北京地区猫疱疹病毒Ⅰ型的分离及鉴定

了解北京地区猫疱疹病毒Ⅰ型(FHV-1)毒株特点,为猫疱疹病毒Ⅰ型的进一步研究及对猫的感染预防控制奠定基础。经特异性PCR检测为FHV-1阳性临床猫眼鼻拭子,经过处理,接种CRFK细胞,通过细胞培养分离病毒。通过间接免疫荧光试验、电镜形态观察、病毒毒力测定及基因序列分析等对分离株进行鉴定。PCR检测FHV-1阳性的14只猫眼鼻拭子接种CRFK细胞,有6只猫样本能使CRFK细胞发生圆缩、拉网集聚等病变;6个样本接种的CRFK病变细胞滴片进行免疫荧光试验,均产生绿色荧光反应;经传代培养,有5株分离株能够稳定传代,其中有2株弱毒,3株强毒;电镜下5株分离株均可见直径100~160nm的球型病毒粒子;5株分离株与FHV-1标准株C-27及2个不同公司来源疫苗株gB、gD基因核苷酸比较同源性均为99%以上。实验室成功分离保存5株能稳定传代的FHV-1毒株,5株分离株与FHV-1标准株及2个疫苗株亲缘关系很近。     

新分离呼吸道肠道病毒生物学特性和S4片段的序列测定

新分离呼吸道肠道病毒(简称呼肠病毒)经过空斑分纯后进行生物学和部分基因序列的鉴定.首先通过BYD株(由端青从北京于某患者标本中分离到的第一株呼肠病毒)对4种传代细胞的敏感性试验,选出L929和LLC-MK2敏感细胞,然后用LLC-MK2细胞进行理化性质试验,血凝试验和形态学鉴定.结果显示该病毒为耐乙醚、不耐酸、不耐热的RNA病毒;对人O型红细胞能产生凝集,滴度达132;电镜下可查见细胞胞浆内有球形、直径为70nm～80nm、双层衣壳的病毒颗粒.提取BYD株RNA并进行S4片段序列分析,结果显示该片段的氨基酸序列与已知呼肠病毒1～3型标准株的同源性分别为95%、90%和95%.以上这些生物学以及S4片断的序列分析结果表明新分离BYD株病毒符合呼肠病毒科的特性.     

新分离呼吸道肠道病毒生物学特性和S4片段的序列测定

新分离呼吸道肠道病毒(简称呼肠病毒)经过空斑分纯后进行生物学和部分基因序列的鉴定。首先通过BYD株(由端青从北京于某患者标本中分离到的第一株呼肠病毒)对4种传代细胞的敏感性试验,选出L929和LLC-MK2敏感细胞,然后用LLC-MK2细胞进行理化性质试验,血凝试验和形态学鉴定。结果显示该病毒为耐乙醚、不耐酸、不耐热的RNA病毒;对人O型红细胞能产生凝集,滴度达1:32;电镜下可查见细胞胞浆内有球形、直径为70nm～80nm、双层衣壳的病毒颗粒。提取BYD株RNA并进行S4片段序列分析,结果显示该片段的氨基酸序列与已知呼肠病毒1～3型标准株的同源性分别为95%、90%和95%。以上这些生物学以及S4片断的序列分析结果表明:新分离BYD株病毒符合呼肠病毒科的特性。     

实验感染的三带喙库蚊和来亨鸡体内西尼罗病毒的分离与鉴定

采用C6/36细胞培养分离活病毒、间接免疫荧光染色检测病毒抗原、RT-PCR扩增病毒基因片段和PCR产物测序等方法,对实验感染的三带喙库蚊Culex tritaeniorhynchus和来亨鸡血液样本中的西尼罗病毒进行分离和鉴定。结果表明,接种实验感染蚊虫研磨液和来亨鸡血液样本的C6/36细胞出现细胞融合、空泡形成的病变效应; 用西尼罗病毒抗血清进行间接免疫荧光染色,感染病毒的细胞呈现黄绿色荧光,为阳性反应; 采用3对不同引物的RT- PCR体系扩增分别出现预期的408 bp、498 bp和559 bp的基因片段,序列测定证实扩增序列与实验所用毒株相应的基因序列基本相同。从而证实实验感染三带喙库蚊和来亨鸡体血液内的西尼罗病毒与实验感染所用的西尼罗病毒Chin-01株一致。     

