿瘤发生至关重要,也能够有效地重新激活整合的病毒基因组。除TMR外,MDV还编码端粒酶RNA亚基(vTR),其与鸡基因组中端粒酶RNA(chTR)具有88%的序列相似性。vTR在病毒生命周期的所有阶段高度表达,增强端粒酶活性并在MDV诱导的肿瘤形成中起重要作用。文章重点介绍MDV基因组TMR序列和TR基因的最新研究进展。  相似文献   

10.
为了研究马立克病(MD)火鸡疱疹病毒(HVT)疫苗接种和抗性选育对鸡马立克病毒(MDV-1)攻毒后羽囊中病毒载量的影响,选择普通霞烟鸡及其MD抗性品系,利用MDV-1攻毒后第7、14、21、28和35天(DPI)五次采集并分离的全部试验鸡的羽囊为材料,采用Real-time FQ-PCR技术对这些材料中meq基因进行绝对定量分析以确定其病毒载量,用来分析比较MDV-1在MD抗性/普通鸡及HVT疫苗免疫/HVT疫苗未免疫鸡体内的增殖情况。结果显示:1)从MD抗性对病毒载量的影响看,一方面,普通非免疫攻毒组(F组)的MDV-1含量于14、21DPI时显著(P0.05)高于MD抗性非免疫攻毒组(T组);另一方面,MD抗性免疫攻毒组(R组)的MDV-1含量总体上却和普通免疫攻毒组(G组)相当。2)从HVT疫苗免疫对病毒载量的影响看,一方面,MD抗性非免疫攻毒组(T组)的MDV-1含量于28DPI时显著(P0.05)高于MD抗性免疫攻毒组(R组);另一方面,普通非免疫攻毒组(F组)的MDV-1含量于14、21DPI时显著(P0.05)高于普通免疫攻毒组(G组)。3)从MD抗性协同HVT疫苗免疫对病毒载量的影响看,普通非免疫攻毒组(F组)的MDV-1含量于14(P0.05)、28(P0.01)、35(P0.05)DPI时显著高于MD抗性免疫攻毒组(R组)。结果表明,鸡MD抗性选育协同HVT疫苗接种可显著降低鸡羽囊的病毒载量,这将会降低MDV-1传播风险,并提高鸡的存活机会。  相似文献   

11.
Marek's disease (MD) is a highly contagious lymphoproliferative and demyelinating disorder of chickens. MD is caused by Marek's disease virus (MDV), a cell-associated, acute-transforming alphaherpesvirus. For three decades, losses to the poultry industry due to MD have been greatly limited through the use of live vaccines. MDV vaccine strains are comprised of antigenically related, apathogenic MDVs originally isolated from chickens (MDV-2), turkeys (herpesvirus of turkeys, HVT) or attenuated-oncogenic strains of MDV-1 (CVI-988). Since the inception of high-density poultry production and MD vaccination, there have been two discernible increases in the virulence of MDV field strains. Our objectives were to determine if common mutations in the major glycoprotein genes, a major lytic antigen phosphoprotein 38 (pp38) or a major latency/transformation antigen Meq (Marek's EcoRI-Q-encoded protein) were associated with enhanced MDV virulence. To address this, we cloned and sequenced the major surface glycoprotein genes (gB, gC, gD, gE, gH, gI, and gL) of five MDV strains that were representative of the virulent (v), very virulent (vv) and very virulent plus (vv+) pathotypes of MDV. We found no consistent mutations in these genes that correlated strictly with virulence level. The glycoprotein genes most similar among MDV-1, MDV-2 and HVT (gB and gC, approximately 81 and 75%, respectively) were among the most conserved across pathotype. We found mutations mapping to the putative signal cleavage site in the gL genes in four out of eleven vv+MDVs, but this mutation was also identified in one vvMDV (643P) indicating that it did not correlate with enhanced virulence. In further analysis of an additional 12 MDV strains, we found no gross polymorphism in any of the glycoprotein genes. Likewise, by PCR and RFLP analysis, we found no polymorphism at the locus encoding the pp38 gene, an early lytic-phase gene associated with MDV replication. In contrast, we found distinct mutations in the latency and transformation-associated Marek's EcoRI-Q-encoded protein, Meq. In examination of the DNA and deduced amino acid sequence of meq genes from 26 MDV strains (9 m/vMDV, 5 vvMDV and 12 vv+MDVs), we found distinct polymorphism and point mutations that appeared to correlate with virulence. Although a complex trait like MDV virulence is likely to be multigenic, these data describe the first sets of mutations that appear to correlate with MDV virulence. Our conclusion is that since Meq is expressed primarily in the latent/transforming phase of MDV infection, and is not encoded by MDV-2 or HVT vaccine viruses, the evolution of MDV virulence may be due to selection on MDV-host cell interactions during latency and may not be mediated by the immune selection against virus lytic antigens such as the surface glycoproteins.  相似文献   

