Ⅲ型登革病毒在THP-1细胞上的ADE模型建立

登革热(dengue fever,DF)是由Ⅰ、Ⅱ、Ⅲ和Ⅳ型登革病毒(dengue virus,DENV)引起的急性传染病,抗体依赖增强感染(antibody-dependent enhancement,ADE)是自限性的登革热以及危及生命的登革出血热(dengue hemorrhagic fever,DHF)或登革休克综合症(dengue shock syndrome,DSS)等重症的主要原因。采用不同稀释度的Ⅱ型登革病毒prM前膜抗体与分离自云南西双版纳重症病人的Ⅲ型登革病毒复合感染THP-1细胞,通过实时荧光定量PCR发现亚中和浓度prM前膜抗体诱发THP-1细胞液中更高浓度的病毒载量。在THP-1细胞系上的研究可为后续研究登革病毒ADE打下坚实的基础。     

登革病毒诱导人单核细胞VEGF的表达及机制

研究登革病毒(Dengue virus,DENV)感染对人单核细胞中血管内皮细胞生长因子(Vascular endothelialgrowth factor,VEGF)表达的影响,并检测分析可影响VEGF表达的天然免疫信号通路。通过Real-time PCR检测,发现不同型DENV(DENV1、DENV2、DENV3)感染THP-1细胞均可诱导VEGF mRNA表达水平呈时间依赖性增加;而DENV2感染也可上调VEGF在原代单核细胞中的表达。通过RNAi技术沉默Toll样受体3(TLR3)及接头蛋白IPS-1,发现DENV感染诱导的VEGF表达明显下调;而ERK、JNK及NF-κB等信号通路的抑制也可下调VEGF的表达水平。本研究证明,DENV感染可诱导人单核细胞中的VEGF高表达,而VEGF高表达依赖于TLR3及IPS-1信号通路的激活,提示VEGF可能是治疗登革出血热的一个靶点。     

登革病毒血清型特异单克隆抗体的制备和鉴定

登革病毒 (Dengue virus,DENV) 是全球传播最为广泛的虫媒病毒,由于缺乏快速鉴别感染病毒血清型的诊断技术,导致异型交叉感染引起重症登革出血热病例居高不下。为实现免疫学方法快速鉴别诊断不同血清型DENV感染,本研究采用哺乳动物细胞293T表达并纯化了4种DENV血清型NS1蛋白,免疫小鼠后通过杂交瘤技术制备了针对NS1蛋白的单克隆抗体。利用酶联免疫吸附方法 (Enzyme-linked immunosorbent assay,ELISA)、间接免疫荧光法 (Indirect immunofluorescence assay,IFA)、免疫斑点杂交试验 (Dot blotting) 以及蛋白质免疫印迹试验 (Western blotting) 确认所制备的单克隆抗体能够有效识别天然病毒NS1以及重组NS1蛋白。获得的单克隆抗体包含2株可识别1–4型DENV NS1蛋白的通用型抗体及3株分别针对DENV-1、DENV-2和DENV-4的血清型特异抗体。以所制备的DENV NS1抗体为基础,采用双抗体夹心ELISA可快速鉴别不同血清型DENV。DENV血清型特异单克隆抗体的制备和甄别DENV血清型ELISA方法的建立为快速鉴别感染DENV血清型的临床诊断奠定了基础。     

Detection of infectious dengue virus by selective real-time quantitative polymerase chain reaction

Dear Editor,The dengue virus(DENV)is a single-stranded positivesense RNA virus that belongs to the family Flaviviridae(Gubler,2002),and has four serotypes,DENV1–DENV4,which are transmitted via Aedes aegypti and Aedes albopictus(Rodriguez-Roche and Gould,2013).It has been reported that more than 50 million dengue infections occur each year(Guzman et al.,2010),and a serious outbreak occurred in the Southern Provinces of     

新型登革疫苗研究进展

登革病毒(Dengue virus,DENV)以伊蚊为主要传播媒介,可感染人,引起登革热(Dengue fever,DF)、登革出血热(Dengue hemorrhagic fever,DHF)及登革休克综合征(Dengue shock syndrome,DSS),其中以登革热最常见,广泛流行于热带和亚     