长爪沙鼠腹腔巨噬细胞对流行性出血热病毒的敏感性

本文就长爪沙鼠腹腔巨噬细胞(MΦ)对流行性出血热病毒(EHFV)的敏感性进行了试验,用3株野鼠型(A9、R3、76-118)和1株家鼠型EHFV(R22),并用对EHFV敏感的Vero-E6细胞作对照,结果沙鼠腹腔巨噬细胞感染EHFV后,第1代第8天前即可查见明显的特异性荧光,第16天左右达高峰,病毒滴度≥10~(-7.5),与Vero-E6细胞比较,培养上清液的病毒滴度,沙鼠MΦ较Vero-E6细胞高1～4个对数,当感染病毒量很低时,在Vero-E6细胞内测不出特异性抗原,而在沙鼠MΦ内病毒仍可繁殖,滴度达10~(-5.(?)),中和试验、间接免疫荧光检测和荧光阻断试验均证明,沙鼠MΦ内繁殖的病毒确实为EHFV。     

猪流行性腹泻病毒地方株LJB/03分离及培养特性

从黑龙江省某猪场疑为病毒性腹泻的发病猪采集腹泻粪便样品,以RT-PCR法扩增出猪流行性腹泻病毒M基因后,采用细胞培养法进行病毒分离。对细胞培养分离物进行间接免疫荧光、免疫电镜观察、RT-PCR及ELISA法检验,其中间接免疫荧光试验可见培养细胞中存在明显的特异性绿色荧光;免疫电镜下可见大小符合预期、有囊膜、花瓣状的典型冠状病毒结构特征;RT-PCR检测证实存在PEDVM基因;间接ELISA检测中平均P/N比值为7.6;从而确认为分离到一株猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV),命名为PEDVLJB/03株。随后,对该分离毒株的培养特性及如何提高病毒滴度进行探索。通过摸索该分离毒株的蚀斑形成条件,建立了PEDV蚀斑形成方法,并采用该方法进行病毒的蚀斑纯化,纯化得到PEDV大蚀斑克隆株和小蚀斑克隆株。对大、小两种蚀斑克隆株的病毒滴度测定结果表明,大小蚀斑克隆株细胞感染滴度相差明显。     

实时荧光PCR技术诊断人偏肺病毒检测效果分析

目的：比较实时荧光PCR检测技术与直接免疫荧光检测技术及间接免疫荧光检测技术在呼吸道人偏肺病毒（hMPV）的检测效果,探讨实时荧光PCR检测技术的应用前景。方法：选取2010年4月至2013年1月因呼吸道感染在我院儿科门诊和住院部接受治疗的患儿鼻咽分泌物标本,共831份（男523例,女308例）。标本按年龄分0~6月龄（68例）、6月~1周岁（153例）、1~3周岁（281例）、3~6周岁（198例）、〉6周岁（131例）五组。采用实时荧光PCR检测技术与直接免疫荧光检测技术及间接免疫荧光检测技术进行检测与分析。结果：采用实时荧光PCR法共检测出221例hMPV阳性（26.6%）,直接免疫荧光法检出121例hMPV阳性（14.6%）,二者相比有统计学意义（X2=5.19,P〈0.05）;间接免疫荧光法检测出103例HMPV阳性（12.4%）与实时荧光PCR法相比有统计学差异（X2=7.17,P〈0.05）;1~3周岁组hMPV感染率与其它组相比差异有统计学意义（X2=12.89,P=0.01）。结论：实时免疫荧光技术hMPV的检测率明显高于直接免疫荧光法和间接免疫荧光法,对hMPV具有很高的临床诊断价值。     

