In vivo far-red luminescence imaging of a biomarker based on BRET from Cypridina bioluminescence to an organic dye

We aimed to develop a far-red luminescence imaging technology for visualization of disease specific antigens on cell surfaces in a living body. First, we conjugated a far-red fluorescent indocyanine derivative to biotinylated Cypridina luciferase. This conjugate produced a bimodal spectrum that has long-wavelength bioluminescence emission in the far-red region as a result of bioluminescence resonance energy transfer. To generate a far-red luminescent probe with targeting and imaging capabilities of tumors, we then linked this conjugate to an anti-human Dlk-1 monoclonal antibody via the biotin-avidin interaction. This far-red luminescent probe enabled us to obtain high-resolution microscopic images of live, Dlk-1-expressing Huh-7 cells without an external light source, and to monitor the accumulation of this probe in tumor-bearing mice. Thus this far-red luminescent probe is a convenient analytical tool for the evaluations of monoclonal antibody localization in a living body.     

Novel chimeric thyroid-stimulating hormone-receptor bioassay for thyroid-stimulating immunoglobulins

Thyroid-stimulating immunoglobulins (TSI) are a functional biomarker of Graves' disease (GD). To develop a novel TSI bioassay, a cell line (MC4-CHO-Luc) was bio-engineered to constitutively express a chimeric TSH receptor (TSHR) and constructed with a cyclic adenosine monophosphate (cAMP)-dependent luciferase reporter gene that enables TSI quantification. Data presented as percentage of specimen-to-reference ratio (SRR%) were obtained from 271 patients with various autoimmune and thyroid diseases and 180 controls. Sensitivity of 96% and specificity of 99% for untreated GD were attained by receiver operating characteristic analysis, area under the curve 0·989, 95% confidence interval 0·969-0·999, P = 0·0001. Precision testing of manufactured reagents of high, medium, low and negative SRR% gave a percentage of coefficient-of-variation of 11·5%, 12·8%, 14·5% and 15·7%, respectively. There was no observed interference by haemoglobin, lipids and bilirubin and no non-specific stimulation by various hormones at and above physiological concentrations. TSI levels from GD patients without (SRR% 406 ± 134, mean ± standard deviation) or under anti-thyroid treatment (173 ± 147) were higher (P < 0·0001) compared with TSI levels of patients with Hashimoto's thyroiditis (51 ± 37), autoimmune diseases without GD (24 ± 10), thyroid nodules (30 ± 26) and controls (35 ± 18). The bioassay showed greater sensitivity when compared with anti-TSHR binding assays. In conclusion, the TSI-Mc4 bioassay measures the functional biomarker accurately in GD with a standardized protocol and could improve substantially the diagnosis of autoimmune diseases involving TSHR autoantibodies.     

应用动物活体生物发光技术观察紫杉醇混合胶束的抑瘤效果

活体动物成像技术是近年来发展成熟并得到认可的一种新型影像检测技术,其突出优越性是可以对活体病灶的形态大小进行在体无损伤直观准确检测[1]。活体动物成像技术的基本原理是透过体表,接     

构建p53双荧光报告载体及其功能验证

目的：构建p53双荧光报告载体,验证其能否模拟野生型p53的生物学活性并适用于高通量筛选。方法：用PCR在p53和萤火虫荧光素酶的开放阅读框两端引入酶切位点并移除p53的终止密码和萤火虫荧光素酶的起始密码,然后将二者插入到由内部核糖体进入位点引导的海肾荧光素酶的上游,从而构建出一个能表达P53萤火虫荧光素融合蛋白的p53FL/IRES/RL双荧光报告载体。转染该报告载体后,检测被表达的P53荧光素融合蛋白是否被MDM2降解、该融合蛋白的亚细胞定位和它对p53特异性启动子的诱导。结果：成功构建出p53双荧光报告载体。该载体在宿主细胞内表达的P53荧光素融合蛋白能被MDM2降解;主要分布于细胞核;具有野生型p53的转录活性。结论：新构建的p53双荧光报告载体p53FL/IRES/RL能有效模拟野生型p53的功能,适用于高通量筛选调节P53蛋白含量的药物、基因或化合物。     