47kD尾连蛋白在病毒感染过程中的作用

47kD尾连蛋白(tail interacting protein of 47kD, TIP47)是PAT蛋白家族成员,主要定位于脂滴(lipid droplets, LDs)表面及细胞质中,参与脂质代谢调节及病毒复制、转运、组装、释放过程,而且人类免疫缺陷病毒(human immunodeficiency virus, HIV)、丙型肝炎病毒(hepatitis C virus, HCV)和登革病毒(dengue virus, DENV)等多种病毒感染与此过程密切相关。现就目前TIP47在HIV、HCV、DENV等多种病毒感染中所起的作用作一概述,旨在为抗病毒治疗及疫苗研制提供新的思路与途径。     

新型登革疫苗研究进展

登革病毒(Dengue virus,DENV)以伊蚊为主要传播媒介,可感染人,引起登革热(Dengue fever,DF)、登革出血热(Dengue hemorrhagic fever,DHF)及登革休克综合征(Dengue shock syndrome,DSS),其中以登革热最常见,广泛流行于热带和亚     

登革病毒受体的研究进展

登革病毒(Dengue virus,DENV)是登革热(DF)、登革出血热和登革休克综合征(DHF/DSS)的病原体.根据包膜蛋白的抗原性的不同,DENV可分为4个血清型,即DENV1～4.由于血清型比较复杂,目前关于病毒受体仍未得出明确一致的结论.但近几年取得了一些引人注目的进展,比如研究发现甘露糖受体(MR)、CLEC5A等作为DENV的受体,可能在病毒进入宿主细胞过程中发挥重要作用.为此,就近几年关于DENV受体以及病毒进入细胞的机制作一综述.     

Molecular epidemiology demonstrates that imported and local strains circulated during the 2014 dengue outbreak in Guangzhou,China

The dengue virus(DENV) is a vital global public health issue. The 2014 dengue epidemic in Guangzhou, China, caused approximately 40,000 cases of infection and five deaths. We carried out a comprehensive investigation aimed at identifying the transmission sources in this dengue epidemic. To analyze the phylogenetics of the 2014 dengue strains, the envelope(E) gene sequences from 17 viral strains isolated from 168 dengue patient serum samples were sequenced and a phylogenetic tree was reconstructed. All 17 strains were serotype Ⅰ strains, including 8genotype Ⅰ and 9 genotype V strains. Additionally, 6 genotype Ⅰ strains that were probably introduced to China from Thailand before 2009 were widely transmitted in the 2013 and 2014 epidemics, and they continued to circulate until 2015, with one affinis strain being found in Singapore. The other 2 genotype Ⅰ strains were introduced from the Malaya Peninsula in 2014. The transmission source of the 9 genotype Ⅴ strains was from Malaysia in 2014. DENVs of different serotypes and genotypes co-circulated in the 2014 dengue outbreak in Guangzhou. Moreover, not only had DENV been imported to Guangzhou, but it had also been gradually exported, as the viruses exhibited an enzootic transmission cycle in Guangzhou.     

登革病毒共有序列候选DNA疫苗的免疫原性和保护性研究

目的研究登革病毒(Dengue virus, DENV)共有序列候选DNA疫苗pVAX1-cE80在小鼠体内的免疫原性及其保护作用。方法首先利用pVAX1-cE80 DNA免疫BALB/c小鼠,通过ELISA和噬斑减少中和试验(plaque reduction neutralization test, PRNT)分别检测免疫后小鼠血清中抗登革病毒的4种血清型(dengue virus serotype 1-4, DENV1-4)IgG抗体和中和抗体(neutralizing antibody, nAb)效价;利用酶联免疫斑点试验(enzyme-linked immunospot assay, ELISPOT)检测小鼠脾细胞分泌DENV1-4特异性Th1/Th2型细胞因子的能力;通过攻毒试验评价疫苗对DENV1-4感染的保护作用。结果接种疫苗的小鼠可产生针对DENV1-4的四价抗体,其中抗DENV2抗体水平最高,IgG抗体和nAb效价分别为1∶1 086和1∶120;免疫后小鼠脾细胞在DENV1-4抗原刺激下均可分泌较高水平的IFN-γ和IL-4;疫苗免疫可为小鼠提供针对DENV1-4的部分保护作用。结论单一共有序列登革病毒候选DNA疫苗可诱导小鼠产生四价体液免疫反应和细胞免疫反应,并为小鼠提供部分保护作用,为登革病毒共有序列疫苗的研发奠定了基础。     

音乐治疗效应的动物实验研究

近年来国内外关于音乐治疗效应的动物实验研究认为：音乐能影响动物的情绪;音乐还对动物的免疫功能、学习及记忆能力、以及动物的神经系统结构和功能等均有一定影响。该领域的研究有利于深入探索音乐疗法的作用机理。     

