人IFN-γ体外释放检测法的建立及其在结核病诊断中的应用

本研究旨在建立人IFN-γ体外释放检测法,用于人结核病的特异性诊断.克隆表达了人IFN-γ基因,利用纯化的重组IFN-γ免疫小鼠,获得两株高效价的单克隆抗体.用所获得的单克隆抗体及兔抗IFN-γ多克隆抗体建立了检测人IFN-γ的夹心ELISA,检测灵敏度达到31.25 pg/mL.采集111位结核病阳性病人与292位临床健康对照者肝素抗凝全血,利用结核菌特异性抗原ESAT-6/CFP-10融合蛋白体外刺激外周血淋巴细胞释放IFN-γ,用所建立的夹心ELISA及商品化试剂盒平行检测所有样本,结果表明两种方法的检测结果相符.结核患者的检测灵敏度为95.5%,健康对照的阳性检出率为16.7%,患者与健康对照的阳性检出率差异极显著(P<0.01),证实所建立的方法灵敏度与特异性均很高,具有良好的应用前景.     

牛IFN-γ原核表达、单克隆抗体制备及其ELISA检测方法的建立

实验旨在建立牛重组IFN-γ(BovIFN-γ)的ELISA检测技术,为牛传染病的免疫学诊断提供新方法。PHA刺激体外培养的奶牛外周血白细胞,从培养细胞中提取总RNA,经过RT-PCR扩增出BovIFN-γ基因cDNA,进一步克隆至pET28a,转化大肠杆菌,经IPTG诱导,表达出预期大小(18kD左右)组氨酸标记蛋白,经鉴定为BovIFN-γ;以纯化的重组BovIFN-γ为免疫原,应用淋巴细胞杂交瘤技术,获得4株能稳定分泌抗BovIFN-γ单克隆抗体的细胞株,分别命名为A7、A10、G6与G10。免疫球蛋白亚类鉴定证明杂交瘤细胞所分泌的抗体均为IgG1,腹水效价在1∶210×100~1∶211×100之间。Western-blot分析显示,4株单抗均能特异性结合重组BovIFN-γ。ELISA试验表明,4株单抗只与融合蛋白BovIFN-γ反应,而不与非相关性蛋白Ag85B、ESAT-6-CFP-10、GM-CSF等发生反应。选取A10细胞株分泌的单克隆抗体、纯化的多克隆抗体及辣根过氧化物酶(HRP)标记的羊抗兔IgG,建立了检测BovIFN-γ的双抗体夹心ELISA方法。实验结果表明,此方法检测敏感性达到2ng/mL,特异性良好,为进一步建立灵敏、特异的病原感染诊断方法奠定了基础。     

非人灵长类结核病的诊断方法及进展

目前非人灵长类结核病的诊断方法单一,给饲养和管理带来影响。通过总结和讨论人的结核病诊断技术,结合非人灵长类的实际情况,指出在结核病检疫中,虽然结核菌素是经典的早期诊断的方法,但血清抗体的检测是结核菌素试验的有效辅助手段,尤其对无反应猴群的结核病检测具有独特的优势。然而,IFNγ的检测有望替代结核菌素试验,实现体外检测结核病。传统的结核菌培养技术时间长,假阴性多,污染率高,给猴的结核病的确诊带来困难。原位PCR技术,能加快诊断速度,提高检出率,特别有利于对小病灶区的病源诊断。虽然目前该技术还不能替代细菌学诊断技术,但两种方法的有效结合将有利于提高非人灵长类的结核病的病源诊断。     

三种结核分枝杆菌检测方法的比较

目的:比较三种结核分枝杆菌检测方法的阳性检出率,并且评价其检测成本等因素,为基层医院快速、准确诊断结核病提供科学依据。方法:对学院附属医院2010---2012年确诊为肺结核病的98例患者标本用抗酸染色涂片法、血清学胶体金法以及聚合酶联链式反应(PCR)分别进行检测。结果:三种检测方法的阳性率分别为:17.3%,76.5%和79.5%。结论:综合三种方法的优缺点,建议基层医院联合使用抗酸涂片染色法和血清学胶体金法进行结核分枝杆菌的检测。     

