免疫组化Envision法检测肺组织中猪圆环病毒抗原的研究

为了对猪圆环病毒Ⅱ型(PCV2)的早期诊断、临床诊断和流行病学调查提供技术支持,本试验制备了兔抗PCV2多克隆抗体,采用免疫组织化学Envision二步法对30例疑似PCV2病猪肺组织的病毒抗原进行定位、半定量检测.结果表明,试验制备的兔抗PCV2抗体具有高纯度和良好的特异性;Envision法可原位检测病猪肺组织PCV2抗原的分布,其抗原的阳性表达主要出现在肺巨噬细胞胞浆内;依据阳性细胞百分率,进行染色结果判断,检出阳性病猪16例,阳性检出率为53.37%.实验证明Envision法具有高敏感、低背景、快速简便的特点,可在兽医病理诊断中推广应用.     

间接免疫酶组织化学法检测猪繁殖与呼吸综合征病毒感染和抗原定位

以蔗糖密度梯度离心法提纯的猪繁殖与呼吸综合征（Porcine reproductive and respiratory syndrome,PRRS）病毒SC1株作为抗原,免疫家兔制备兔抗PRRS病毒IgG,成功建立了检测PRRS病毒抗原的间接免疫酶组织化学法。该方法只与PRRS病毒感染猪组织呈现阳性反应,与猪瘟病毒、猪细小病毒、猪伪狂犬病毒、猪乙脑病毒人工感染并致死仔猪的肝脏组织呈现阴性反应。用该方法检测PRRS SC-1株人工感染28日龄仔猪,在感染后7 d即可在肺门淋巴结、胸腺、扁桃体、十二指肠、肺、大脑和肾脏检测到PRRS病毒抗原。PRRS病毒抗原主要分布于胸腺和十二指肠感染细胞的胞浆内、肺门淋巴结小梁周围的淋巴窦和弥散的淋巴组织、扁桃体淋巴结的隐窝及其周边。该法具有特异、直观和敏感的特点,可用于PRRS病毒感染的实验室诊断、抗原定位及甲醛固定样本的回顾性诊断。     

2003年猪病诊断回顾

2003年我们对来自全国20多个省市310多个猪场的血清和组织器官样品进行了检测,共计检测样品数达2万多份次,门诊解剖病猪700多头,并到部分猪场现场临床检查和流行病学调查,现将我们对2003年规模猪场常见病的诊断结果(见表1)和建议防制对策总结如下,供大家参考。一、繁殖与呼吸综合征(PRRS)全年共有295个猪场送检,由于大部分猪场已认识到了PRR S免疫的重要性,都已选用了不同的疫苗进行了免疫。所以我们对PRR S的诊断以PC R检测抗原为主,共有121个猪场检测了PR RSV抗原,其中检出阳性场91个,阳性率75.2%。在部分送检猪场中,PRR S引起…     

犬瘟热病毒间接免疫酶组化检测方法的建立

为对犬瘟热病毒(CDV)进行组织定位检查,本实验利用犬瘟热抗CDV单克隆抗体(MAb),采用间接免疫酶组化法对6只人工感染的比格犬肠组织的病毒抗原进行定位检测。结果表明,利用犬瘟热抗CDV MAb建立的间接免疫酶组化方法具有较高的特异性和灵敏性,可原位检测病犬肠组织中CDV抗原的分布,其抗原的阳性表达主要在小肠绒毛和李氏隐窝的上皮细胞胞浆内,表明CDV主要侵害小肠的粘膜上皮组织。     

兔肝脏和肠道中戊型肝炎病毒抗原的检测及组织病理学观察

为探讨兔体内戊型肝炎病毒(HEV)的感染情况,本试验从河北某屠宰场采集了136例兔肝脏样品和101例肠道样品。采用免疫组织化学染色方法对上述样品中的HEV抗原进行了检测,同时应用H.E.染色和Mallory三色染色法对其病理形态学变化进行了观察。研究结果显示,136例肝脏中HEV抗原免疫组织化学阳性样品共有96例,阳性率为70.59%,101例肠道中HEV抗原免疫组织化学阳性样品共有79例,阳性率为78.22%。组织病理学观察可见肝脏和肠道均有明显的炎症变化。本研究结果表明,兔群中存在较高的HEV感染率。     

