内参基因β-actin质粒标准品的构建

为构建检测内参基因β-actin mRNA表达水平差异的标准品，以成人外周血细胞的总RNA为模板、Random 6 mers为引物反转录合成cDNA，用该cDNA为模板PCR扩增人β-actin基因相应的cDNA片段，构建PMD-18-β-actin重组质粒，鉴定测序后，用荧光定量PCR制作标准曲线。结果外周血提取的总RNA完整性良好，构建的β-actin质粒经PCR扩增后得到一186 bp的清晰条带，测序结果与目的片段完全一致，且质粒的原始浓度为2.39×1013 copies/mL，倍比稀释至2.0×104 copies/mL均能得到良好的标准曲线（R2=1），提示构建β-actin基因荧光定量PCR标准质粒成功。     

Taqman探针定量检测ICOS/ICOSL基因表达的方法

背景：近年来可诱导共刺激分子(inducible costimulator, ICOS)/可诱导共刺激分子配体(ICOS Ligand,ICOSL)在抗感染、抗移植反应、抗肿瘤、治疗自身免疫性疾病等多方面领域受到了越来越多的关注。目前对ICOS/ICOSL表达量的研究大多基于分子水平,国内外尚鲜见ICOS/ICOSL mRNA定量检测的报道。 目的：构建ICOS/ICOSL cDNA质粒标准品,建立Taqman探针检测ICOSL/ICOSL基因表达量的方法。 方法：以胃腺癌组织总RNA为模板、Random 9 mers为引物反转录合成cDNA,用该cDNA为模板聚合酶链反应扩增人ICOS/ICOSL基因相应的cDNA目的片段,构建PMD-18-ICOS/ICOSL重组质粒,鉴定测序后,用Taqman探针实时荧光定量聚合酶链反应制作标准曲线。 结果与结论：组织提取的总RNA完整性良好,构建的ICOS/ICOSL质粒测序结果与目的片段一致,质粒的原始浓度为6.10×1013,4.31×1013 copies/mL,倍比稀释后用Taqman探针荧光定量聚合酶链反应检测,在1012~1013 copies/mL线性关系良好(R2=1),提示成功建立了Taqman探针定量检测ICOS/ICOSL基因表达的方法。 关键词：共信号分子;可诱导共刺激分子;配体;mRNA;实时定量聚合酶链反应     

外周血淋巴细胞CD40／CD40L表达与多发性肌炎／皮肌炎发病关系

目的:初步探讨协同刺激分子CD40/CD40L在多发性肌炎(PM)/皮肌炎(DM)发病机制中的作用。方法:采用流式细胞学检测PM/DM患者外周血淋巴细胞CD40、CD40L的表达,并与正常健康人对照。结果:CD40、CD40L在正常健康人外周血淋巴细胞几乎无表达,但在PM/DM患者表达增高,PM患者CD40平均荧光强度为10.24±4.15,CD40L平均荧光强度为1.35±0.77;DM患者CD40平均荧光强度为13.67±5.83,CD40L平均荧光强度为1.73±0.98。PM/DM患者比较差异无显著性(P>0.05)。结论:CD40/CD40L的表达可能参与了PM/DM的发病。     

白细胞介素3基因cDNA克隆与转导及其在脐血CD34+细胞中的表达

背景：单份脐血难以满足成人造血干细胞移植的要求,需对其进行体外扩增,这不仅需要较长的时间和较高的培养条件,而且容易导致干细胞自身分化,从而影响移植效果。 目的：克隆人白细胞介素3基因cDNA,构建其真核表达载体并转导脐血CD34+细胞,观察白细胞介素3的表达情况。 设计、时间及地点：细胞-基因组学体外实验,于2008年在承德医学院完成。 材料：健康成人外周血由承德市中心血站提供,脐血由承德市妇幼保健院提供,提供者对实验均知情同意。 方法：采集健康成人外周血,应用Ficoll密度梯度法分离单个核细胞,免疫磁珠法分离脐血CD34+细胞。提取白细胞介素3 mRNA,应用RT-PCT扩增白细胞介素3 cDNA,构建真核表达载体pcDNA3/IL-3。设立2组：实验组利用基因枪技术将pcDNA3/IL-3导入脐血CD34+细胞中,对照组未行转染。 主要观察指标：采用人白细胞介素3 ELISA试剂盒检测脐血CD34+细胞上清液中白细胞介素3水平。 结果：扩增的白细胞介素3基因cDNA理论上应为616 bp,实际PCR产物经琼脂糖凝胶电泳后,紫外线下可见预期大小的条带,反转录合成的cDNA完整。BamHⅠ和XbaⅠ双酶切后,电泳可见616 bp的插入片段,与白细胞介素3基因序列相同。转染第1~7天,实验组脐血CD34+细胞上清液中白细胞介素3水平明显高于未转染对照组(t=3.46,P < 0.05)。 结论：白细胞介素3基因cDNA克隆成功,并成功构建了真核表达质粒pcDNA3/IL-3,pcDNA3/IL-3能在脐血CD34+细胞中短期有效表达。     

