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1.
为了解牛病毒性腹泻病毒(BVDV)感染对干扰素(IFN)mRNA转录时相的影响,探讨宿主-病毒之间的相互关系,用非致细胞病变(noncytopathic,NCP)和致细胞病变(cytopathic,CP)型BVDV感染临床健康BVDV检测阴性的荷斯坦奶牛外周血单核细胞(PBMC),利用实时荧光定量PCR技术对感染后IFN-α、β、γmRNA转录水平的变化进行定量分析。结果表明,CP型和NCP型BVDV感染PBMC后,Ⅰ型IFN(IFN-α、β)均呈现出不同程度的转录水平上调,且差异极显著(P〈0.01);只有IFN-α在CP型BVDV感染后4,12h(P〈0.5)出现转录下调。IFN-γ在整个感染过程中均呈现出不同程度的转录水平上调,且差异显著(P〈0.05)。这表明2种生物型BVDV感染可引起PBMC中IFN mRNA转录水平升高。  相似文献   

2.
牛病毒性腹泻病毒致病机制研究进展   总被引:1,自引:0,他引:1  
牛病毒性腹泻(bovine viral diarrhea,BVD)和黏膜病(mucosal disease,MD)均是由牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)感染引发的传染病,严重威胁世界养牛业的发展。文章概述了BVDV分型及其分子生物学特征,并从急性感染、经胎盘或子宫感染、持续性感染和黏膜病4个方面总结了近期国内外BVDV致病机制的研究进展。根据序列保守性及是否致细胞病变可将BVDV分为两种基因型和两种生物型,其中,新发现的"HoBi"株归类为瘟病毒属。BVDV基因进化很快,基因组编码4种结构蛋白和8种非结构蛋白,编码蛋白在病毒的复制、翻译及在宿主致病过程中发挥重要作用。BVDV致病机制复杂,急性感染会造成病毒血症、繁殖障碍、免疫抑制等,急性感染牛发生腹泻的原因与BVDV感染胃肠道的肌层、黏膜下层并干扰肠道神经的正常功能相关,非致细胞病变型(NCP)BVDV是造成急性感染的病因。胚胎感染BVDV取决于病毒首次侵袭时胎儿在子宫内的生长阶段。NCP型BVDV具有抑制胎儿体内产生Ⅰ型干扰素的能力,致使该病毒在宿主中得以生存并形成持续性感染牛,当持续性感染牛再次感染与NCP型BVDV高度同源的致细胞病变型(CP)毒株时直接诱发黏膜病。两种生物型的产生是发生持续性感染和黏膜病的重要因素,NCP型可向CP型BVDV进行转化。本综述有助于发现控制BVD-MD传播的新途径,为消灭该病和新型疫苗的研制提供参考。  相似文献   

3.
为深入研究牛场中普遍存在的持续性感染,探讨不同生物型牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)转化的分子机制,本试验将致细胞病变型BVDV (CP型BVDV)和非致细胞病变型BVDV (NCP型BVDV)感染MDBK细胞,观察细胞变化,感染后12~72 h期间每间隔12 h收集1次细胞,同时对24、48 h收集的细胞进行转录组学分析。结果显示,不同生物型BVDV感染宿主细胞24 h后,与感染NCP型BVDV的细胞相比,感染CP型BVDV的MDBK细胞中上调差异表达的基因2 849个,下调差异表达的基因3 347个,48 h后,上调差异表达的基因2 933个,下调差异表达的基因2 831个。对差异基因的GO功能分析结果表明,差异基因参与的分子功能主要有催化活性、结合活性、酶调节活性、分子转导活性和蛋白结合转录因子活性等;Pathway显著性富集分析结果显示,差异表达基因主要参与细胞自噬、细胞凋亡、免疫调节因子等相关的信号通路。本试验结果可为进一步揭示病毒致病的分子机制、控制BVDV和研制其候选疫苗奠定基础。  相似文献   

4.
牛病毒性腹泻病毒间接ELISA方法的建立   总被引:1,自引:1,他引:0  
持续性感染和免疫耐受是牛病毒性腹泻病的重要特征,也是该病的防控难点.本试验将2种生物型的牛病毒性腹泻病毒(BVDV):致细胞病变(CP)型(BVDV OregonC24株)和非致细胞病变(NCP)型(BVDV Yak株),灭活、浓缩作为抗原,分别免疫家兔制备高免血清.同时,使用BVDV全病毒蛋白作为包被原,建立了检测BVDV的间接ELISA检测方法.本试验利用该方法对高免血清进行检测,探讨CP型BVDV与NCP型BVDV抗原免疫原性差异.结果显示,CP型BVDV的高免血清效价均比NCP型BVDV高免血清的效价高,平均高35%.结果表明,CP型BVDV的免疫原性优于NCP型BVDV,且CP型BVDV与NCP型BVDV的血清效价具有明显差异.这为在实践中疫苗毒株筛选及生产提供了理论指导.  相似文献   