猪繁殖-呼吸综合征活疫苗对仔猪的安全性试验

本试验用猪繁殖-呼吸综合征（PRRS）活疫苗和国内分离的PRRS强毒CH—1a株接种PRRS阴性的断奶仔猪，分别在接种后的3、7、14d各剖杀1头，取各脏器分别做冰冻切片和病理切片观察。用间接免疫荧光法检测各脏器PRRS病毒的分布。结果表明，PRRS活疫苗在免疫初期，抗原主要分布在脾脏、淋巴结，其次是肾脏和肺脏，少见于肝脏和心脏，第14d时在脾、淋巴结和肾脏有一定量的抗原，而肺脏相比则数量很少，肝脏和心脏未检到PRRS病毒抗原的存在，表明接种PRRS活疫苗随着时间的推移抗原分布呈下降趋势。而强毒抗原分布以脾脏最多，依次是肾脏、肺脏、淋巴结、肝脏、心脏，接种后第14d仍能在各脏器检到PRRS病毒抗原。病理组织学检测结果表明，活疫苗产生以下颌淋巴结、脾脏增生为特征的免疫应答，组织损伤轻微，对肺的病变较少，且仔猪生长良好。强毒则引起以大面积的肺泡隔增宽为特点的间质性肺炎和微循环障碍的病理变化，淋巴小结、脾脏滤泡发生崩解与周围界限不清，个别淋巴细胞核浓缩，组织损伤严重。本试验表明弱毒疫苗对仔猪是安全的。     

免疫组化方法检测细小病毒在雏鹅体内分布规律研究

采用间接免疫酶组织化学染色法对14日龄雏鹅人工感染GPV后，不同时间段病毒抗原在体内的定位及分布情况进行了检测。同时应用图像分析软件对抗原染色强度进行了定量分析。结果显示感染后第1天到第21天的不同时问点分别可以从心脏、肺脏、脾脏、肝脏、法氏囊、胸腺、腺胃、十二指肠、空肠、回肠、盲肠和食管十二种组织器官检测到病毒抗原。其中感染第5天感染组织最广泛，抗原染色强度最强，在检测的组织中空肠的检出率最高。病毒抗原广泛分布于肠道的上皮细胞、腺上皮细胞、肺泡壁细胞和’肾小管的上皮细胞内，可见上皮细胞为GPV抗原的主要靶细胞。本试验始终未能从大脑、胰腺和骨骼肌检测到GPV。     

免疫组化方法检测细小病毒在雏鹅体内分布规律研究

采用间接免疫酶组织化学染色法对14日龄雏鹅人工感染GPV后,不同时间段病毒抗原在体内的定位及分布情况进行了检测。同时应用图像分析软件对抗原染色强度进行了定量分析。结果显示,感染后第1天到第21天的不同时间点可以从心脏、肺脏、脾脏、肝脏、法氏囊、胸腺、腺胃、十二指肠、空肠、回肠、盲肠、食管十二种组织器官检测到病毒抗原。其中感染第5天感染组织最广泛,抗原染色强度最强,在检测的组织中空肠的检出率最高。病毒抗原广泛分布于肠道的上皮细胞、腺上皮细胞,肺泡壁细胞和肾小管的上皮细胞内,可见上皮细胞为GPV抗原的主要靶细胞。始终未能从大脑、胰腺和骨骼肌检测到GPV。     

免疫组化方法检测细小病毒在雏鹅体内分布规律研究

利用免疫酶组织化学染色法将雏鹅进行人工感染GPV,在不同阶段病毒抗原在体内的分布状况具有不同的特点,采用影像学技术对其予以定量分析后,雏鹅于感染1～21 d可在各器官中检测到病毒抗原体,而其中在5 d时,感染分布较为广泛,因此抗原出现染色效应的最大,待检组织中空肠具有较高的检出率,而病毒抗原因此广泛存在消化道的各种上皮细胞中,由此可知上皮细胞为GPV重要的靶细胞。     

