消化系恶性肿瘤患者血清与腹水中细胞因子活性变化

目的研究消化系恶性肿瘤（ＤＭＴ）患者血清与腹水中内源性ＩＬ２,ＩＬ６,ＩＬ８,ＴＮＦα和ＩＦＮγ的生物学活性．方法应用ＥＬＩＳＡ法检测了１５例ＤＭＴ患者（肝癌１１例,胆总管癌１例,胰腺癌１例,胃癌１例,直肠癌１例）血清与腹水中５种细胞因子活性,并与６例肝硬变（ＬＣ）患者和８例正常成人进行了比较分析．结果ＤＭＴ患者血清ＩＬ２,ＩＬ６的生物学活性显著低于ＬＣ（Ｐ＜００５）;腹水中ＩＬ２,ＩＬ８活性显著低于ＬＣ组（Ｐ＜００１）,而ＩＬ６和ＩＦＮγ活性则高于ＬＣ组（Ｐ＜００１,００５）．ＤＭＴ患者血清中ＩＬ６,ＩＬ８活性明显高于正常成人组（Ｐ＜００５）;ＩＬ２,ＩＦＮγ则低于正常成人组,但缺乏显著性．肝癌血清和腹水中ＩＬ２活性显著高于非肝癌组（Ｐ＜００５）;而ＩＬ６活性则相对降低（Ｐ＜００５）．结论恶性肿瘤患者血清中ＩＬ２和ＩＦＮγ活性低于正常人,是ＤＭＴ患者抗肿瘤免疫功能缺陷的标志．ＩＬ６对于预测ＤＭＴ患者的预后具有重要的意义     

肝炎后肝硬变肝损害与细胞免疫功能(英文)

目的研究肝炎后肝硬变（ＰＨＣ）患者的细胞免疫状态及其与肝功能损害的关系．方法５１例ＰＨＣ患者，包括ＣｈｉｌｄＰｕｐｈＡ级２０例、Ｂ例１８例、Ｃ级１３例和２２例健康对照者，外周血经用ＦｉｃｏｌＨｙｐａｑｕｅ梯度离心分离单个核细胞后，采用３ＨＴｄＲ掺入技术测定了淋巴细胞转化，ＩＬ２和ＮＫ细胞活性．结果在ＰＨＣ患者淋巴细胞转化指数（ＳＩ）、ＩＬ２活性（ＳＩ）和ＮＫ细胞活性（％）较对照组均明显降低（１８１±１３０ＶＳ３４９±２１７，Ｐ＜００１；８１±６０ＶＳ１３６±５８，Ｐ＜００１；４０３±２１７ＶＳ６１３±２０５，Ｐ＜００１）．免疫功能缺陷与ＣｈｉｌｄＰｕｐｈ分级有关，Ｃ级明显低于Ａ、Ｂ级（Ｐ＜００１），Ｂ级低于Ａ级（Ｐ＜００５）．结论ＰＨＣ患者存在细胞免疫功能缺陷，且与肝损害程度有关．     

乙型肝炎及原发性肝癌患者sIL-2R的变化

目的探讨ｓＩＬ２Ｒ水平与乙型肝炎病情的关系及其在原发性肝癌早期诊断中的价值．方法以ＥＬＩＳＡ法动态检测１１３例乙型肝炎及６例原发性肝癌患者ｓＩＬ２Ｒ水平，另选３１例健康体检者作对照组．结果以ｑ检验、ｔ检验进行统计学处理（微机处理，ＰＯＭＳ２００版）．结果各型乙型肝炎ｓＩＬ２Ｒ水平均显著高于正常对照（ＮＣ）组（Ｐ＜００１），其顺序依次为：ＨＣＣ＞ＣＳＨ＞ＣＨ（ＩＩ）＞ＬＣ＞ＣＨ（ＩＩ）＞ＡＨ＞ＣＨ（Ｉ）＞ＮＣ．ＨＣＣ组ｓＩＬ２Ｒ均值达正常值的２倍以上，且与ＣＨ（Ｉ），ＣＨ（Ｉ），ＡＨ间存在显著性差异（Ｐ＜００１，＜００５及＜００５）；ＣＨ（ＩＩ）组显著高于ＣＨ（Ｉ）组（Ｐ＜００１）．ＨＢｅＡｇ阳性组及ＨＢＶＤＮＡ阳性组ｓＩＬ２Ｒ水平显著高于阴性组．结论ｓＩＬ２Ｒ是监测乙型肝炎病情、ＨＢＶ复制及诊断早期原发性肝癌的一项敏感标志．     