5.
牛病毒性腹泻病毒生物型转化分子机制的研究进展   总被引:3,自引:0,他引:3  
从病毒基因与宿主细胞基因的重组、病毒基因的复制与重排、病毒基因的重复复制和序列插入、病毒基因的缺失和点突变几个方面阐述了牛病毒性腹泻病毒(BVDV)由非致细胞病变型(NCP)向致细胞病变型(CP)转化的分子变异机制。总结了前人对NCP型向CP型BVDV转化研究的结果,归纳了5种生物型转化形式,揭示了BVDV具有高变异性。  相似文献   

6.
抗CP型、NCP型牛病毒性腹泻病毒高免卵黄抗体的制备   总被引:1,自引:0,他引:1  
本研究采用致细胞病变(cytopathic,CP)型牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)标准毒和非致细胞病变(noncytopathic,NCP)型新疆优势毒株免疫产蛋鸡,用改良PEG法提取卵黄抗体(IgY),并对提取的IgY采用SDS-PAGE检测纯度,间接ELISA检测免疫后每隔7 d的抗体效价,并测定所得抗体对NCP型BVDV的中和效价。结果表明,用该法提取的IgY纯度较高;间接ELISA结果证明,经过4次免疫后,抗CP型BVDV的效价达到1∶32000,抗NCP型BVDV的效价达到1∶40000,3个月后再次检测,卵黄抗体效价未见明显下降。最后一次免疫14 d的抗体对NCP型BVDV的中和效价达到1×10-3。  相似文献   

7.
用猪生殖与呼吸综合征病毒(PRRSV)与猪圆环病毒2型(PCV2)共感染40日龄健康大白仔猪,利用实时荧光定量PCR技术对共感染仔猪肺泡巨噬细胞(PAM)共刺激分子CD80一CD86的mRNA转录水平进行了定量分析。结果表明,在感染后第3d和第7dCD80与CD86mRNA转录显著下调(P〈0.05),感染后第14dCD86mRNA转录水平仍低于未感染对照组。尽管CD80mRNA转录水平在第14d和第28d高于对照组,CD86mRNA转录水平在第28d高于对照组,两者在第42d均高于对照组,但无显著差异。证实,PRRSV和PCV2共感染可导致猪肺泡巨噬细胞的共刺激分子CD80-CD86基因转录在感染早期明显受到抑制,PAM的抗原呈递能力受到影响。  相似文献   

8.
牛病毒性腹泻病毒致病机制研究进展   总被引:1,自引:0,他引:1  
牛病毒性腹泻(bovine viral diarrhea,BVD)和黏膜病(mucosal disease,MD)均是由牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)感染引发的传染病,严重威胁世界养牛业的发展。文章概述了BVDV分型及其分子生物学特征,并从急性感染、经胎盘或子宫感染、持续性感染和黏膜病4个方面总结了近期国内外BVDV致病机制的研究进展。根据序列保守性及是否致细胞病变可将BVDV分为两种基因型和两种生物型,其中,新发现的"HoBi"株归类为瘟病毒属。BVDV基因进化很快,基因组编码4种结构蛋白和8种非结构蛋白,编码蛋白在病毒的复制、翻译及在宿主致病过程中发挥重要作用。BVDV致病机制复杂,急性感染会造成病毒血症、繁殖障碍、免疫抑制等,急性感染牛发生腹泻的原因与BVDV感染胃肠道的肌层、黏膜下层并干扰肠道神经的正常功能相关,非致细胞病变型(NCP)BVDV是造成急性感染的病因。胚胎感染BVDV取决于病毒首次侵袭时胎儿在子宫内的生长阶段。NCP型BVDV具有抑制胎儿体内产生Ⅰ型干扰素的能力,致使该病毒在宿主中得以生存并形成持续性感染牛,当持续性感染牛再次感染与NCP型BVDV高度同源的致细胞病变型(CP)毒株时直接诱发黏膜病。两种生物型的产生是发生持续性感染和黏膜病的重要因素,NCP型可向CP型BVDV进行转化。本综述有助于发现控制BVD-MD传播的新途径,为消灭该病和新型疫苗的研制提供参考。  相似文献   