甲肝病毒在猴胚肾细胞和Vero细胞上的分离与适应

使用恒河猴胚肾 (MEK)细胞从临床标本中分离和适应了甲肝病毒W和X ,通过阻断实验、中和实验、免疫荧光和免疫电镜实验、RT PCR对其进行特异性鉴定 ,证明是甲肝病毒。W株和X株第 7代在MEK细胞上的抗原滴度分别为 1∶5 12、1∶10 2 4,感染滴度 (logTCID50 /mL)分别为 8.17、8.5 0。只有分离株W可以适应于Vero细胞 ,第 6代 2 1d抗原滴度为 1∶2 5 6 ,感染滴度 (logTCID50 /mL)为 8.0 0。     

流行性出血热病毒在MA-104和Vero-E6传代细胞上繁殖动态的比较

用流行性出血热病毒(陈株)分別感染MA-104和Vero-E6传代细胞,结果受病毒感染的MA-104细胞荧光阴性细胞出现早,感染滴度高,胞浆内颗粒大,提示MA-104细胞用于该病毒的分离传代及抗原片的制作等方面优于Vero-E6细胞。流行性出血热病毒(EHFV)在某些原代及传代细胞上能适应增殖,国内外已有过报导。但用对轮状病毒十分敏感的恒河猴胚肾MA-104细胞培养和增殖EHFV并与通常使用分离该病毒的VeroE6细胞进行繁殖动态观察,尚未有过报导。本文用间接免疫荧光法(IFA)比较观察EHFV在两种细胞上的增殖动态,为MA-104细胞代替常规Vero-E6细胞用于该病毒的分离、传代等研究以及抗原片的制备提供依据。     

Comparison of Odontogenic Differentiation of Human Dental Follicle Cells and Human Dental Papilla Cells

Classical tooth development theory suggests that dental papilla cells (DPCs) are the precursor cells of odontoblasts, which are responsible for dentin development. However, our previous studies have indicated that dental follicle cells (DFCs) can differentiate into odontoblasts. To further our understanding of tooth development, and the differences in dentinogenesis between DFCs and DPCs, the odontogenic differentiation of DFCs and DPCs was characterized in vitro and in vivo. DFCs and DPCs were individually combined with treated dentin matrix (TDM) before they were subcutaneously implanted into the dorsum of mice for 8 weeks. Results showed that 12 proteins were significantly differential, and phosphoserine aminotransferase 1 (PSAT1), Isoform 2 of hypoxia-inducible factor 1-alpha (HIF1A) and Isoform 1 of annexin A2 (ANXA2), were the most significantly differential proteins. These proteins are related to regulation of bone balance, angiogenesis and cell survival in an anoxic environment. Both DFCs and DPCs express odontogenic, neurogenic and peridontogenic markers. Histological examination of the harvested grafts showed that both DFCs and DPCs form pulp-dentin/cementum-periodentium-like tissues in vivo. Hence, DFCs and DPCs have similar odontogenic differentiation potential in the presence of TDM. However, differences in glucose and amino acid metabolism signal transduction and protein synthesis were observed for the two cell types. This study expands our understanding on tooth development, and provides direct evidence for the use of alternative cell sources in tooth regeneration.     

基于人多潜能干细胞的人类疾病研究与治疗

人多潜能干细胞(hPSC)包括人胚胎干细胞(hESC)和诱导性多潜能干细胞(hiPSC),理论上具有分化成为人类所有细胞类型的能力.基于hPSC的基因打靶技术,不但可以纠正人基因组中的遗传突变用于细胞治疗,还可以通过反向遗传学的方式向hPSC引入疾病特异的突变.将携带人类疾病遗传基因的hPSC分化为特定的细胞类型,在理论上可以在体外模拟人类疾病的发生,研究人类疾病发生的机理,并建立体外筛选平台寻找治疗性药物.基因编辑和干细胞技术的结合将为人类疾病的机制研究和再生医学治疗带来革命性的突破.     