SLE 患者 PBMC 分泌IL-3 活性水平的初步研究

目的：为了研究ＳＬＥ患者ＰＢＭＣ分泌ＩＬ３的能力。方法：采用ＭＴＴ比色方法，用ＩＬ３依赖株（ＴＦ１）分别测定了１５例活动期、１５例缓解期ＳＬＥ患者和正常对照者ＰＢＭＣ培养上清中ＩＬ３的活性水平。结果：ＳＬＥ患者ＰＢＭＣ自发分泌ＩＬ３的活性水平显著高于正常人（Ｐ＜０００１），活动期和缓解期患者之间无显著性差异（Ｐ＞００５），经ＰＨＡ刺激后ＳＬＥ患者和正常人ＰＢＭＣ分泌ＩＬ３的活性水平均显著增加（Ｐ＜０００１），在ＳＬＥ病人中，以伴发显著血小板减少的５例患者ＰＢＭＣ分泌ＩＬ３的活性水平最低。结论：ＩＬ３可能参与ＳＬＥ的致病过程，且和ＳＬＥ患者血小板减少有关。     

哮喘患者外周血单个核细胞中白细胞介素-6 mRNA表达与气道炎症的研究

目的探讨外周血单个核细胞（ＰＢＭＣ）中白细胞介素（ＩＬ）６ｍＲＮＡ表达与血嗜酸细胞阳离子蛋白（ＥＣＰ）和１秒用力呼气容积占用力肺活量比值（ＦＥＶ１％）的关系。方法对１２例过敏性哮喘发作期患者、８例缓解期患者及９例健康人，采用ＲＴＰＣＲ法和图像分析半定量法检测ＰＢＭＣ中ＩＬ６ｍＲＮＡ的表达水平及ＥＣＰ和ＦＥＶ１％。结果发作期患者ＩＬ６ｍＲＮＡ的表达明显高于缓解期患者和健康人（Ｐ＜００１），而缓解期患者无明显升高。发作期患者ＩＬ６ｍＲＮＡ的表达水平与血清ＥＣＰ呈中度正相关（ｒ＝０６７９，Ｐ＜００１），而与ＦＥＶ１％呈中度负相关（ｒ＝－０５８９，Ｐ＜００５）。结论过敏性哮喘发作期患者ＰＢＭＣ中ＩＬ６ｍＲＮＡ表达水平显著增强。其气道炎症程度与ＩＬ６基因转录增强有关     

胃癌浸润性淋巴细胞的细胞表型及杀伤活性

目的和方法：本实验用９例胃癌患者ＴＩＬ和ＩＬ２在体外共同孵育后，用流式细胞仪分析胃癌ＴＩＬ的细胞表型特征。结果：ＴＩＬ细胞表型特征是以ＣＤ３为主，ＣＤ４／ＣＤ８为０８３，ＮＫ细胞１６３±３６％。经白细胞介素２（ＩＬ２）激活２０天后，ＣＤ３减少，ＣＤ４／ＣＤ８为１８５，ＮＫ细胞数量增至４１３±１３７％，Ｐ＜００１。ＬＤＨ释放法测定激活后的ＴＩＬ对自体胃癌细胞杀伤率比培养初期高３７４倍，变比对同时培养的７９０１胃癌细胞杀伤率高１７５倍。对自体和异体胃癌细胞杀伤作用均显著高于ＬＡＫ细胞，且具有靶细胞特异性。结论：结果表明胃癌ＴＩＬ对胃癌细胞杀伤作用，可能与ＮＫ细胞数量增多，导致胃癌细胞凋亡有关     