大鼠Caspase 8基因启动子荧光素酶报告质粒的构建及其与IRF-1结合位点的鉴定

目的:构建大鼠Caspase 8基因启动子(全长和截短)荧光素酶报告质粒,并观察在人胚肾细胞(HEK293)中,过表达干扰素调节因子-1(interferon regulatory factor-1,IRF-1)对Caspase 8基因启动活性的影响?同时,筛选其可能的IRF-1结合位点?方法:采用PCR技术,扩增出大鼠Caspase 8基因启动子序列(-1136~+101 nt),将Caspase 8基因启动子插入到荧光素酶报告基因载体pGL3-basic中?将Caspase 8基因启动子全长荧光素酶报告质粒(pGL3-Caspase 8-FL)和大鼠野生型IRF-1表达质粒(pcDNA3.1-IRF-1)共转染HEK293细胞,检测其荧光素酶活性,确定IRF-1对Caspase 8基因的启动作用?另用生物信息学软件预测Caspase 8基因启动子上IRF-1潜在的结合位点,并构建Caspase 8基因启动子截短的荧光素酶报告质粒(即pGL3-Caspase 8-1~4)?将上述Caspase 8基因启动子全长和各截短的荧光素酶报告质粒和IRF-1过表达质粒共转染HEK293细胞,再行荧光素酶活性测定,筛选IRF-1的结合位点?结果:菌液PCR及核酸测序证实,上述荧光素酶报告质粒均构建成功?将pGL3-Caspase 8-FL和pcDNA3.1-IRF-1共转染HEK293细胞发现,Caspase 8基因启动子活性显著增加?而将pGL3-Caspase 8-FL?pGL3-Caspase 8-1~4和pcDNA3.1-IRF-1共转染HEK293细胞后证实,pGL3-Caspase 8-4的启动活性显著低于pGL3-Caspase 8-2和pGL3-Caspase 8-3?提示IRF-1可能结合在Caspase 8基因启动子的-336~-136 nt区域?结论:本实验成功构建了大鼠Caspase 8基因启动子全长及截短荧光素酶报告质粒,并初步筛查出IRF-1在Caspase 8基因启动子上的结合区域?     

Low density lipoprotein receptor up-regulation

Cholesterol homeostasis in animal cells is attained by balancing extracellular cholesterol uptake through low density lipoprotein receptors (LDLr) with de novo intracellular cholesterol biosynthesis. Maintaining appropriate cholesterol levels is critical for health as high levels can lead to atherosclerosis. Individuals with high cholesterol levels are currently treated with HMG-CoA reductase inhibitors that prevent cholesterol biosynthesis and increase production of LDLr, allowing increased uptake of cholesterol from plasma. However, direct up-regulation of LDLr synthesis would lead to the lowering of LDL cholesterol and could provide an alternative treatment for hypercholesterolaemia and provide additional benefit for those not adequately treated by statins. This article reviews compounds that increase LDLr activity by mechanisms that are postulated to have a direct effect at stimulating LDLr gene expression and not secondary effects as a consequence of inhibiting cholesterol biosynthesis. The mechanisms by which these compounds stimulate LDLr activity are novel and their interactions at the molecular level remain to be elucidated. Detailed understanding of these interactions and other factors involved in the regulation of the LDLr gene holds great promise for the discovery of superior agents for the treatment of hypercholesterolaemia     

雌激素受体Arg548／Cys548基因突变导致受体的高敏感性

目的：研究雌激素受体新突变Arg548／Cys548对受体介导的下游基因表达调控的影响,并探讨其机理和在女孩性早熟中的作用。方法：利用已构建的雌激素受体反应元件报道质粒pGL3-promoter-ERE,分别与野生型ESR1表达质粒PsG5-wtER和定点突变受体表达质粒PSG5-mutER共转染cMF-7和MDA—MB-231细胞,转染后加入雌激素、类似物和拮抗物处理,检测转染细胞的荧光素酶活性值。结果：转染突变型受体的CMF-7和MDA-MB-231细胞的荧光素酶活性值明显升高,在生理浓度雌激素及类似物植物类雌激素异黄酮刺激下,Cys548突变型受体基因转染比野生型受体转染的CMF-7和MDA231细胞均表现出显著强烈的增加萤火虫荧光素酶的活性,表现高敏感的特性;单独加入TAM后荧光素酶活性值没有变化,而同时加入E2和TAM后荧光素酶活性值比加入E2的荧光素酶活性值则明显下降。结论：Cys548突变受体在体外具有较高的敏感性,对药物雌二醇及类似物反应敏感,拮抗剂TAM对受体的活性没有抑制作用,却能竞争性降低雌激素及类似物的作用。     