人鼻病毒1B感染人扁桃体上皮细胞和人肺支气管上皮细胞的比较代谢组学研究

人鼻病毒(Human rhinovirus,HRV)是呼吸道感染的主要病原体之一,明确HRV的致病机制能为有效防控该病毒感染提供科学依据.为确定1B型HRV(human rhinovirus type 1B,HRV1B)感染致宿主细胞的代谢组改变及差异性,本文采用非靶向代谢组学技术研究HRV1B感染人扁桃体上皮细胞UT-SCC-60B和人肺支气管上皮细胞BEAS-2B后代谢组的改变情况.HRV1B感染UT-SCC-60B细胞6h和12h分别有21个差异显著代谢产物(differentially significant metabolites,DSMs)(上调13个、下调8个)和51个DSMs(上调42个、下调9个),HRV1B感染UT-SCC-60B和BEAS-2B细胞6h和12h后,比较分析发现分别有303个DSMs(上调69个,下调234个)和324个DSMs(上调88个,下调236个),未知DSMs占据比例较大.脂肪酸、脂质、氨基酸、核苷酸和糖类的比例随着感染时间的延长而增加,7-酮基脱氧胆酸、溶血磷脂酰胆碱、垂盆草甙、组氨酸-甘氨酸、腺苷酸等涉及到胆汁酸代谢、脂肪酸和脂质代谢、糖代谢、氨基酸代谢和核苷酸代谢.因此,细胞水平表明HRV1B感染改变了人上皮细胞的脂肪酸、脂质、氨基酸、核苷酸和糖类的代谢水平.     

Efficient Generation Human Induced Pluripotent Stem Cells from Human Somatic Cells with Sendai-virus

A few years ago, the establishment of human induced pluripotent stem cells (iPSCs) ushered in a new era in biomedicine. Potential uses of human iPSCs include modeling pathogenesis of human genetic diseases, autologous cell therapy after gene correction, and personalized drug screening by providing a source of patient-specific and symptom relevant cells. However, there are several hurdles to overcome, such as eliminating the remaining reprogramming factor transgene expression after human iPSCs production. More importantly, residual transgene expression in undifferentiated human iPSCs could hamper proper differentiations and misguide the interpretation of disease-relevant in vitro phenotypes. With this reason, integration-free and/or transgene-free human iPSCs have been developed using several methods, such as adenovirus, the piggyBac system, minicircle vector, episomal vectors, direct protein delivery and synthesized mRNA. However, efficiency of reprogramming using integration-free methods is quite low in most cases.Here, we present a method to isolate human iPSCs by using Sendai-virus (RNA virus) based reprogramming system. This reprogramming method shows consistent results and high efficiency in cost-effective manner.     

人尿源性干细胞及人脐带间充质干细胞的生物学性状比较

该研究探讨人尿源性干细胞(human urine-derived stem cells,hUSCs)及人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,hUC-MSCs)的生物学性状差异。分离培养hUSCs及hUC-MSCs,显微镜下观察细胞形态,流式细胞术检测干细胞表面标记物,锥虫蓝拒染实验及克隆形成实验检测细胞增殖能力,划痕实验及Transwell迁移实验检测细胞迁移能力,碱性磷酸酶(alkaline phosphatase,ALP)染色、茜素红染色、油红O染色及阿利新蓝染色评估多向分化潜能。hUSCs为米粒状贴壁生长细胞,hUC-MSCs为长梭形贴壁细胞,呈旋涡状排列生长,两种细胞表型分析相似,均表达多种间充质干细胞标志物,但CD24在hUC-MSCs表达阳性,而CD105在hUSCs表达阳性。hUC-MSCs的增殖及迁移能力优于hUSCs,但后者的克隆形成能力更强。hUSCs及hUCMSCs都具有成骨、成脂、成软骨分化能力,hUC-MSCs的成骨能力强而hUSCs的成脂能力强。该研究成功分离培养出增殖能力强并具有多向分化潜能的hUSCs,该细胞与hUC-MSCs相比具有相似的生物学性状,可作为再生医学自体移植的理想种子细胞来源。     