哮喘气道炎症粘附机制的实验研究

目的评价细胞间粘附分子１（ＩＣＡＭ１）、Ｐ选择素在哮喘气道炎症粘附机制中的作用,进一步阐明哮喘的发病机理。方法用酶联免疫吸附试验、肺组织免疫组化检查和呼吸生理学方法系统观察正常组和哮喘组豚鼠各项指标。结果（１）哮喘组豚鼠肺潮气量、动态肺顺应性（Ｃｄｙｎ）和肺气道阻力与对照组比较差异有显著性（Ｐ＜０．０１及Ｐ＜０．０５）。（２）哮喘组豚鼠血浆和肺泡灌洗液（ＢＡＬＦ）可溶性ＩＣＡＭ１（ｓＩＣＡＭ１）、可溶性Ｐ选择素、血清和ＢＡＬＦ嗜酸粒细胞阳离子蛋白（ＥＣＰ）与对照组比较,差异有显著性（Ｐ＜０．０１）;ＢＡＬＦ中白细胞介素８（ＩＬ８）与对照组比较差异也有显著性（Ｐ＜０．０１）。（３）哮喘组豚鼠肺组织（气道上皮和血管内皮）ＩＣＡＭ１和ＩＬ８表达与对照组比较,差异有显著性（Ｐ＜０．０１）。结论ＩＣＡＭ１、Ｐ选择素、ＩＬ８、ＥＣＰ参与介导了哮喘气道炎症的粘附过程     

细胞因子对树突状细胞抗肝癌作用的影响

目的研究人血树突状细胞（ＤＣ）和细胞因子ＴＮＦ,ＧＭＣＳＦ或ＩＦＮγ联合ＤＣ对淋巴因子和ＰＨＡ激活的杀伤细胞（ＬＰＡＫ细胞）体外杀伤人肝癌细胞株ＢＥＬ７４０２的影响．方法实验分为Ｌ组（ＬＰＡＫ）,Ｄ组（ＬＰＡＫ＋ＤＣ）,Ｔ１组（ＬＰＡＫ＋ＤＣ＋ＴＮＦ５０００ｋＵ／Ｌ）,Ｔ２组（ＬＰＡＫ＋ＤＣ＋ＴＮＦ５００ｋＵ／Ｌ）,Ｇ１组（ＬＰＡＫ＋ＤＣ＋ＧＭ－ＣＳＦ５００ｋＵ／Ｌ）,Ｇ２组（ＬＰＡＫ＋ＤＣ＋ＧＭ－ＣＳＦ１００ｋＵ／Ｌ）,Ｉ１组（ＬＰＡＫ＋ＤＣ＋ＩＦＮγ５００ｋＵ／Ｌ）和Ｉ２组（ＬＰＡＫ＋ＤＣ＋ＩＦＮγ１００ｋＵ／Ｌ）．每组效靶细胞比分别采用５∶１和１０∶１两种．培养４８ｈ后用中性红比色法检测细胞毒活性．结果Ｌ,Ｄ,Ｔ２和Ｔ１组的细胞毒活性依次增强,各组间差异有显著性（Ｐ＜００１）．Ｇ１和Ｇ２组均高于Ｄ组（Ｐ＜００１）,但Ｇ１,Ｇ２组间差异无显著性．Ｉ１,Ｉ２组与Ｄ组相比,也无显著性差异．随效靶比增加,各组细胞毒活性均相应增强．结论ＤＣ能增强ＬＰＡＫ细胞对肝癌细胞ＢＥＬ７４０２的细胞毒活性;ＴＮＦ或ＧＭＣＳＦ与ＤＣ联用,两者有协同作用;但与ＩＦＮγ联用,则无进一步增强作用     