热带气旋对红树林的影响研究进展——基于文献计量分析

红树林在防风消浪、促淤保滩、固岸护堤等方面发挥重要的作用,是抵御台风、风暴潮、海岸侵蚀等自然灾害的重要天然屏障。热带气旋是红树林面临的最主要自然威胁之一,削弱了红树林对自然灾害的抵御及生物多性维持等功能发挥。然而,尽管热带气旋对红树林的影响日益受到全球的广泛关注,但缺乏对该领域研究进展的系统分析和总结。以Web of science核心集数据库为数据源,利用CiteSpace软件对1995—2021年间热带气旋对红树林影响研究进行文献计量分析和可视化图谱绘制,以厘清该领域研究的现状、趋势和热点,并揭示未来的发展方向。研究表明：（1）该领域研究年发文量随时间处于波动上升的趋势,尤其2013年后迅速增加,表明该领域的研究日益受到重视;（2）美国、澳大利亚和印度等国家在该领域的研究走在前列,美国的中介中心性最高,其次是德国,美国广泛地与德国、法国、日本等许多国家有密切合作;（3）美国佛罗里达、加勒比地区、澳大利亚北部和印度南部等是当前研究的热点区域;（4）研究热点随时间推移而不断发展,从红树林植被的干扰损害逐渐发展到固碳储碳、海岸防护等功能的影响。全球变化背景下热带气旋对红树林的影响、红树林对热带气旋干扰的弹性、基于遥感和大数据处理的模型模拟等日益受到关注,量化热带气旋对红树林功能的影响、探明热带气旋与海平面上升的关系及对红树林影响、构建完善的观测体系数据集等将是未来研究的重要方向。研究对长期关于热带气旋对红树林影响的研究进展进行定量和可视化分析,可为预测热带气旋对红树林的影响和风险、及减缓和应对其风险等研究提供借鉴参考。     

Time on task effects on safety

Reviewing the literature on time on task effects on safety shows contradictory evidence, especially with regard to 12 h shifts. It is argued that this might depend on methodological problems associated with the analysis of accident data, e.g. selectivity of samples, validity of data bases and study designs, especially for analyses at the company level. Analyses of aggregated data seem to indicate an exponential increase of accident risk with time on task beyond the normal working day. This is supported by some recent studies based on data from the Federal Republic of Germany.     

Perspectives on hair evolution based on some comparative studies on vertebrate cornification

Hair evolution contributed to the biological success of mammals. Hair origin from synapsid scales is speculative and requires extensive modifications of the morphogenetic process transforming lens-shaped dermis of scales into small dermal papillae in hair. Hair evolution from glands is hypothetical but is supported from studies on the signaling control of hair vs. glandular morphogenesis. Based on immunocytochemical and comparative studies, it is hypothesized that the onion-like organization of hair derived from glandular pegs which central part produced lipids and some keratin. In a following stage, involucrin, trichohyalin, and keratins were produced in the central cells of the gland and formed a solid medulla surrounded by keratinocytes of the inner root sheath. The origin of this protohair was possibly related to increased concentration of beta-catenin and other signaling molecules in epithelial cells following the evolution of a dermal papilla. The latter activated the keratogenic genes, already utilized in cells of the claws, in concentric layers of cells of the glandular peg. Lipidogenic genes were depressed. As new genes evolved in the genome of synapsids, new circular layers of keratinocytes containing specialized hard keratins and keratin-associated proteins were formed around medullary cells. The new keratinocytes probably originated the cortex separating medulla from the external cells that became the inner root sheath. The hypothesis indicates that in a following stage, the medulla was obliterated or replaced by cortical cells while the external part of the cortex formed a cuticular surface due to the different growth rate with inner root sheath cells.     

Studies on the Enzymes Acting on Araban

Arabanase was purified by various procedures of gel filtrations and column chromatographies from the submerged culture filtrate of Aspergillus niger grown on the medium containing beet-araban as a carbon source, and the properties of the enzyme was examined. The purified enzyme was homogeneous protein in ultracentrifugal analysis, the optimum pH for enzymatic action was 4.0. The enzyme was thermostable at pH 6.0, namely, even after heating at 98°C for 10 minutes, 20.8 per cent of the initial activity still remained. The enzyme hydrolyzed beet-araban with producing l-arabinose.