猪带绦TSOL18重组蛋白抗原在小鼠体内的分布及毒性

试验采用肌肉注射途径给18g左右的小鼠接种TSOL18重组蛋白抗原,利用免疫组织化学方法、ELISA方法、检测TSOL18表达蛋白在小鼠体内的分布及其抗体产生,并进行毒性分析研究。结果表明,3d后,心、肝、脾、肺、肾免疫组化均阳性;15d后除肾脏组织免疫组化检测TSOL18蛋白抗原疑为阳性外,所有内脏器官免疫组化检测TSOL18蛋白抗原均为阴性,而对照组在整个试验期间检测结果均为阴性。10d后用间接ELISA即可检测到抗体,28d抗体水平达到相对较高水平,说明重组TSOL18重组蛋白作为抗原具有良好的免疫原性。毒性试验表明重组TSOL18表达蛋白作为免疫抗原使用安全。     

Immunohistochemical detection of porcine reproductive and respiratory syndrome virus using colloidal gold.

Two cytopathic agents were isolated on porcine alveolar macrophages following inoculation with homogenates of lung tissues from pigs showing respiratory problems. These isolates were identified as porcine reproductive and respiratory syndrome (PRRS) virus isolates by indirect immunofluorescence using a PRRS virus (PRRSV) specific monoclonal antibody (MAb) and were designated as LHVA-92-1 and LHVA-92-2. Immunogold electron microscopy using a porcine PRRS positive serum pool and protein A-gold resulted in an intense labelling of aggregates of viral particles. Dark specific cytoplasmic staining of porcine alveolar macrophages infected with both virus isolates could be observed by immunogold silver staining (IGSS) using the specific MAb. This method proved effective in detecting PRRSV antigens in several ethanol-fixed tissues of piglets intranasally inoculated with the supernatants of macrophages infected with each isolate. Immunogold silver staining was also successfully used for the detection of PRRSV antigens on sections of formalin-fixed paraffin-embedded lung tissues and on frozen sections of lungs. The present results indicate that colloidal gold may be useful for the identification and immunohistochemical detection of PRRSV in tissues.     

Immunopathogenesis of porcine reproductive and respiratory syndrome in the respiratory tract of pigs

Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) impairs local pulmonary immune responses by damaging the mucociliary transport system, impairing the function of porcine alveolar macrophages and inducing apoptosis of immune cells. An imbalance between pro- and anti-inflammatory cytokines, including tumour necrosis factor-α and interleukin-10, in PRRS may impair the immune response of the lung. Pulmonary macrophage subpopulations have a range of susceptibilities to different PRRSV strains and different capacities to express cytokines. Infection with PRRSV decreases the bactericidal activity of macrophages, which increases susceptibility to secondary bacterial infections. PRRSV infection is associated with an increase in concentrations of haptoglobin, which may interact with the virus receptor (CD163) and induce the synthesis of anti-inflammatory mediators. The balance between pro- and anti-inflammatory cytokines modulates the expression of CD163, which may affect the pathogenicity and replication of the virus in different tissues. With the emergence of highly pathogenic PRRSV, there is a need for more information on the immunopathogenesis of different strains of PRRS, particularly to develop more effective vaccines.     

