BCL—2基因表达与乳腺癌抗凋亡及免疫耐受的关系

目的 观察乳腺癌细胞株ＢＣＬ－２基因表达与其耐受肿瘤浸润淋巴细胞（ＴＩＬ）免疫攻击的关系,探索应用ＢＣＬ－２硫代反义寡核苷酸（ＢＣＬ－２ＳＯＮ）治疗乳腺癌的途径。方法 ＢＣＬ－２硫代反义寡核苷酸处理乳腺癌细胞株ＭＣＦ－７,Ｗｅｓｔｅｒｎ印迹法观察其对ＢＣＬ－２表达的抑制;并将ＭＣＦ－７细胞与乳腺标本分离出来的ＴＩＬ共同培养,通过ＪＡＭ试验观察ＴＩＬ诱导ＭＣＦ－７细胞凋亡的情况。结果 ＢＣＬ－２ＳＯＮ处理的ＭＣＦ－７细胞无ＢＣＬ－２表达,并在ＪＡＭ试验中随着ＴＩＬ浓度增加,凋亡细胞也增加,未经处理的对照组可见ＢＣＬ－２表达,ＪＡＭ试验中随着ＴＩＬ浓度增加,凋亡细胞的量无明显变化。结论 ＢＣＬ－２表达的乳腺癌细胞可对抗肿瘤浸润淋巴细胞的免疫攻击,ＢＣＬ－２ＳＯＮ可作为治疗乳腺癌的新途径。     

Fas和β—雌二醇受体融合基因在L929细胞中的表达及活性鉴定

利用ＰＣＲ方法将人Ｆａｓ基因的信号肽、跨膜区、胞内区与人β－雌二醇受体的激素结合结构域基因融合，并插入高效真核表达载体ｐｃＤＮＡ３。用脂质体法转染Ｌ９２９细胞，加入Ｇ４１８４周后，筛选出的转化细胞经Ｗｅｓｔ－ｅｒｎｂｌｏｔ检测证明，该融合基因在Ｌ９２９细胞中得到较高表达。ＭＴＴ法检测进一步表明，在培养基中加入β－雌二醇可有效地诱导转化细胞发生凋亡，ＩＣ５０为１０－１０ｍｏｌ／Ｌ。     

淫羊藿甙逆转转化生长因子β2对LAK,CD3AK细胞的免疫抑 …

目的 探讨淫羊藿甙逆转转化生长因子β２（Ｔｒａｎｓｆｏｒｍｉｎｇ Ｇｒｏｗｔｈ Ｆａｃｔｏｒ β２ＴＧＦβ２）对ＬＡＫ、ＣＤ３ＡＫ细胞的免疫抑制作用及其机制。方法 采用ＭＴＴ法,ＲＴ－ＰＣＲ和流式细胞术。结果 淫羊藿降转受ＴＧＦβ２抑制的ＬＡＫ和ＣＤ３ＡＫ细胞的杀伤活性,并能部分恢复受ＴＧＦβ２抑制的ＬＡＫ细胞表面ＩＬ－２Ｒα表达和ＣＤ３ＡＫ细胞内穿孔素ｍＲＮＡ水平,以及ＣＤ３ＡＫ细胞的增殖活性。     

合成多肽体外诱导乙肝病毒抗原特异性CTL杀伤机制研究

为探讨合成多肽体外诱导乙肝病毒抗原特异性Ｔ细胞杀伤机制，应用免疫组化检测ＨＧＶ－ＣＴＬｓＦａｓ配体表达情况，燕分析培养上清一氧化氮含量与细胞毒活性的关系。结果显示，ＨＢＶ－ＣＴＬｓ对转染ＨＢＶ ＤＮＡ的肝癌细胞存在明显的特异性细胞毒活性，其Ｆａｓ配体表达阳性率分别为５８％，５６％，明显高于ＣＤ３－ＡＫ细胞组，细胞培养上清ＮＯ含量动态分析显示，ＨＢＶ－ＣＴＬｓ细胞培养上清ＮＯ含量与细胞毒活性存在正相     