雷抑素对大鼠移植肝Kupffer细胞的影响

目的探讨肝移植术前应用雷抑素对大鼠肝Ｋｕｐｆｅｒ细胞的影响方法以ＳＤ大鼠为供受体建立原位肝移植模型．受体移植术前３ｄ连续口服１％羧甲基纤维素１ｍｌ／ｄ（对照组）或雷抑素１０ｍｇ／ｋｇ·ｄ（用药组）．分别于术后１，２，３，２４ｈ采血并取肝组织，检测血清ＴＮＦ，ＡＬＴ及肝ＭＤＡ水平，观察肝超微结构及大鼠１周存活率变化．结果对照组移植术后３ｈ血清ＴＮＦ（５３ｋＵ／Ｌ±０４１ｋＵ／Ｌ），肝ＭＤＡ（４８４６ｎｍｏｌ／ｇ±２３６ｎｍｏｌ／ｇ）显著增加，ＴＮＦ表达呈强阳性；而且药组ＴＮＦ（０９ｋＵ／Ｌ±０１１ｋＵ／Ｌ）肝ＭＤＡ（３６１８ｎｍｏｌ／ｇ±１５４ｎｍｏｌ／ｇ）无明显变化，ＴＮＦ表达阴性，两者相差显著Ｐ＜００１）．电镜检查，对照组肝Ｋｕｐｆｅｒ细胞呈活化表现，而用药组肝Ｋｕｐｆｅｒ细胞呈非活化状态．对照及用药组术后１周存活率分别为０％和６０％．结论术前应用雷抑素可抑制移植肝ＴＮＦ和Ｏ２的产生，抑制Ｋｕｐｆｆｅｒ细胞活化，以减轻肝冷缺血再灌注损伤．     

北冬虫夏草多糖对人肿瘤坏死因子α、白细胞介素2及其可溶性受体水平的影响

研究北冬虫夏草多糖对人外周血单个核细胞（ＰＢＭＣ）分泌肿瘤坏死因子α（ＴＮＦ－α），生成可溶性白细胞介素２受体（ｓＩＬ－２Ｒ）及人外周血淋巴细胞（ＰＢＬ）分泌白细胞介素２（ＩＬ－２）的影响。结果表明：北冬虫夏草多糖在１０～５０ｍｇ·Ｌ－１浓度时，刺激单个核细胞分泌ＴＮＦ－α（Ｐ＜０．０５）。在０．１～１０ｍｇ·Ｌ－１浓度时，刺激单个核细胞生成ｓＩＬ－２Ｒ（Ｐ＜０．０５，Ｐ＜０．０１），且在一定浓度范围内ＴＮＦ－α及ｓＩＬ－２Ｒ水平随北冬虫夏草多糖浓度增加而升高；北冬虫夏草多糖对刀豆蛋白Ａ（ＣｏｎＡ）刺激的人外周血淋巴细胞分泌ＩＬ－２水平有明显促进作用（Ｐ＜０．０５）。     

B7转染人肝癌细胞株的建立及生物学特性的实验研究

研究共刺激信号在肿瘤免疫中的作用。脂质体介导DNA转移法将入B7基因转入人肝癌细胞株Smmc7721,建立新的细胞株B7^ Smmc7721,PCR及逆转录PCR（RT-PCR）法鉴定。四唑盐（MTT）比色试验体外检测白细胞介素-2（IL-2）激活的LAK细胞（LAK-C）对两种肝癌细胞的杀伤活性。PCR,RT-PCR法证实B7^ Smmc7721细胞稳定表达B7基因,LAK细胞对B7^ Smmc7721细胞的杀伤活性明显高于Smmc7721,结果有统计学意义。B7基因可以体外转染人肝癌细胞,并表达有活性的B7分子,并可明显增强IL-2激活的LAK细胞的肿瘤杀伤作用,为进一步开展临床应用奠定基础。     