叉头转录因子1质粒标准品的构建

背景：研究表明叉头转录因子1是一种新的2型糖尿病易感基因,但2型糖尿病患者与健康人的叉头转录因子1基因在转录水平上差异性的研究不多。由于还没有商品化叉头转录因子1的质粒标准品,因此有必要构建其标准品。 目的：构建应用实时荧光定量-聚合酶链反应检测叉头转录因子1 mRNA的质粒标准品。 设计、时间及地点：单一样本重复实验,于2007-11/2008-03在苏州大学附属第一医院检验科实验室完成。 材料：SYBR ExScript TM反转录-聚合酶链反应Kit试剂盒,SYBR Premix Ex TaqTM试剂盒,凝胶回收纯化DNA试剂盒,质粒DNA小量纯化试剂盒,PMD18-T Vector试剂盒等。 方法：从健康志愿者血标本中提取总RNA,反转录合成cDNA,以cDNA为模板应用聚合酶链反应扩增出目的片段,对其回收纯化连接到PMD18-T载体及转化JM109,阳性克隆经测序分析,确认重组质粒正确。抽提重组质粒,用紫外分光光度仪测定其浓度,再根据公式换算成拷贝浓度,最后稀释成梯度标准品。 主要观察指标：重组质粒聚合酶链反应和基因测序结果,标准品标准曲线的相关系数及标准品的重复性。 结果：成功构建了叉头转录因子1质粒标准品,通过聚合酶链反应及基因测序鉴定其目的片段已成功插入载体。各稀释度的标准品经荧光定量-聚合酶链反应扩增后,其循环阈值与起始模板量的对数值之间有着良好的线性关系,线性范围是2.39×(105~1012) copies/mL。各稀释度标准品的批内重复性好,其变异系数范围为0.29%~1.16%。 结论：实验成功构建了具有较好灵敏度和重复性的叉头转录因子1质粒标准品。     

真菌源性CD::UPRT联合基因治疗脑胶质瘤的实验研究

目的研究5-FC/CD：：UPRT联合基因治疗策略对胶质瘤细胞C6的杀伤效应。方法扩增yCD：：UPRT融合基因并构建含yCD：：UPRT基因的重组表达载体；载体转染包装细胞PT67,所获重组病毒转染胶质瘤细胞C6,筛选并鉴定阳性转基因克隆；用MTT法检测不同浓度5-FC对CD：：UPRT转基因细胞的杀伤效应。结果PCR法扩增出全长CD：：UPRT基因,经测序证实序列正确,重组逆转录病毒表达载体pLXSN-yCD：：UPRT经双酶切获目的条带,载体转染包装细胞获重组逆转录病毒(滴度达3．5×10~6CFU/ml)并转染C6,经筛选获得转基因阳性克隆C6-yCD：：UPRT细胞株,检测显示该细胞株有效表达目的基因。当5-FC终浓度≥10μmol/L时,实验组与对照组的细胞增殖力出现显著差异(P＜0．01),5-FC作用96h后电镜观察到凋亡小体。结论5-FC/yCD：：UPRT联合基因治疗策略对胶质瘤细胞C6有明显的杀伤作用。     