gadd153基因对卵巢癌细胞生长抑制作用的研究

目的　研究生长抑制ＤＮＡ损伤基因（ｇｒｏｗ ｔｈ ａｒｒｅｓｔ ａｎｄ ＤＮＡ ｄａｍ ａｇｅ, ｇａｄｄ）对卵巢癌细胞生长抑制和凋亡的作用。　方法　ＲＴ－ＰＣＲ鉴定卵巢癌ＳＫＯＶ３ 和３ＡＯ细胞株ｇａｄｄ１５３ 基因表达。通过目的基因的克隆、载体构建技术,将目的基因ｇａｄｄ１５３ 重组于ｐｌＸＳＮ－ｎｅｏ 逆转录病毒表达载体;构建的ｐＬＸＳＮ－ｇａｄｄ１５３载体采用脂质体（ｌｉｐｏｆｅｃｔｉｎ）（ＤＯＴＡＰ）的方法,分别转染ＳＫＯＶ３ 和３ＡＯ细胞株;经Ｇ４１８ 抗性筛选;ＲＴ－ＰＣＲ表达鉴定;足叶乙甙（ＶＰ１６）诱导,采用流式细胞仪分析（ＦＣＭ）的方法检测转染前后肿瘤细胞的生长抑制和凋亡。　结果　ＳＫＯＶ３－ｇａｄｄ１５３ 细胞生长抑制在Ｇ１／Ｇ０ 期,部分细胞进入凋亡的状态;３ＡＯ－ｇａｄｄ１５３ 细胞生长抑制,未引起凋亡。　结论　转染ｇａｄｄ１５３ 基因的肿瘤细胞系,诱导表达后可诱发肿瘤细胞生长抑制在Ｇ１／Ｇ０期,并有细胞进入凋亡状态。证实ｇａｄｄ１５３ 基因参与了细胞生长抑制和凋亡过程。     

Fas介导凋亡的免疫学研究进展

激活Ｔ细胞表达Ｆａｓ配体（ＦａｓＬ），ＦａｓＬ与靶细胞Ｆａｓ结合，可使其凋亡。Ｆａｓ介导凋亡是Ｔ细胞杀伤途径之一。Ｆａｓ－ＦａｓＬ介导的淋巴细胞凋亡有免疫下调作用。其中主要参与外周Ｔ细胞克隆清除和活化Ｔ细胞凋亡。当Ｆａｓ介导凋亡功能缺失或功能过强均可出现免疫病理现象。     

人胰岛素样生长因子1的真核细胞表达及其鉴定

目的 构建人胰岛素样生长因子１（ＩＧＦ－１）的真核细胞表达质粒。方法 用ＰＣＲ方法从人的肝细胞ｃＤＮＡ文库中克隆出ＩＧＦ－１ｃＤＮＡ,然后定向插入真核细胞表达载体ｐｃＤＮＡ３中,并用脂质体方法转染ＣＯＳ７细胞。用ＥＬＩＳＡ法和人胚肺纤维母细胞以及ＮＩＨ３Ｔ３纤维细胞增殖法分别测定转染细胞上清液中ＩＧＦ－１的含量和生物活性。结果 重组的真核细胞表达质粒ｐｃＤＮＡ３－ＩＧＦ－１所含的ＩＧＦ－１ｃＤＮＡ序列和插入方向均正确,其转染的ＣＯＳ７细胞分泌较高浓度的ＩＧＦ－１,并且具有明显促进纤维细胞增殖的能力。结论 本实验所构建的重组真核细胞表达质粒ｐｃＤＮＡ３－ＩＧＦ－１能够高效表达有活性的ＩＧＦ－１,对进一步研究ＩＧＦ－１体内表达的生理和病理作用有一定意义。     

鼠抗人Fas单克隆抗体的制备及鉴定

采用Ｊｕｒｋａｔ细胞Ｂａｌｂ／ｃ小鼠制备１株抗人ＦａｓｍＡｂ２Ａ１,它能特异性识别Ｊｕｒｋａｔ,Ｒａｊｉ,ＴＨＰ－１细胞膜表面５０ＫＤ左右的蛋白,并能与ＳｒＦａｓ标准蛋白反应,其识别的细胞膜蛋白与单抗特异性抗人Ｆａｓ ＰｃＡｂＮ－１８相一致。ｌｅｑ     

人Fas—L基因的克隆和表达

应用 Ｒ Ｔ Ｐ Ｃ Ｒ 技术, 从激活的人外周血淋巴细胞总 Ｒ Ｎ Ａ 中扩增出一条长约８６０ｂｐ 的人 Ｆａｓ Ｌｃ Ｄ Ｎ Ａ, 通过逆转录病毒表达系统, 在 Ｎ Ｉ Ｈ３ Ｔ３ 细胞中得到表达。以 Ｆａｓ 阳性细胞株 Ｈ Ｌ６０ 为靶细胞, 检测 Ｆａｓ Ｌ 的功能, 结果表明, 表达于 Ｎ Ｉ Ｈ３ Ｔ３ 细胞上的 Ｆａｓ Ｌ 可诱导 Ｈ Ｌ６０ 细胞的凋亡。     