Immunogenicity and protective efficacy of adenoviral and subunit RSV vaccines based on stabilized prefusion F protein in pre-clinical models

Respiratory Syncytial Virus (RSV) remains a leading cause of severe respiratory disease for which no licensed vaccine is available. We have previously described the derivation of an RSV Fusion protein (F) stabilized in its prefusion conformation (preF) as vaccine immunogen and demonstrated superior immunogenicity in naive mice of preF versus wild type RSV F protein, both as protein and when expressed from an Ad26 vaccine vector. Here we address the question if there are qualitative differences between the two vaccine platforms for induction of protective immunity. In naïve mice, both Ad26.RSV.preF and preF protein induced humoral responses, whereas cellular responses were only elicited by Ad26.RSV.preF. In RSV pre-exposed mice, a single dose of either vaccine induced cellular responses and strong humoral responses. Ad26-induced RSV-specific cellular immune responses were detected systemically and locally in the lungs. Both vaccines showed protective efficacy in the cotton rat model, but Ad26.RSV.preF conferred protection at lower virus neutralizing titers in comparison to RSV preF protein. Factors that may contribute to the protective capacity of Ad26.RSV.preF elicited immunity are the induced IgG2a antibodies that are able to engage Fcγ receptors mediating Antibody Dependent Cellular Cytotoxicity (ADCC), and the induction of systemic and lung resident RSV specific CD8 + T cells. These data demonstrate qualitative improvement of immune responses elicited by an adenoviral vector based vaccine encoding the RSV preF antigen compared to the subunit vaccine in small animal models which may inform RSV vaccine development.     

稳定表达人α-分泌酶adam10基因启动子荧光素酶报告基因细胞系的构建研究

目的 构建携带adam10基因启动子的荧光素酶报告载体,筛选稳定表达细胞系并分析其活性.方法 提取人神经母细胞瘤细胞(SH-SY5Y细胞)基因组DNA,以其为模板,PCR扩增adam10基因启动子并克隆至荧光素酶报告载体pGL4.17中,构建adam10基因启动子荧光素酶报告载体pGL4.17-adam10,将其转染SH-SY5Y细胞(无启动子的pGL4.17载体作阴性对照,带有CMV启动子的pGL4.51载体作阳性对照),经G418进行稳定表达株的筛选,用1μmol/L维甲酸处理细胞4d后检测其荧光活性.结果 成功扩增到438 bp的adam10基因启动子,pGL4.17-adam10经PCR和双酶切鉴定均正确.SH-SY5Y细胞被该载体转染后经G418筛选得到稳定表达adam10基因启动子的细胞株,经检测具有较强的转录活性;1μmol/L雏甲酸能诱导adam10基因启动子高效表达.结论 成功构建了人adam10基因启动子荧光素酶报告载体,adam10基因启动子在SH-SY5Y细胞中能稳定表达,为深入研究adam10基因的表达调控、多态性分析及其高通量药物筛选提供基础.     

携带荧光素酶登革亚病毒颗粒的构建和鉴定

目的 拟将荧光素酶基因整合入登革病毒（DENV）亚病毒颗粒（RSPs）中,构建能用于抗体介导的感染增强（ADE）高通量筛选的研究工具。方法 将荧光素酶基因luciferase插入DENV包膜蛋白基因prME的3'端,取代prME第二个跨膜区,构建prME-luc融合基因。用prME-luc融合基因转染293T细胞,在上清中检测携带荧光素酶的登革亚病毒颗粒（RSP-luc）。结果 转染prME-luc的293T细胞可以将RSP-luc释放至培养上清中,共转染野生型prME能够提高RSP-luc的产量。Western-blot技术确认了RSP-luc中含有DENV包膜蛋白和荧光素酶形成的融合蛋白。RSP-luc易于制备并可通过超速离心分离纯化,且可通过测定荧光素酶活性快速定量。体外实验显示RSP-luc能够与Vero细胞、U937细胞以及小鼠腹腔巨噬细胞等DENV靶细胞结合,结合过程可被受体类似物硫酸肝素竞争性抑制,也可被DENV特异性抗体4E11增强。结论 RSP-luc 能够模拟DENV 感染过程,有望成为深入研究DENV 与宿主相互作用及ADE 发生机制的有效工具。