保守性多巴胺能神经营养因子重组杆状病毒转移载体的构建及鉴定

目的 构建并鉴定小鼠保守性多巴胺能神经营养因子(mCDNF)重组杆状病毒转移载体pFastBacHTb-mCDNF. 方法 应用Trizol法提取小鼠组织总RNA,反转成cDNA,经PCR扩增得到带有预定酶切位点(BamH Ⅰ、Xho Ⅰ)的mCDNF基因全长(564 bp),回收片段并克隆至pGEM-T载体,测序验证PCR结果的准确性.将mCDNF定向克隆到pFastBacHTb载体,构建含有mCDNF基因的重组质粒pFastBacHTb-mCDNF,转化大肠杆菌DH5α感受态细胞,氨苄青霉素抗性筛选阳性克隆,摇菌抽取质粒进行测序和双酶切鉴定. 结果 RT-PCR扩增产物经琼脂糖凝胶电泳显示得到预定大小的目的 条带(564 bp),mCDNF的T-A克隆经蓝白斑抗性筛选获得阳性克隆,PCR及测序均提示pGEM-T-CDNF载体成功构建.重组质粒pGEM-T-mCDNF和pFastBacHTb载体进行BamH Ⅰ、Xho Ⅰ限制性内切酶酶切后再连接,得到pFastBacHTb-mCDNF重组质粒,并经PCR、酶切及测序验证无误. 结论 本实验成功构建了mCDNF重组杆状病毒转移载体pFastBacHTb-mCDNF,为该营养因子的进一步研究奠定了一定基础.     

分化型胚胎软骨发育基因1特异性小干扰RNA表达质粒的构建和鉴定

背景：分化型胚胎软骨基因1可调控肿瘤生长、凋亡、衰老相关因子，与肿瘤的发生发展有着重要的联系。 目的：构建针对人分化型胚胎软骨基因1的小干扰RNA表达载体。 方法：从NCBI中查找人分化型胚胎软骨基因1基因全长mRNA序列，利用Katahdin提供的在线小干扰 RNA模板序列设计软件，设计针对分化型胚胎软骨基因1的2条shRNA 的 DNA 模板单链，合成靶向分化型胚胎软骨基因1基因转录可形成茎环结构的寡聚核苷酸，退火后与酶切后的pGreenPuro™ shRNA Cloning and Expression Lentivector质粒连接，在JM-109菌株中扩增，并进行质粒DNA琼脂糖凝胶电泳分析、紫外分光光度计检测、菌落PCR以及测序鉴定。 结果与结论：将含有分化型胚胎软骨基因1目标序列25 bp 的双链 DNA插入片段，连接到pGreenPuro™ shRNA Cloning and Expression Lentivector质粒形成重组质粒。质粒DNA琼脂糖凝胶电泳和紫外分光光度计分析结果确认所提质粒纯度较高，可用于后续实验。菌落PCR结果表明产物大小约为170 bp，与预期相符。测序结果表明pGreenPuro™ shRNA Cloning and Expression Lentivector质粒已经插入人分化型胚胎软骨基因1的干扰合成片段，无碱基突变。成功构建了靶向分化型胚胎软骨基因1-小干扰 RNA表达载体。     

中国东北地区CD40及CD40L基因多态性与散发帕金森病的相关性分析

目的 探究CD40基因rs1883832位点及CD40L基因rs1126535位点单核苷酸多态性与帕金森病(Parkinson disease,PD)的相关性。方法 本研究纳入285名中国东北地区汉族健康人和396例PD患者。根据其发病年龄将PD组患者再分为早发PD组(发病年龄≤50岁)和晚发PD组(发病年龄 50岁),收集一般临床资料,提取外周血基因组DNA,利用MALDI-TOF-PEX技术检测rs1883832位点及rs1126535位点多态性分布情况,分析其与帕金森病的相关性。结果 EOPD组与对照组rs1883832位点基因型分布有统计学差异(P 0. 05),等位基因频率在两组间没有统计学差异。PD组和LOPD组与对照组在rs1883832位点及rs1126535位点上,基因型及等位基因型频率无统计学差异。结论 CD40基因rs1883832位点单核苷酸多态性与中国东北地区汉族早发帕金森病相关,T等位基因可能是EOPD的危险因素。     