肺癌、结肠癌中Fas配体“假”受体的基因扩增

Ｆａｓ 配体（ＦａｓＬ）由激活的Ｔ细胞和ＮＫ细胞产生,它通过死亡受体Ｆａｓ诱导靶细胞发生细胞凋亡。本研究发现了一种可溶性的ＦａｓＬ的“假”受体－ＤｃＲ３（ｄｏｃｏｙ ｒｅｃｅｐｔｏｒ ３）,它可通过与ＦａｓＬ结合从而抑制ＦａｓＬ介导的细胞凋亡。 作者从胎肺中分离出一段未知的ｃＤＮＡ序列,它和ＴＮＦＲ基因超家族具有同源性,其编码的多肽约含３００个氨基酸,并在Ｎ－末端的先导序列后紧邻有４个保守的半胱氨酸富集区,这一特点与ＴＮＦＲ家族成员非常相似。与ＴＮＦＲ的同源体Ｐｓｔｅｏｐｒａｔｅｇｅｒｉｎ（ＯＰＧ）…     

Suppression of FasL expression in tumor cells and preventing tumor necrosis factor-induced apoptosis by adenovirus 14.7K is an effective escape mechanism for immune cells

To elucidate if the Fas/FasL signal pathway participates in the immune escape of tumor cells, and if contemporary Fas/FasL and tumor necrosis factor (TNF))-induced apoptosis is better for immune cell survival than just blocking Fas/FasL-induced apoptotic signal. FasL expression in mouse H22 hepatocellular cancer cells was suppressed by the siRNA technique. The wild-type Ad5 14.7K gene was amplified by polymerase chain reaction and transduced into Jurkat T-cells. Apoptosis of target Jurkat cells was detected by flow cytometry. TNF-alpha in the culture supernatant of H22 cells by ELISA was seen. FasL and 14.7K gene expression in stably transfected or transduced clones were determined by Western blotting. As a result, FasL expression in H22 cells was down-regulated after stable transfection with a plasmid encoding antisense FasL cDNA. Down-regulation of FasL expression in H22 cells had no effect on tumor growth in vitro. There was an apparent decrease in the number of apoptotic Jurkat T-cells after coculture with transfected H22 cells, relative to coculture with FasL-expressing untransfected cells. Compared with untransduced Jurkat cells, apoptotic rates in 14.7K-transduced Jurkat cells were significantly reduced in three different E/T ratios (P < 0.01), respectively. We conclude that Fas/FasL signal pathway participates in the immune escape of tumor cells by inducing immune cells apoptosis. Reducing the expression of FasL in tumor cells can decrease the apoptotic rate of immune cells, further blocking the apoptotic signal pathway of immune cells by preventing TNF-induced apoptosis can increase the survival of immune cells.     

ICA、PJA逆转人高转移肺癌细胞Fas/FasL途径免疫逃逸机制的研究

目的：研究ICA、PJA对人高转移肺癌细胞PG细胞免疫逃逸的逆转作用。方法：MTT法检测ICA、PJh对PG细胞增殖的影响以及对CD3AK杀伤敏感性的影响。流式细胞仪检测细胞表面分子Fas、FasL表达水平和细胞凋亡。应用PG细胞与Jurkat T细胞其培养的方法体外研究FasL诱导T淋巴细胞凋亡的作用。结果：PG细胞高表达FasL，低表达Fas，对CD3AK细胞杀伤敏感性较低，并在与Jurkat T细胞共培养中诱导高表达Fas的Jurkat T细胞凋亡。：ICA、PJA对PG细胞有明显的增殖抑制作用。ICA可明显提高PG细胞Fas的表达率。ICA、PJA可明显降低PG细胞FasL的表达率。ICA、PJA可使PG细胞与Jurkat T细胞共培养中，降低Jurkat T细胞的凋亡率。ICA、PJA可提高CD3AK细胞对PG细胞的杀伤活性。结论：ICA、PJA可逆转人高转移肺癌细胞PG通过Fas／FasL途径逃避机体免疫活性细胞的攻击。     