牛结核病对人类健康的影响及其诊断方法

牛结核病是一种非常重要的人畜共患病,其流行不但对畜牧业的发展产生直接影响,而且会通过各种途径感染人类,给公共卫生带来严重威胁。本文主要就牛结核病的发现、与人结核病之间的关系、对人类健康的影响及其目前的诊断方法等进行介绍。     

肺外结核病微生物学诊断方法的研究和应用进展

肺外结核病指由结核分枝杆菌（Mycobacterium tuberculosis, MTB）感染所引起的发生在肺部以外器官和部位的结核病。近年来肺外结核的发病率逐渐升高,未能得到早期有效治疗的肺外结核病患者可能并发畸形、截瘫甚至死亡等严重后果。微生物学检测方法对从病原学角度诊断肺外结核病至关重要。基于此,总结了近年来肺外结核病细菌学检查方法、结核分枝杆菌的抗原检测与分子生物学检测等微生物学诊断方法的概况及应用进展,并对这些检测方法的优缺点及适用范围进行了分析、比较,以期为今后肺外结核病病原学诊断的研究提供相关信息。     

结核病诊断技术新进展

结核病疫情亟需快速、有效的诊断方法,但长久以来其诊断一直依靠传统的结核分枝杆菌抗酸染色涂片和培养技术,并不能满足快速诊断的需要。为解决这个全球性的问题,近年来出现了多种结核病新的诊断技术和方法,如新的影像学检查及计算机辅助技术、显微镜学诊断技术、结核分枝杆菌快速培养技术、免疫学诊断技术,以及结核分枝杆菌特异性核酸扩增技术。本文主要介绍几种最有代表性的技术和方法,其中部分技术已获得世界卫生组织(World Health Organization,WHO)的推荐,部分正在进行大规模临床研究或验证,反映了近年来结核病诊断发展的新方向。     

干扰素-γ对小鼠哮喘模型治疗的研究

目的:探讨IFN-γ对哮喘小鼠肺部过敏炎症的抑制作用.方法:30只6-8周龄清洁级BALB/c小鼠随机分成正常组、哮喘组和IFN-γ组,以卵白蛋白致敏激发制作小鼠哮喘模型.哮喘组每次激发前给生理盐水鼻内滴入,IFN-γ组每次激发前给IFN-γ鼻内滴入.以ELISA试剂盒测定血清IgE的水平,采血后取肺组织,作病理切片.结果:哮喘组小鼠病理改变与其它各组有明显区别,而IFN-γ组与正常组无明显区别.哮喘组血清IgE水平高于正常组、IFN-γ组,差异均有统计学意义(P＜0.05),但IFN-γ组与正常组比较差异无统计学意义(P＞0.05).结论:IFN-γ局部滴入治疗可抑制小鼠肺部过敏性炎症反应,改善过敏性哮喘的症状,减少EOS在炎症处聚集,降低哮喘小鼠血清IgE水平,在哮喘治疗上有一定的前景.     

转录因子T-bet与Th1/Th2及哮喘的关系

T-bet特异表达于胸腺细胞和Th1细胞,参与调控机体的免疫应答。随着众多学者对该转录因子研究的深入,发现T-bet的表达与Th1/Th2比例失衡有着密切的关系。而Th1/Th2正是目前哮喘发病机制的研究热点。就转录因子T-bet与Th1/Th2及哮喘的关系作一综述。     

干扰素(Ⅰ型α、β,Ⅱ型γ)的分子结构和生物活性的对应关系及其临床应用

干扰素是由干扰素诱生剂诱导生物细胞后所产生的一类高活性多功能的糖蛋白,自发现后一直处于细胞因子基础和临床研究的前沿。本文通过分析Ⅰ型干扰素α、β和Ⅱ型干扰素γ各自的分子结构,来综述对应的亚型的干扰素的生物活性和特点,同时对其临床应用尤其是最近开发的新的适应症进行了介绍和展望。     

Paratuberculosis Vaccination Causes Only Limited Cross-Reactivity in the Skin Test for Diagnosis of Bovine Tuberculosis