靶向人血管紧张素原小干扰RNA表达质粒的构建和鉴定

背景：RNA干扰技术通过将具有一定结构特点、长19~25 bp的双链小干扰RNA导入哺乳动物细胞,特异性降解与其序列具有同源性的mRNA分子,导致目的基因表达抑制。 目的：拟构建针对人血管紧张素原mRNA的小干扰RNA表达载体,从而抑制肾素基因在脂肪细胞的表达。 方法：从NCBI中查找人血管紧张素原基因全长mRNA序列(NM000029),利用GeneScript公司提供的在线小干扰RNA模板序列设计软件,自行设计靶向血管紧张素原的两条shRNA的DNA模板单链,合成靶向血管紧张素原基因转录可形成茎环结构的寡聚核苷酸,退火后与酶切后的psiRNAT-U6.1/Neo质粒连接,在TOP10菌株中扩增,并测序鉴定。 结果与结论：将含有血管紧张素原-mRNA目标序列19 bp的双链DNA插入片段,连接到pRNAT-U6.1/Neo质粒形成重组质粒。EcoRⅠ和Hind Ⅲ双酶切后,空载体得到351 bp小片段,而人重组质粒得到397 bp小片段,与预期相符。EcoRⅠ和Kpn Ⅰ双酶切后,空载体得到1条345 bp小片段,而人重组载体没有得到小片段条带,与预期相符。测序结果表明psiRNAT-U6.1/Neo质粒已经插入人脂肪细胞的干扰合成片段,无碱基突变,成功构建了靶向血管紧张素原-小干扰RNA表达载体。     

The role of CD40 in CD40L- and antibody-mediated platelet activation

Our initial finding that CD40- and CD40 ligand (CD40L)-deficient mice displayed prolonged tail bleeding and platelet function analyzer (PFA-100) closure times prompted us to further investigate the role of the CD40-CD40L dyad in primary hemostasis and platelet function. Recombinant human soluble CD40L (rhsCD40L), chemical cross-linking of which suggested a trimeric structure of the protein in solution, activated platelets in a CD40-dependent manner as evidenced by increased CD62P expression. CD40 monoclonal antibody (mAb) M3, which completely blocked rhsCD40L-induced platelet activation, also prolonged PFA-100 closure times of normal human blood. In contrast, CD40 mAb G28-5 showed less potential in blocking rhsCD40L-induced CD62P expression and did not affect PFA-100 closure times. However, when added to the platelets after rhsCD40L, G28-5 significantly enhanced the platelet response by causing clustering of, and signaling through, FcgammaRII. Similarly, higher order multimeric immune complexes formed at a 1/3 molar ratio of M90, a CD40L mAb, to rhsCD40L induced strong Fcgamma RII-mediated platelet activation when translocated to the platelet surface in a CD40-dependent manner, including the induction of morphological shape changes, fibrinogen binding, platelet aggregation, dense granule release, microparticle generation and monocyte-platelet-conjugate formation. The results suggest that CD40 may play a role in primary hemostasis and platelet biology by two independent mechanisms: First, by functioning as a primary signaling receptor for CD40L and, second, by serving as a docking molecule for CD40L immune complexes. The latter would also provide a potential mechanistic explanation for the unexpected high incidence of CD40L mAb-associated thrombotic events in recent human and animal studies.     

Systemic upregulation of CD40 and CD40 ligand mRNA expression in multiple sclerosis

It is increasingly clear that the CD40 and CD40 ligand (CD40L) receptor-ligand pair mediates a crucial activation signal in both cell-mediated and humoral immune responses. Here, we detected mRNA levels of CD40 and CD40L in non-stimulated peripheral blood mononuclear cells in 46 patients with multiple sclerosis (MS) and 46 healthy controls by a competitive RT - PCR procedure allowing quantification without previous culture or antigenic stimulation. The levels of CD40 and CD40L mRNA were markedly increased in MS patients (P<0.0001) compared with healthy controls. There was no difference between clinical MS subgroups or stage of disease. Our findings indicate that, although MS is an organ specific disorder, an increased signaling via the CD40 and CD40L pathway may be present at the systemic level. The nature of this upregulation, whether primary or secondary to the organ-specific autoimmune response, is yet to be determined. Since interference with CD40/CD40L is an effective way to interfere with autoimmune model diseases such as experimental autoimmune encephalomyelitis, it may be relevant to investigate further the role of these molecules in the pathogenesis of MS.     