Isolation of Myeloid Dendritic Cells and Epithelial Cells from Human Thymus

In this protocol we provide a method to isolate dendritic cells (DC) and epithelial cells (TEC) from the human thymus. DC and TEC are the major antigen presenting cell (APC) types found in a normal thymus and it is well established that they play distinct roles during thymic selection. These cells are localized in distinct microenvironments in the thymus and each APC type makes up only a minor population of cells. To further understand the biology of these cell types, characterization of these cell populations is highly desirable but due to their low frequency, isolation of any of these cell types requires an efficient and reproducible procedure. This protocol details a method to obtain cells suitable for characterization of diverse cellular properties. Thymic tissue is mechanically disrupted and after different steps of enzymatic digestion, the resulting cell suspension is enriched using a Percoll density centrifugation step. For isolation of myeloid DC (CD11c⁺), cells from the low-density fraction (LDF) are immunoselected by magnetic cell sorting. Enrichment of TEC populations (mTEC, cTEC) is achieved by depletion of hematopoietic (CD45^hi) cells from the low-density Percoll cell fraction allowing their subsequent isolation via fluorescence activated cell sorting (FACS) using specific cell markers. The isolated cells can be used for different downstream applications.     

Durotaxis by Human Cancer Cells

Durotaxis is a type of directed cell migration in which cells respond to a gradient of extracellular stiffness. Using automated tracking of positional data for large sample sizes of single migrating cells, we investigated 1) whether cancer cells can undergo durotaxis; 2) whether cell durotactic efficiency varies depending on the regional compliance of stiffness gradients; 3) whether a specific cell migration parameter such as speed or time of migration correlates with durotaxis; and 4) whether Arp2/3, previously implicated in leading edge dynamics and migration, contributes to cancer cell durotaxis. Although durotaxis has been characterized primarily in nonmalignant mesenchymal cells, little is known about its role in cancer cell migration. Diffusible factors are known to affect cancer cell migration and metastasis. However, because many tumor microenvironments gradually stiffen, we hypothesized that durotaxis might also govern migration of cancer cells. We evaluated the durotactic potential of multiple cancer cell lines by employing substrate stiffness gradients mirroring the physiological stiffness encountered by cells in a variety of tissues. Automated cell tracking permitted rapid acquisition of positional data and robust statistical analyses for migrating cells. These durotaxis assays demonstrated that all cancer cell lines tested (two glioblastoma, metastatic breast cancer, and fibrosarcoma) migrated directionally in response to changes in extracellular stiffness. Unexpectedly, all cancer cell lines tested, as well as noninvasive human fibroblasts, displayed the strongest durotactic migratory response when migrating on the softest regions of stiffness gradients (2–7 kPa), with decreased responsiveness on stiff regions of gradients. Focusing on glioblastoma cells, durotactic forward migration index and displacement rates were relatively stable over time. Correlation analyses showed the expected correlation with displacement along the gradient but much less with persistence and none with cell speed. Finally, we found that inhibition of Arp2/3, an actin-nucleating protein necessary for lamellipodial protrusion, impaired durotactic migration.     

Freezing and Thawing Human Embryonic Stem Cells

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells from a frozen stock have become important procedures performed in routine hES cell culture. Since hES cells are very sensitive to the stresses of freezing and thawing, special care must taken. Here we demonstrate the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage.Download video file.^{(102M, mp4)}