猪繁殖与呼吸综合征病毒致病机理的研究进展

猪繁殖与呼吸综合征(PRRS)是由猪繁殖与呼吸综合征病毒(PRRSV)引起的一种以妊娠母猪严重繁殖障碍及仔猪的呼吸道症状和高死亡率为特征的传染病。现已遍及世界各主要养猪国家和地区,成为危害养猪业最严重的传染病之一。作者就猪繁殖与呼吸综合征病毒致病机理方面的研究情况作一综述,为诊断技术、免疫机理研究、疫苗设计和疫病防制提供借鉴。     

Increase of CD163 but not sialoadhesin on cultured peripheral blood monocytes is coordinated with enhanced susceptibility to porcine reproductive and respiratory syndrome virus infection

Porcine reproductive and respiratory syndrome virus (PRRSV) has a restricted tropism mainly for porcine alveolar macrophages (PAMs), but not for peripheral blood monocytes (BMo) in vivo. Previous research showed that only a few BMo became susceptible to PRRSV infection after 1 day culture. Porcine sialoadhesin (PoSn) and CD163 are identified to be the two main PRRSV receptors for binding and internalization. Both receptors are not expressed on BMo, or only expressed at low levels, which may explain why PRRSV cannot infect them. The relationship of BMo differentiation/aging, PRRSV receptor level, and susceptibility to PRRS virus infection has not been thoroughly investigated. In this study, BMo were successfully cultured with pig serum plus L929 cell culture supernatant. Our results showed that both the mRNA and protein expression levels of PoSn were significantly increased after 5-day culture. The mRNA level of CD163 was enhanced more than 20-fold after 1-day culture; CD163-positive BMo increased dramatically from about 2% after 2h- culture to about 50% after 96-h culture. Furthermore, cultured BMo became much more permissive to PRRSV infection, and the percentage of PRRSV-infected BMo was at least the same as PAMs, if not higher, when infected with CH-1a, the first PRRSV strain isolated in China, or HV, a highly virulent strain. Three other PRRSV strains including VR2332, and two classical Chinese isolates could also infect cultured BMo as well. Most importantly, PRRS virus was successfully isolated from 14 of 15 antibody-positive serum samples using cultured BMo. These results suggest that the enhanced susceptibility of cultured BMo to PRRS virus is coordinated with increased CD163 expression, but less related to the delayed (day 5) increased expression of PoSn. Thus, cultured BMo could be an alternative choice for PRRS virus isolation and identification.     

猪繁殖与呼吸综合征活疫苗中病毒含量荧光定量PCR测定方法的建立及初步应用

为建立快速、敏感、特异的评价猪繁殖与呼吸综合征（PRRS）活疫苗中病毒含量的方法,根据GenBank中登录的猪繁殖与呼吸综合征病毒（PRRSV）基因序列设计合成了标准品引物和定量引物,RT-PCR扩增PRRSV基因片段并连接到pMD19-T载体上,构建标准品质粒pMD19-T-PRRSV。采用SYBR GreenⅠ染料法进行荧光定量PCR检测,分析标准曲线并进行特异性、稳定性、重复性试验。结果显示,该方法检测病毒含量为7.43×10⁰～7.43×10⁸拷贝/μL,标准品各稀释度质粒拷贝数与Ct值之间相关系数高(R²=0.9989),引物特异性强。应用该方法对6个厂家PRRS活疫苗中的病毒含量进行测定,发现不同厂家生产的疫苗中病毒含量差异较大,最高差异可达47.9倍。本试验建立的检测PRRS活疫苗病毒含量的荧光定量PCR方法可用于疫苗生产过程中及免疫动物前疫苗质量的评价。     

猪繁殖与呼吸综合征抗病育种研究进展

猪繁殖与呼吸综合征(porcine reproductive and respiratory syndrome, PRRS)是由猪繁殖与呼吸综合征病毒(PRRS virus, PRRSV)引起的一种高度接触性传染病，严重危害我国乃至世界养猪业。然而由于PRRSV抗原的多变性，目前包括疫苗接种、药物治疗等在内的防治措施效果不佳。因此，随着现代分子生物学技术的不断发展，基于基因编辑技术对猪PRRS的抗病育种逐渐发展起来。本文简述了PRRS的临床症状，重点回顾了国内外PRRS抗病育种研究进展，通过分析PRRS的致病机制，重点阐述了PRRSV受体及针对不同受体进行编辑的体内及体外抗病毒效果，以期为未来深入研究PRRSV致病机制、开发PRRS抗病品种提供理论依据。     