特异性ASODN抑制Fas表达降低FasL介导细胞凋亡的研究

为了研究特异性Fas反义寡核苷酸(ASODN)对T细胞Fas表达及肝癌细胞诱导其凋亡的抑制作用,用脂质体介导法将Fas ASODN导入Jurkat T细胞,并通过用流式细胞术、RT-PCR及与肝癌细胞共培养方法研究Fas ASODN对T细胞Fas表达、Fas mRNA水平及凋亡的影响。结果显示:①Hep G2.2.15细胞表达有功能的FasL,可诱导Jurkat细胞凋亡;②Jurkat细胞转染Fas ASODN后,Fas mRNA降低;细胞表面Fas表达下降;与Hep G2.2.15细胞共培养后的凋亡率下降。表明Fas ASODN转染可以部分逆转肝癌细胞对T细胞的凋亡诱导作用。     

Fas/FasL途径介导的人肺癌细胞免疫逃逸

目的：观察在3种人肺癌细胞（A549、EBC-1、LCSC）和人T细胞(Jurkat) Fas/FasL表达情况，探讨人肺癌细胞免疫逃逸及反杀伤作用与Fas/FasL途径的关系。 方法： 用FACScan、RT-PCR方法检测Fas/FasL蛋白及mRNA表达；以荧光染色法观察细胞调亡；用台盼蓝拒染法检测细胞存活。 结果： 3种人肺癌细胞及T-细胞系(Jurkat)均表达 Fas及 FasL；肺癌细胞与Jurkat细胞共培养时，肺癌细胞可导致Jurkat细胞生长抑制(P<0.05)及凋亡；在共培养体系中加入FasL中和性抗体NOK1，可封闭肺癌细胞对Jurkat细胞的生长抑制作用(P>0.05)。 结论： Fas/FasL途径可介导上述3种人肺癌细胞对Jurkat细胞的生长抑制及致凋亡作用；中和性抗体可有效阻断Fas信号转导途径，抑制肿瘤细胞的反杀伤作用，有效保护免疫系统。     

CpG-ODN下调HeLa细胞功能性Fas配体的表达

为观察CpG-ODN对宫颈癌细胞系HeLa细胞Fas配体(FasL)表达水平的影响,探讨其对由HeLa细胞Fas-FasL途径诱导的淋巴细胞凋亡作用。采用实时荧光RT-PCR方法检测HeLa细胞、正常宫颈上皮细胞中FasL和Jurkat T淋巴细胞中Fas的表达水平,应用HeLa细胞与Jurkat细胞共培养的方法体外研究HeLa细胞FasL诱导T淋巴细胞凋亡作用。结果显示:①HeLa细胞、正常宫颈上皮细胞中FasL表达阳性,其表达水平分别是(0.99±0.05)、(0.68±0.03),差别具有统计学意义(P=0.0007);Jurkat细胞Fas表达呈阳性;②HeLa细胞与Jurkat细胞共培养后Jurkat细胞的凋亡率为(38.23%±4.98%),应用抗体NOK-2中和HeLa细胞的FasL后,Jurkat细胞凋亡率减少为(3.54%±1.61%),两者相比,差别有显著性意义(P=0.0001);③HeLa细胞用CpG-ODN处理前后FasL的表达水平分别是(0.99±0.05)、(0.79±0.04),差别有统计学意义(P=0.005);CpG-ODN预处理的HeLa细胞与Jurkat细胞共培养后Jurkat细胞凋亡率为(6.41%±2.81%),而没有用CpG-ODN预处理的HeLa细胞与Jurkat细胞共培养Jurkat细胞凋亡率为(29.23±6.85)%,二者的差别有统计学意义(t=13.39,P=0.006)。HeLa细胞可能通过表达FasL主动诱导T淋巴细胞凋亡从而在肿瘤的免疫逃逸中发挥作用,CpG-ODN可通过下调FasL的表达而减少肿瘤细胞主动诱导的T淋巴细胞凋亡。     

反义RNA阻断Hep G2细胞FasL的表达及功能研究

应用分子克隆技术将人FasLcDNA片段反向插入逆转录病毒载体pLXSN ,构建重组质粒pL (hFasL AS )SN ,转染包装细胞PA317后获得FasL反义RNA重组逆转录病毒表达载体假病毒上清 ,经NIH3T3细胞检测其感染滴度后转染肝癌细胞株HepG2细胞并筛选建系 ,命名为HepG2 hFasL AS。半定量RT PCR检测显示HepG2 FasL AS细胞FasL的mRNA明显少于正常HepG2细胞 ;FACS检测显示HepG2 FasL AS细胞FasL的表达与HepG2细胞相比显著下降 ;同时 ,HepG2 FasL AS细胞导致HL 6 0细胞凋亡能力有所下降。表明人FasL反义RNA重组逆转录病毒表达载体能抑制转染细胞FasL的表达并下调其致凋亡功能     