Although there is a wide consensus on the efficacy of paratuberculosis vaccination to limit economic losses, its use has been restricted because of its interference in the diagnosis of tuberculosis. Data from a vaccine clinical trial in the Basque Country (Spain) has been evaluated in relationship with bovine tuberculosis intradermal test results. The trial included two herds applying a Test and Culling strategy and five applying an inactivated vaccine. The vaccine was applied to animals of all ages present in each vaccinated herd when joining the trial, and then to all the replacers within their first three months of life. Yearly testing done with the comparative intradermal test (CIT) was applied to all animals older than 6 weeks. Between 2005 and 2011, the study generated 2,033 records from Vaccinated Herds (VH) and 2,252 from Test and Cull herds (TC). Pre-vaccination positive results rate was 2.40% among the 7 herds in the single bovine intradermal tuberculin test (BSIT). Two years later it rose to 20.42% in the VH and remained below at 0.75% in the TC. Applying the CIT reduced these rates to only 0.58% in the VH and to 0.25% in the TC ons. Regarding time since each animal joined the program, the proportion of positives to BSIT was variable and, in some cases, significantly different between time points. With regard to the age of vaccination, no significant differences were found between vaccination within the first year of life and afterwards. Vaccinated animals showed seventeen times more reactions than the non-vaccinated in the BSIT, but only four times more in the CIT. In conclusion, comparative intradermal test can be a useful tool to differentiate paratuberculosis vaccine cross-reactions from specific bovine tuberculosis reactions according to the European and Spanish legislation.     

Bayesian Receiver Operating Characteristic Estimation of Multiple Tests for Diagnosis of Bovine Tuberculosis in Chadian Cattle

Background

Bovine tuberculosis (BTB) today primarily affects developing countries. In Africa, the disease is present essentially on the whole continent; however, little accurate information on its distribution and prevalence is available. Also, attempts to evaluate diagnostic tests for BTB in naturally infected cattle are scarce and mostly complicated by the absence of knowledge of the true disease status of the tested animals. However, diagnostic test evaluation in a given setting is a prerequisite for the implementation of local surveillance schemes and control measures.

Methodology/Principal Findings

We subjected a slaughterhouse population of 954 Chadian cattle to single intra-dermal comparative cervical tuberculin (SICCT) testing and two recently developed fluorescence polarization assays (FPA). Using a Bayesian modeling approach we computed the receiver operating characteristic (ROC) curve of each diagnostic test, the true disease prevalence in the sampled population and the disease status of all sampled animals in the absence of knowledge of the true disease status of the sampled animals. In our Chadian setting, SICCT performed better if the cut-off for positive test interpretation was lowered from >4 mm (OIE standard cut-off) to >2 mm. Using this cut-off, SICCT showed a sensitivity and specificity of 66% and 89%, respectively. Both FPA tests showed sensitivities below 50% but specificities above 90%. The true disease prevalence was estimated at 8%. Altogether, 11% of the sampled animals showed gross visible tuberculous lesions. However, modeling of the BTB disease status of the sampled animals indicated that 72% of the suspected tuberculosis lesions detected during standard meat inspections were due to other pathogens than Mycobacterium bovis.

Conclusions/Significance

Our results have important implications for BTB diagnosis in a high incidence sub-Saharan African setting and demonstrate the practicability of our Bayesian approach for diagnostic test evaluation.     

CFP-10/ESAT-6特异性IFN-g释放反应诊断活动性肺结核的研究

前期研究已经建立了基于结核分枝杆菌特异性抗原CFP-10/ESAT-6融合蛋白刺激外周血单核细胞IFN-γ释放反应,本研究旨在证实该方法在活动性肺结核及结核菌潜伏感染诊断中的意义。实验对象包括111例当地医院收治的活动性肺结核病人(病例组)及283例某大学入学新生(健康对照者)。采集肝素抗凝血,分别加入含结核菌抗原CFP-10/ESAT-6、植物血凝素及无刺激物(PBS)的细胞培养孔中,培养过夜,次日收集血清,进行IFN-γ检测。同时,对其中58位病人志愿者及46位健康对照志愿者进行了结核菌素(PPD)皮内变态反应。病例组与健康对照组的PPD皮内变态反应阳性率分别为79.3%(46/58)和76.1%(35/46),无显著差异(P>0.05),表明PPD皮内变态反应不能用于活动性肺结核的检测。病例组IFN-γ体外释放反应的阳性率为95.5%(106/111),而健康对照组阳性率为16.3%(46/283),两组间均存在极显著差异,表明IFN-γ体外释放反应诊断活动性肺结核具有很高的灵敏度(95.5%)与良好的特异性。在健康组中,IFN-γ体外释放反应与PPD皮内变态反应的总符合率为50.0%,且IFN-g体外...