猪繁殖与呼吸综合征胶体金抗体检测技术的建立和初步应用

用胶体金标记纯化后的猪繁殖与呼吸综合征病毒(PRRSV)基因工程表达抗原,建立一种以微孔滤膜为固相载体,以红色胶体金为标记物的检测PRRSV抗体的胶体金免疫层析法(GICA).特异性交叉试验证明GICA检测PRRSV抗体有较高的特异性.与其他方法对比检测证实了其敏感性.生产了一批免疫胶体金试纸条,检测36份临床样本,其中30份经免疫胶体金试纸条及ELISA、免疫荧光检测均为阳性.猪繁殖与呼吸综合征免疫胶体金抗体检测技术的建立为检测猪繁殖与呼吸综合征病毒(PRRSV)抗体提供了一种快速简便的方法.     

Monitoring porcine reproductive and respiratory syndrome virus infection status in swine herds based on analysis of antibodies in meat juice samples

An indirect ELISA test was developed as a novel tool aimed at monitoring the herd infection status of swine herds. Meat juice samples from pig carcasses were analysed for the presence of antibodies against porcine reproductive and respiratory syndrome virus (PRRSV). A study of samples from herds with known PRRS status was undertaken. The PRRS status of the herds was evaluated based on the analysis of blood samples by another serological test (blocking ELISA) capable of differentiating between infection with PRRSV of the American type and European type. The specificity of the indirect ELISA test on meat juice samples was 0.98. The sensitivity of the test depended on the type of the PRRSV strain involved. The apparent prevalence in herds infected with the American type of PRRSV was 0.44. The apparent prevalence in herds infected with the European type of PRRSV was 0.64. Herd level sampling and herd level criteria for assessing the PRRS status of herds by the new test were developed. Herds were classified as PRRS negative or PRRS seropositive based on 10 meat juice samples collected randomly at slaughter throughout a 3-month-period. Herd PRRS status classification by the indirect ELISA was validated in 47 herds by collection of blood samples from the herds. Eighteen herds were classified as PRRS negative by both test systems. Twenty-nine herds were classified as PRRS seropositive by both test systems. Acceptable herd classification was achieved using this test.     

猪繁殖与呼吸综合征病毒传统毒株与变异毒株的鉴别诊断

从山东各地猪场采集了50份疑似猪繁殖与呼吸综合征(PRRS)感染的病料,采用RT-PCR技术扩增出PRRS病毒(PRRSV)的ORF7基因和Nsp2基因,并对Nsp2基因进行了序列同源性比较和遗传进化树分析,从RT-PCR阳性病料中进行病毒分离,然后应用Nsp2单克隆抗体对分离毒株进行鉴别诊断。结果表明,从8份病料中同时扩增出病毒的ORF7基因和Nsp2基因,序列分析显示其中6株病毒的Nsp2缺失30个氨基酸,与Nsp2单克隆抗体不发生反应,属于变异毒株;另外两株病毒的Nsp2未见氨基酸缺失,与Nsp2单克隆抗体发生特异性反应,属于传统毒株。序列同源性和系统进化分析表明,6株变异毒株与其他高致病性毒株亲缘关系很近,而与经典毒株的遗传距离较远。     

猪繁殖和呼吸猪扁桃体病综合征病毒引起理变化的研究

对感染猪繁殖和呼吸综合征病毒（PRRSV）对猪扁桃体病理学变化进行了试验研究。结果发现攻毒猪的4种扁桃体均有一定程度的组织病理学变化,具体表现为扁桃体上皮细胞坏死、脱落,结缔组织和上皮内淋巴细胞浸润,实质中部分淋巴细胞变性、坏死、破碎,淋巴小结不明显,淋巴窦内嗜酸性粒细胞浸润。试验表明PRRSV可以诱导扁桃体产生免疫应答,而过度的PRILSV感染除引起炎性细胞聚集外,还可造成淋巴结坏死性炎症的特征性变化。这一结果将为理解PRRSV同机体的免疫结构相互作用的机理和免疫防制等更深层次的研究奠定一定的理论基础。