Induction of FAS ligand expression in a human hepatoblastoma cell line by HCV core protein

Tumour cells and virus infected cells expressing Fas ligand (FasL) can evade immune surveillance by inducing apoptosis in T cells expressing Fas. In order to characterise a possible role of hepatitis C virus (HCV) core protein in similar mechanisms during HCV infection, we investigated Fas ligand expression and activity in a human hepatoblastoma cell line (HepG2) constitutively expressing this protein.Strong FasL induction was detected by immunoblotting and flow cytometry analysis in the core expressing cell lines Hep39. In contrast, vector transfected cells or cell lines expressing HCV E1-E2 proteins did not show FasL expression. Co-cultivation experiments of Hep39 cells with a Fas-sensitive T cell line indicated that FasL induced by the core protein had apoptotic activity toward target cells. Effect of the core protein on induction of FasL promoter was further examined by co-transfection of HepG2 cells with core-bearing plasmid and a vector in which luciferase gene expression is driven by human FasL promoter. Results of the luciferase assay indicated a positive regulation of FasL promoter by the core protein. In conclusion, HCV core protein plays a role in the induction of functional FasL in hepatoblastoma cell line and apoptosis in a target T cell line expressing Fas. Similar mechanisms may contribute, in vivo, to establishment of chronic infection and development of hepatocellular carcinoma (HCC).     

脱氢表雄酮诱导CD4+T细胞系Jurkat细胞凋亡的初步探索

为研究脱氢表雄酮(DHEA)对Jurkat细胞增殖活性和凋亡的影响,用不同浓度的DHEA处理Jurkat细胞12 h、24 h后,用MTT法测定细胞活性;Hoechst染色观测细胞形态的改变;碘化丙啶(PI)染色检测细胞凋亡;Annexin V/PI双染法检测细胞膜变化;DNA阶梯状电泳分析细胞DNA断裂;荧光显微镜分析细胞线粒体膜电位变化;并用RT-PCR和流式检测凋亡时细胞中Fas和FasL的mRNA和蛋白表达的情况。结果显示,DHEA在10~(-7)mol/L时对Jurkat细胞有显著的增殖抑制作用(P<0.05)和诱导凋亡效果,细胞凋亡率比对照组分别升高2.48%和2.52%;Annexin V/PI双染法检测,处理组凋亡细胞比率比对照组也明显增加;且随着DHEA剂量的增加细胞线粒体膜电位倒塌明显增强,Fas和FasL的mRNA和蛋白水平也随之增加。以上结果表明,DHEA在高浓度时对Jurkat细胞有一定的抑制增殖并诱导其凋亡的作用,Fas/FasL通路和膜电位的改变在此机制中发挥了相应的作用。     

Expression of Fas and Fas ligand and apoptosis in tumor-associated lymphocytes and in tumor cells from malignant pleural effusions

The CD95 (APO-1/Fas)-Fas ligand (FasL) system is an important mediator of antitumor T cell cytotoxicity. The aim of the current study was to assess its significance in human cancer. Malignant effusions were selected as an environment allowing direct cell-to-cell contact in a fluid phase. Malignant pleural effusions collected from 23 patients with metastatic carcinoma of the bronchus, ovary, stomach or breast were examined by means of flow cytometry. The expression ofFas and FasL, probed with the appropriate antibodies, apoptosis of tumor cells and the characteristics of tumor-associated lymphocytes (TAL) were determined by TUNEL reaction in malignant and nonmalignant (control) effusions. All malignant cells had partially or completely lost the expression of CD95 and expressed an elevated level of FasL. In contrast, TAL obtained from malignant pleural effusions demonstrated a marked decrease in the expression of surface FasL and an increase in surface-bound Fas. The percentage of apoptotic malignant cells was significantly decreased, as compared to TAL and lymphocytes from nonmalignant pleural effusions. There were also differences in the expression of Fas and FasL among mononuclear cells from malignant and nonmalignant pleural effusions. The ability of TAL from malignant pleural effusions to induce apoptosis of K562 cells was diminished, as compared to peripheral blood lymphocytes. Taken together, these data suggest that tumor cells in the microenvironment of malignant pleural effusions can evade immune attack by downregulation of the CD95 receptor and by killing lymphocytes through the expression of FasL. These results confirm earlier reports which showed that lymphocytes from a tumor microenvironment appear to have a depressed cytotoxic action.