12.
Marek's disease (MD) remains a serious problem in the production of poultry. The disease is caused by Marek's disease virus (MDV), and despite the ubiquitous use of vaccination to control losses, MD still affects poultry farming worldwide. The aim of this study was to develop a loop-mediated isothermal amplification (LAMP) method for the simple and inexpensive detection of MDV in feather tips of chickens. Two pairs of specific primers complementary to the meq oncogene of MDV were designed, targeting the sequence of the very virulent MDV strain, RB1B. Bst polymerase was used for the isothermal amplification of viral DNA at 65 C for 90 min in a water bath. The fluorescence signal was identified in MDV-positive samples after the addition of SYBR Green and ultraviolet (UV) illumination. The sensitivity of LAMP was 2 log 10 plaque-forming units (PFU)/ml of HPRS16 and 10(3) copies/il of plasmid containing the target gene (meq) and was equal in sensitivity to PCR amplification. Due to the use of three sets of primers, LAMP was highly specific for MDV-1 DNA. The developed LAMP technique is a rapid and simple tool for the specific detection of MDV in samples of feathers taken from live chickens. Since the use of thermocyclers is not necessary for LAMP assay, it can be conducted by small laboratories and even field veterinarians.  相似文献   

13.
In Marek's disease virus infection, feather follicle epithelium (FFE) constitutes the site of formation of infectious virus particles and virus shedding. The objective of this study was to characterize cellular and cytokine responses as indicators of cell-mediated immune response in FFE and associated feather pulp following immunization against Marek's disease. Analysis of feather tips collected between 4 and 28 days post-immunization (d.p.i.) from chickens vaccinated post-hatch with either CVI988/Rispens or herpesvirus of turkeys revealed that replication of these vaccine viruses started at 7d.p.i., peaked by 21d.p.i., and subsequently, showed a declining trend. This pattern of viral replication, which led to viral genome accumulation in feather tips, was associated with infiltration of T cell subsets particularly CD8+ T cells into the feather pulp area and the expression of cytokine genes such as interferon-gamma, which is an indication of elicitation of cell-mediated immune responses at the site of virus shedding.  相似文献   

14.
In a certain area of Shandong province, Marek's disease (MD) occurred in diseased chickens that had been vaccinated by turkey herpesvirus.In order to isolate the virus strain and detect the virus pathogenicity, agar diffusion test, cell culture and indirect immunofluorescence assay (IFA) were used to isolate the Marek's virus from chicken's blood and feather marrow.The isolated strain was adapted to grow in chick embryo fibroblasts (CEF).Genes involved in pathogenesis of MDV, such as meq, pp38 and 132 bp repeat sequence were amplified by PCR.The obtained sequences were compared with that of standard strains published in GenBank by DNAStar software.The results showed that pp38 gene of the SDAU-1 shared homology from 100% with standard virulent sequence.Analysis of 132 bp repeat sequence and meq gene sequences of the viral genome showed that the isolated virus belongs to the highly virulent MDV strains.  相似文献   

