稳定表达小鼠CD40L的NIH3T3细胞系的建立及其在B细胞培养和激活中的应用

该研究构建小鼠CD40L真核表达重组质粒pcDNA3.1-mCD40L,通过电转法将重组质粒转至NIH3T3细胞中。利用G418对转染后细胞进行压力筛选,获得稳定转染细胞株。提取稳定转染细胞株RNA,通过RT-PCR法检测Neo基因的mRNA表达情况。分离稳定转染细胞上清,利用ELISA法检测小鼠CD40L蛋白水平的表达情况。RT-PCR结果显示,Neo基因能够在稳定转染细胞中表达,ELISA结果显示,获得的稳定转染细胞株NIH3T3-mCD40L细胞上清中CD40L的表达量高达1.286 ng/mL。进一步活性研究表明,该细胞系能够在体外与IL-2和IL-21共同作用培养B细胞至14天,并刺激B细胞产生特异性抗体。该细胞系的成功构建,为利用体外B细胞分离培养和活化法分离特异性单克隆抗体奠定了良好的基础。     

稳定整合pTet-on载体小鼠胚胎干细胞株的建立

目的建立稳定整合Tet-on基因的ES-D3细胞系,用于人胰岛素基因(pTRE2-human-Ins)在ES-D3细胞中诱导表达调控的研究。方法通过电穿孔转染的方法,将pTet-on质粒导入ES-D3细胞中,利用G418的药物选择特性,对转染的ES-D3细胞进行压力筛选,用PCR和Southern blot方法进行DNA整合鉴定,并用瞬时转染荧光素酶报告基因(pTRE-Luc)对筛选的Tet-on阳性克隆株的功能进行鉴定。结果经400μg/mL的G418压力筛选后,获得了11个细胞克隆株,特异性核苷酸引物检测细胞基因组DNA,有9个ES-D3细胞株可以扩增出相应的核苷酸片段,部分Tet-on阳性ES-D3株Southern blot鉴定结果表明Tet-on基因片段已整合入ES-D3细胞基因组DNA,荧光素酶报告基因功能鉴定获得1株诱导表达倍率为21.31的ES-D3细胞株,且Tet-on基因阳性ES-D3细胞的形态和生长速度与正常ES-D3细胞没有差异。结论通过电穿孔转染的方法成功地获得1株诱导表达倍率为21.31的高表达ES-D3细胞株,为进行目的基因(pTRE2-human-Ins)在ES-D3细胞中转染和诱导表达打下了基础。     

Tet调控STGC3基因表达的CNE2细胞系裸鼠成瘤实验性研究

STGC3基因是一个新近克隆的肿瘤相关基因,前期的体外实验研究结果表明,STGC3基因在CNE2鼻咽癌细胞系高表达,可明显抑制CNE2的生长增殖.采用Tet/pTRE-STGC3/CNE2细胞系接种于裸鼠皮下,以强力霉素(Dox)诱导STGC3基因高表达,观测STGC3基因高表达对CNE2裸鼠体内成瘤的影响,并探讨其可能作用机制.运用RT-PCR、蛋白质印迹及免疫组织化学方法,分别从mRNA和蛋白质水平,分析瘤组织中STGC3基因的表达;用流式细胞仪检测移植瘤组织内肿瘤细胞的凋亡情况;用免疫组织化学方法,检测移植瘤组织凋亡相关蛋白Bcl-2和Bax的表达.研究结果显示,STGC3蛋白表达主要定位于细胞核内,Dox诱导STGC3基因在Tet/pTRE-STGC3/CNE2细胞系高表达,Tet/pTRE-STGC3/CNE2细胞系裸鼠体内成瘤受到明显抑制,与对照组比较,移植瘤成瘤时间晚、生长慢、肿块小、细胞凋亡率高,Bax蛋白表达增强,Bcl-2蛋白表达减少,差异有显著性意义(P<0.01).此体内实验研究结果与前期体外实验结果一致,进一步证明STGC3基因对肿瘤细胞生长具有抑制作用.     

抗CD3/抗CD20双特异性单链抗体介导的B淋巴瘤细胞体外裂解作用

在构建并成功表达抗CD3/抗CD20双特异性单链抗体(bscCD3×CD20)的基础上,对其在体外介导T淋巴细胞杀伤Ramous B淋巴瘤细胞的生物活性进行了分析。Annexin V/PI(AV/PI)染色和形态学观察及扫描电镜分析表明bscCD3×CD20介导的B淋巴瘤细胞体外裂解作用是通过先诱导靶细胞凋亡而继发坏死、裂解的方式实现的。非放射性细胞毒性分析表明bscCD3×CD20介导的T淋巴细胞杀伤活性随抗体浓度、反应时间和效靶比的升高而增加。在抗体浓度为5μg/mL、作用时间为24h、效靶比为10∶1时,杀伤活性最高可达87·3%。采用美国SuperArray人细胞凋亡芯片检测细胞杀伤起始阶段细胞凋亡相关基因的表达水平变化,许多凋亡相关基因的表达均发生了不同程度的上调或下调,其中ATM基因表达升高了187倍,p53基因升高了15倍,提示ATM-p53途径可能是bscCD3×CD20介导T细胞诱导B淋巴瘤细胞凋亡的主要途径。     