9.
非致细胞病变(NCP)牛病毒性腹泻病毒(BVDV)可引起持续的潜伏感染和免疫抑制,但是具体的感染机制尚不清楚。采用RNA测序(RNA-seq)技术,以NCP BVDV感染牛单核细胞2h和24h的细胞为样本分别提取总RNA,并采用HiSeqTM2500高通量测序技术进行转录组测序,对获得的有效序列进行功能注释及相关生物信息学分析。结果显示,在感染2h后,筛选出差异表达基因9959个,其中4968基因表达上调;在感染24h后,筛选出差异表达基因7977个,其中4184的基因表达上调;进一步分析NF-κB信号通路的变化,结果显示,在感染后2h,与免疫反应或抗病毒活性相关的基因表达显著增加,到感染24h表达水平显著下降。变化显著的基因均与炎症、免疫、自噬和凋亡密切相关。研究建立的牛外周血单核细胞感染BVDV后差异表达基因数据库,丰富了BVDV与宿主之间的相互关系,为BVDV持续感染机制的研究奠定基础。  相似文献   

10.
为研究CD46分子在BVDV感染树突状细胞(DC)介导的免疫应答中的作用,本研究根据牛CD46基因保守序列设计3对短发卡RNA(shRNA)的正义、反义寡核苷酸链,以及3对乱序列作为阴性对照,将其退火后分别克隆至p LL3.7质粒载体中,获得CD46基因shRNA重组质粒后将其转染MDBK细胞。采用荧光定量PCR和western blot技术筛选最佳沉默CD46基因的shRNA重组质粒,将其和表达载体p VAX1-CD46转染新疆褐牛DC(MDDCs)后利用BVDV感染MDDCs,通过荧光定量PCR检测DC表型及其细胞因子mRNA转录水平。结果显示,与未转染细胞组相比,CD46基因过表达的MDDCs中CD40、CD80、CD86和MHC-II的mRNA转录水平均明显升高(p0.05);而CD46基因沉默的MDDCs中CD40 mRNA转录水平也明显升高(p0.05),CD86 mRNA转录水平变化不明显(p0.05),CD80和MHC-II的mRNA转录水平均明显下降(p0.05)。与未转染细胞组相比,CD46基因过表达组IL-10和IL-12 mRNA转录水平变化不明显(p0.05),而CD46基因沉默的MDDCs中IL-10和IL-12 mRNA的表达均明显下降(p0.05)。本研究从新的角度初步揭示了CD46分子对BVDV感染DC成熟、初始T细胞增殖和分化的影响,为解决DCs对BVDV的免疫抑制作用提供新的思路。  相似文献   

11.
通过构建猪共刺激分子CD80和CD86的缺失cDNA竞争分子,用竞争PCR技术定量检测了猪圆环病毒2型(PCV2)感染后猪肺泡巨噬细胞(PAM)中CD80和CD86的mRNA水平,分析了PCV2感染对猪共刺激分子CD80和CD86的mRNA表达的影响.结果显示,PCV2感染后,PAM中CD80和CD86的mRNA水平变化趋势一致,只是CD86的升降幅度更大.在PCV2感染后3d,CD80与CD86的mRNA水平下降至最低,随后迅速上升,至14d达到高峰,尔后快速下降,21d及以后恢复正常.本研究结果表明,PCV2初期可明显抑制猪共刺激分子CD80和CD86的基因转录.  相似文献   

12.
The prevalence of bovine viral diarrhoea virus (BVDV) biotypes and subgenotypes was determined from 131 BVDV positive samples from a diagnostic laboratory. The majority of the isolates were from Oklahoma; however, other states including Kansas, Texas, and Arkansas were represented. These BVDV samples were from submissions of 76 live animals and 55 necropsy samples. There were 131 BVDV samples represented by 117 noncytopathic (NCP), 11 cytopathic (CP) and 3 cases with mixed NCP and CP biotypes. The NCP isolates were more common (P < 0.05) than the CP and NCP/CP combination. The BVDV samples were segregated into three subgenotypes by differential PCR and sequencing of a viral genomic region, 5'-untranslated region (5'-UTR). There were more BVDV1b subgenotypes 60/131 (45.8%) than BVDV1a, 37/131 (28.2%) or BVDV2a, 34/131 (26.0%) (P < 0.05). The organ system involvement included the major categories such as respiratory, digestive, mixed/multiple organs, abortions, and persistent infections (PI). All three BVDV subgenotypes were found in persistently infected (PI) cattle and respiratory diseases, both major requests for BVDV diagnosis. Only one of the 131 viruses was genetically similar to the strains present in U.S. vaccines.  相似文献   