Neutrophil CD40 enhances platelet-mediated inflammation

INTRODUCTION: CD40 is a transmembrane protein expressed on monocytes, macrophages, endothelial cells, and platelets. Platelets are the richest source of soluble CD40 ligand (sCD40L) and interact with monocytes and endothelial cells via CD40. While CD40 was recently reported to be present on neutrophils, the detailed mechanism of its interaction with platelets via CD40-CD40L has not been examined. MATERIALS AND METHODS: The existence of neutrophil CD40 was verified by real-time PCR and western blot. Platelet sCD40L release was measured by ELISA. Neutrophil superoxide generation was measured by chemiluminescence and confocal microscopy. The neutrophil-platelet conjugates were measured by flow cytometry. RESULTS AND CONCLUSION: The presence of neutrophils enhances stimulation-induced platelet release of sCD40L. The addition of platelets leads to an enhancement of neutrophil superoxide and reactive oxygen species (ROS) generation. The specificity of the CD40-CD40L pathway in the neutrophil-platelet interaction was confirmed by using recombinant soluble CD40L (rsCD40L) and an anti-CD40L antibody. The involvement of the PI3 kinase/Akt pathway in neutrophil superoxide production was revealed by using LY294002 in isolated neutrophils/platelets experiments, as well as during whole blood aggregation-mediated neutrophil-platelet conjugation. N-acetylcysteine, a scavenger of ROS, eliminates both neutrophil superoxide generation and sCD40L release from activated platelets. These data suggest that activated neutrophils release ROS in a PI3 kinase-dependent manner, contributing to platelet activation and further sCD40L release in a redox-controlled positive feed-back loop. In conclusion, our results define a new pathway by which platelets and neutrophils interact and modulate each other's function, and may be relevant in understanding acute thrombo-inflammatory processes.     

Membrane-associated CD40L and sCD40L in atherothrombotic disease

Recent data suggests that CD40L is involved in the pathogenesis of atherothrombotic disease. This review will focus on the history of CD40L, its role in platelet-mediated pathogenesis of atherothrombotic disease, its association to clinical syndromes and procedures, and its role in determining plaque rupture.     

Induction of beta-chemokine secretion by human brain microvessel endothelial cells via CD40/CD40L interactions

beta-chemokines play an important role during the course of central nervous system (CNS) inflammation. Using primary cultures of human cerebral microvascular endothelial cells, we detected increased monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation normal T cell expressed and secreted (RANTES) production following incubation with soluble CD40L. These results suggest a potential mechanism by which activated CD40L positive T cells may enhance beta-chemokine expression and thus influence the recruitment of mononuclear cells across the human blood-brain barrier.     

Expression of CD40 induces neural apoptosis

The tumor necrosis factor receptor superfamily includes 12 members, some of which (e.g., tumor necrosis factor receptor I and FAS) induce cell death triggered by ligand binding. Another member of the superfamily, the neurotrophin receptor p75^NTR, induces neural apoptosis, with apoptosis being inhibited by binding of ligand to the receptor. As such, it is a candidate for the mediation of neurotrophin dependence. Here, we show that CD40, a superfamily member that is closely related to p75^NTR, also induces neural apoptosis, but apoptosis is inhibited by binding of the G28-5 monoclonal antibody to CD40. These results provide further support for a model in which some members of the tumor necrosis factor receptor superfamily induce apoptosis triggered by ligand binding, whereas other members may, at least under certain conditions, induce apoptosis in the absence of ligand binding, with apoptosis being inhibited by binding of ligand or monoclonal antibody. J. Neurosci. Res. 50:383–390, 1997. © 1997 Wiley-Liss, Inc.     

Death receptor-mediated apoptosis in human malignant glioma cells: modulation by the CD40/CD40L system

CD40, a TNF-R-related cell surface receptor, is shown here to be expressed by glioma cells in vitro and in vivo. Glioma cell lines expressing low levels of CD40 at the cell surface resist cytotoxic effects of CD40L. CD40 gene transfer sensitizes glioma cells to CD40L. Inhibition of protein synthesis potentiates cell death which involves CD40 clustering and caspases 8 and 3 processing. CD40-transfected LN-18 cells acquire resistance to CD95L. In contrast, subtoxic concentrations of CD40L strongly sensitize these cells for TNF-alpha-induced apoptosis. Bispecific CD40xCD95 antibodies specifically kill glioma cells, disclosing the property of endogenous CD40 to facilitate death signalling.