人表皮角质形成细胞自噬功能细胞模型的构建及鉴定

目的: 建立稳定表达GFP-LC3的人永生化角质形成细胞HaCaT细胞系。方法: 将构建的pcDNA3.1-GFP-LC3 真核表达载体转入HaCaT细胞,经G418筛选稳定表达的细胞系。HaCaT细胞中GFP-LC3的表达分别用荧光显微镜与Western blot方法检测,并利用该稳定表达的细胞系观察验证Rapamycin对细胞发生自噬透射电镜超微结构的变化。结果: 获得了3株转染并经G418反复筛选的HaCaT细胞系,在倒置荧光显微镜下观察可见绿色荧光细胞的表达率在95% 以上,Western blot结果证实了GFP-LC3融合蛋白的表达。Western blot和激光共聚焦显微镜均证明Rapamycin可以诱导自噬的发生。透射电镜细胞超微结构的观察表明Rapamycin可以有效地诱导HaCaT-LC3细胞自噬的发生。结论: 成功构建GFP-LC3稳定表达的HaCaT系,该细胞系可以作为研究人角质形成细胞自噬功能的一种细胞模型。     

稳定表达人Eps8基因的胶质瘤U251细胞系的建立

应用亚克隆方法构建pEGFP-C3／Eps8真核表达载体,经测序鉴定后,用脂质体进行胶质瘤U251细胞的转染,应用G418筛选出稳定表达pEGFP-C3／Eps8和pEGFP—C3的细胞系,最后通过Western blot和荧光定位证明印娼在U251细胞中过量表达。本实验成功建立了稳定转染Eps8的U251细胞系,为进一步研究Eps8基因在胶质瘤中的功能奠定了良好的实验基础。     

干扰素膜蛋白Tet-on系统稳定细胞系的建立及对CA16病毒的抑制作用

通过Tet-on调控系统,构建受多西环素诱导表达干扰素诱导的跨膜蛋白(interferon-induced transmembrane proteins 1/2/3,IFITM1/2/3)基因的HeLa细胞系,并初步探索了IFITM蛋白对柯萨奇病毒A16(CA16)的抑制作用.首先将调控质粒pTet-on转染进入HeLa细胞,通过G418筛选出阳性克隆细胞系,在此细胞系基础上共同转染反应质粒pTRE2-IFITM1/2/3和伴侣质粒pTK-Hyg,通过潮霉素筛选出单克隆细胞系,加入多西环素后利用Western印迹筛选出可诱导表达IFITM1/2/3蛋白的单克隆细胞系.使用实时荧光定量PCR(RT-qPCR)检测发现,多西环素诱导表达的IFITM蛋白对不同感染复数(multiplicity of infection,MOI)的CA16具有明显的抑制作用,其中IFITM 3对CA16的抑制效果最为明显.Tet调控IFITM1/2/3基因表达HeLa细胞系的成功建立,为进一步研究IFITM基因的功能及其抗病毒机理提供了一个理想的细胞模型.     

hsBLyS基因在中国仓鼠卵巢细胞中的表达及其在免疫小鼠中诱发的抗体反应

为建立稳定表达人可溶性B淋巴细胞刺激因子(hsBLyS)的中国仓鼠卵巢(CHO)细胞系,从人胎盘cDNA文库中扩增hsBLyS基因,将人红细胞生成素(EPO)信号肽序列和hsBLyS基因重叠延伸为融合基因;融合基因分别插入pcDNA3、pcDNA3.1、pEFneo质粒;磷酸钙共沉淀将表达质粒和标志质粒pSVdhfr,共转染CHOdhfr细胞;选择培养液筛选,经氨甲喋呤选择压力扩增表达,获稳定表达hsBLyS的细胞系,表达量由0.13μg/ml上升至0.55μg/ml;同时利用pEFneo/hsBLyS重组质粒免疫BALB/c小鼠,检测结果表明小鼠产生hsBLyS的特异性抗体。本实验建立了稳定表达hsBLyS的CHO细胞系,对其基因免疫小鼠抗体产生的特点做了初步探讨,为hsBLyS进一步研究奠定了良好的基础     

利用四环素调控系统研究 CHIP 对TGF-β信号通路的抑制性调节

为了研究伴侣分子相互作用蛋白 CHIP 对 TGF-β信号通路的调控,利用四环素基因表达调控系统,建立四环素调控表达 CHIP 的稳定细胞系 (Mv1Lu-Tet off-CHIP). 利用此细胞模型,发现 CHIP 的过量表达可显著降低细胞内 Smad2/3 蛋白水平;荧光素酶报告分析也表明开启 CHIP 蛋白表达可明显降低 Smads 介导的基因转录活性;进一步的免疫印迹结果显示 CHIP 蛋白可明显下调 TGF-β所诱导的下游基因 JunB 的表达 . 上述结果提示 CHIP 可以作为一种新的蛋白质分子抑制性调节 TGF-β信号通路 .     

B19病毒XA株VP1独特区蛋白对Hela细胞凋亡的影响

目的:构建B19病毒XA株VPlu基因的真核表达载体和稳定转染细胞系,探讨B19病毒XA株VPl独特区蛋白对Hela细胞凋亡的影响。方法:采用本课题组前期构建的真核表达载体plRES2-EGFP-Vplu及plRES2-EGFP对照质粒,将其稳定转染至Hela细胞,通过流式细胞术检测EGFP阳性细胞的比例以确定稳定转染的细胞系是否成功构建;提取稳定转染的Hela细胞的总蛋白,通过Western blot检测细胞内凋亡相关基因Caspase3的表达;转染plRES2-EGFP-Vplu及plRES2-EGFP的Hela细胞经过Annexin V和PI的染色后,通过流式细胞术检测其凋亡率。结果:本实验成功构建了plRES2-EGFP-VPlu稳定转染的Hela细胞系,plRES2-EGFP-Vplu稳定转染的Hela细胞中Caspase3的表达较转染对照质粒的Hela细胞明显增加,细胞凋亡率亦显著升高,差异均具有统计学意义(P0.05)。结论:B19病毒XA株VP1独特区蛋白能够显著促进Hela细胞的凋亡。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

医疗机构合理用药评价模型的构建研究

目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。