15.
山东省某地区鸡马立克氏病疫苗免疫鸡群暴发马立克氏病(MD),为分离得到致病毒株,检测其致病性,采用琼脂扩散试验、细胞培养和间接免疫荧光试验(IFA)等方法从发病鸡的血液及羽髓中分离到一株适应鸡胚成纤维细胞(CEF)生长的马立克氏病病毒。采用PCR方法扩增分离毒株的meq、pp38、132bp重复序列等病毒致病相关基因,所得序列用DNAStar软件与GenBank上登录的参考毒株进行比对分析。结果显示,该分离株SDAU-1的pp38基因与标准强毒序列同源性为100%,132bp重复序列的拷贝数及meq基因的变异均符合MDV强毒株的序列特征。  相似文献   

16.
应用鸭胚成纤维细胞(DEF)从曾免疫过CVI988/Rispens株疫苗的患马立克氏病(MD)肿瘤的三黄鸡中分离到一株马立克氏病病毒(MDV,命名为GXY2株。用禽肿瘤病聚合酶链式反应(PCR)鉴别诊断技术对患鸡的肿瘤组织病料及克隆纯化毒株的DEF培养物进行检测,结果均扩增到MDV-1强毒株的132-bpr特异性带和网状内皮组织增殖病病毒(REV)的长末端重复序列(LTR)。用基于抗MDV-1的gB蛋白单克隆抗体BA4、MEQ蛋白单克隆抗体3G12E6和抗REV的单克隆抗体11B118分别对毒株的培养物进行间接免疫荧光试验(IFA),结果样品只与抗MDV-1的单克隆抗体呈现阳性反应,而与抗REV的单克隆抗体呈现阴性反应。应用PCR技术扩增并测定了毒株的致瘤相关基因meq的核苷酸序列,并与其他MDV-1参考毒株的序列进行比较分析,结果发现其序列与我们之前分离鉴定的MDV-1野强毒株G2和YL040920高度同源。研究的结果表明,分离株GXY2为整合有REVLTR片段的重组MDV强毒株。  相似文献   

17.
影响马立克氏病毒感染的因素及疫苗免疫策略   总被引:1,自引:0,他引:1  
马立克氏病毒是高度细胞结合性、嗜淋巴组织的α疱疹病毒,其致病过程包括淋巴细胞的溶细胞感染和潜伏感染以及易感鸡体内CD 4 T细胞的致瘤性转化。宿主的遗传抗性、细胞免疫、体液免疫以及相关细胞因子和淋巴细胞等对M DV的感染过程有重要影响。针对M D肿瘤抗原的靶向免疫应答的保护性抗原分子和宿主细胞因子疫苗是今后疫苗研究的方向。  相似文献   

18.
J M Sharma 《Avian diseases》1987,31(3):570-576
Several oncogenic and non-oncogenic isolates of Marek's disease virus (MDV) were inoculated into embryonated eggs on embryonation day (ED) 16 to 18, and embryos or chicks hatching from inoculated eggs were examined for infectious virus and viral internal antigen (VIA) in lymphoid organs. There was no evidence of extensive replication of MDV in any of the embryonic tissues examined. Levels of VIA peaked 4-5 days after chicks hatched. This indicated that MDV remained inactive during embryonation and did not initiate pathogenic events until chicks hatched. Because HVT replicated rapidly in the embryo but MDV did not, in ovo inoculation of HVT simultaneously with oncogenic MDV or several days after MDV resulted in significant protection (P less than 0.025) of hatched chicks against Marek's disease (MD). Little protection was obtained if HVT was given simultaneously with MDV or after MDV to chicks already hatched. The relative susceptibility of the embryo to extensive replication of the vaccine virus but not the challenge virus apparently accounted for protection against MD in chicks hatching from dually infected eggs.  相似文献   

19.
Marek's disease virus serotype 1 (MDV-1) strains cause malignant lymphoma in chickens. MDV-1 has been previously reported to be widespread in white-fronted geese (Anser albifrons); however, the prevalence of MDV-1 in other wild birds has not been determined. In this study, we investigated the prevalence of MDV-1 in various wild birds in Hokkaido, Japan. The MDV-1 genome was widespread in geese and ducks, but was not detected in other birds. MDV-1 was detected in both sedentary and migratory species. These results suggest that, in Japan, MDV-1 is widespread in wild goose and duck populations, and that resident ducks may be significant carriers and reservoirs of MDV-1.  相似文献   

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