13.
Non-cytopathic bovine viral diarrhea virus (ncpBVDV) induces immune responses mediated by chemokines and interferon (IFN) stimulated genes (ISGs). Cultured bovine peripheral blood mononuclear cells (PBMC) from ncpBVDV-naïve cattle were used herein to demonstrate that BVDV infection modulates chemokine receptor 4 (CXCR4), CXCL12, IFN-I, ISGs and selected immune cell marker (CD4, CD8, CD14) mRNAs, and that these acute responses to viral infection are reflected in PBMC cultured with serum from heifers carrying fetuses persistently infected (PI) with ncpBVDV. Infection of PBMC with ncpBVDV increased IFN-β, ISG15, RIG-I, CXCR4, CXCL12, and CD8 mRNA concentrations after 32 h. Culture of PBMC with uterine vein serum from acutely infected heifers, inoculated with ncpBVDV during early gestation to generate PI fetuses, also increased the concentration of CXCR4, RIG-I and ISG15 mRNAs. In vitro PBMC treatment with ncpBVDV or uterine vein serum from acutely infected pregnant heifers activates chemokine, ISG and immune cell responses.  相似文献   

14.
A system for a reproducible in vitro restimulation of bovine viral diarrhea virus (BVDV)-specific cytotoxic T-cells (CTL) was developed. Lymphocyte cultures of BVDV-immunised cattle were stimulated with infectious BVDV isolate PT810 and recombinant bovine interleukin-2 for 12 to 25 days. A specific lysis of Concanavalin A-stimulated BVDV-infected autologous target cells was observed, whereas allogeneic BVDV-infected target cells were only marginally lysed as detected by flow cytometry. BVDV-specific lymphocyte transformation was further characterised by the expression of bovine lymphocyte activation antigens and bovine MHC class-II molecules. Secondary stimulation of CTL was influenced by in vitro production of BVDV-specific neutralising antibodies, which were secreted exclusively in BVDV-inoculated lymphocyte cultures of immunised cattle. These results demonstrate the presence of CTL in peripheral blood mononuclear cells (PBMC) of immunised cattle which can kill autologous BVDV-infected antigen-presenting cells after in vitro restimulation.  相似文献   

15.
The ability of bovine peripheral blood mononuclear cells (PBMC) to mount a proliferative response to bovine virus diarrhoea virus (BVDV) in vitro was examined. After culturing PBMC in the presence of a non-cytopathic strain of BVDV for 6 days, the magnitude of PBMC proliferation was measured as incorporation of radiolabelled thymidine, present during the last 18 h. Live, but not heat-inactivated, BVDV evoked a proliferative response of PBMC obtained from cattle seropositive to the virus. However, PBMC from seronegative or persistently BVDV-infected animals were not stimulated by BVDV. The presence of live BVDV did not alter the proliferative response of PBMC to stimulation with concanavalin A.  相似文献   

16.
The effect of bovine viral diarrhea virus (BVDV) infection in vitro on the interleukin-1 (IL-1) activity of bovine monocytes was studied. Supernatants from BVDV-infected monocytes suppressed IL-1-stimulated proliferation of mouse thymocytes and masked lipopolysaccharide-stimulated IL-1 activity of bovine monocytes in the mouse comitogen thymocyte assay. Suppression of mouse thymocyte proliferation was restored by the addition of IL-1. IL-1 inhibitory activity was induced both by the prototype variants BVDV/NADL cytopathic and BVDV/NY-1 noncytopathic and by BVDV variants isolated from persistently infected cattle. Suppressed IL-1 activity was also found in supernatants from monocytes from persistently infected cattle following infection with BVDV in vitro. No differences in levels of IL-1 mRNA synthesis were detected between BVDV-infected and uninfected monocytes by RNA-cDNA hybridization. These results suggest that infection of bovine monocytes with BVDV results in the production and/or activation of a soluble inhibitor of IL-1 activity.  相似文献   

17.
A method for in vitro production of antibodies to bovine virus diarrhoea virus (BVDV) by peripheral blood mononuclear cells (PBMC) was developed. The PBMC were cultured in microtitre plates coated with detergent-solubilized BVDV and the supernatants were tested in an enzyme-linked immunosorbent assay which detects IgG antibodies to BVDV. Following incubation of PBMC with an optimal concentration of pokeweed mitogen for 5 days, antibodies to BVDV were detected in culture supernatants of PBMC from immune cattle, but not in supernatants of PBMC from seronegative cattle, from persistently BVDV-infected cattle or from a 5-day-old calf that received BVDV antibodies via colostrum. This antibody-production assay may therefore be used as a tool to discriminate between passively acquired antibodies and those actively induced.  相似文献   

18.
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