人宫颈癌癌基因-2 促进SMMC 7721细胞分裂和增殖的机制

目的 建立稳定转染含人宫颈癌癌基因(HCCR)-2的SMMC 7721细胞株,探讨HCCR-2对肝癌细胞生物学特性的影响与在SMMC 7721细胞中HCCR蛋白表达的分子信号通路机制. 方法通过脂质体将HCCR-2的真核表达质粒稳定转染至SMMC 7721细胞,Western blot 检测转染后SMMC 7721细胞中HCCR及其下游基因bcl-2蛋白的表达;四甲基偶氮唑盐法检测HCCR-2对转染后SMMC 7721细胞生长的影响;流式细胞仪检测转染后SMMC 7721细胞周期和细胞凋亡率的变化.用不同浓度表皮生长因子(EGF)处理SMMC 7721细胞24 h,以及用LY294002预孵育细胞1 h后用EGF(100 ng/m1)处理SMMC 7721细胞24 h,Western blot检测HCCR的表达变化.建立稳定转染缺陷型Akt质粒(DN-Akt-pcDNA3.1)的SMMC 7721细胞,Western blot 检测总Akt、磷酸化Akt、HCCR及其下游基因bcl-2的表达.数据以均数±标准差(-x±s)表示,进行单因素方差分析.结果 转染HCCR-2的SMMC 7721细胞较转染空载体的SMMC 7721细胞及亲本细胞的HCCR表达升高,HCCR下游基因bcl-2的表达也升高;四甲基偶氮唑盐法显示其增殖能力增强,从72 h开始转染组较空载体组增殖速度加快(P＜0.01);流式细胞仪检测其细胞凋亡率下降(7.72%±0.23%与1.28%±0.16%,P＜0.01),处于分裂周期的细胞比例明显增加(15.76%±0.73%与21.62%±1.33%,P＜0.01).EGF可促进SMMC 7721细胞中HCCR的表达,用LY294002处理细胞后EGF对其HCCR表达的促进作用被抑制.转染DN-Akt-pcDNA3.1的SMMC 7721细胞中HCCR的表达下降,其下游基因bcl-2的表达亦下降.结论 EGF可通过磷脂酰肌醇3激酶/蛋白激酶B信号通路诱导人肝癌细胞SMMC 7721中HCCR蛋白的表达,HCCR可影响人肝癌细胞的细胞周期、凋亡和增殖能力.     

Down-regulation of extracellular signal-regulated kinase 1/2 activity in P-glycoprotein-mediated multidrug resistant hepatocellular carcinoma cells

AIM： To study the expression and phosphorylation of extracellular signal-regulated kinase （ERK） i and ERK2 in multidrug resistant （MDR） hepatocellular carcinoma （HCC） cells.
METHODS： MDR HCC cell lines, HepG2/adriamycin （ADM） and SMMC7721/ADM, were developed by exposing parental cells to stepwise increasing concentrations of ADM. MTT assay was used to determine drug sensitivity. Flow cytometry was employed to analyze cell cycle distribution and measure cell P-glycoprotein （P-gp） and multidrug resistant protein 1 （MRP1） expression levels. ERK1 and ERK2 mRNA expression lev-ls were measured by quantitative real-time PCR （QRTPCR）. Expression and phosphorylation of ERK1 and ERK2 were analyzed by Western blot.
RESULTS： MTT assay showed that HepG2/ADM andSMMC7721/ADM were resistant not only to ADM, but also to multiple anticancer drugs. The P-gp expression was over 10-fold higher in HepG2/ADM cells than in HepG2 cells （8.92% ±0.22% vs 0.88% ± 0.05%, P 〈 0.001） and over 4-fold higher in SMMC7721/ADM cells than in SMMC7721 cells （7.37% ± 0.26% vs 1.74% ± 0.25%, P 〈 0.001）. However, the MRP1 expression was not significantly higher in HepG2/ADM and SMMC7721/ADM cells than in parental cells. In addition, the percentage of MDR HepG2/ADM and SMMC7721/ADM cells was significantly decreased in the G0/G1 phase and increased in the the S phase or G2/M phase. QRT-PCR analysis demonstrated that the ERK1 and ERK2 mRNA expression increased apparently in HepG2/ADM cells and decreased significantly in SMMC7721/ADM cells. Compared with the expression of parental cells, ERK1 and ERK2 protein expressions were markedly decreased in SMMC7721/ADM cells. However, ERK2 protein expression was markedly increased while ERK1 protein expression had no significant change in HepG2/ADM cells. Phosphorylation of ERK1 and ERK2 was markedly decreased in both HepG2/ADM and SMMC7721/ADM MDR cells.
CONCLUSION： ERK1 and ERK2 activities are downregulated in P-gp-mediated MDR HCC cells. ERK1 or ERK2 might be a potential drug target for circumventing MDR HCC cells,     

Effects of cryopreservation and phenylacetate on biological characters of adherent LAK cells from patients with hepatocellular carcinoma

AIM: To improve the preparation of adherent lymphokine-activated killer (A-LAK) cells and to study the effects of cryopreservation and phenylacetate (PA) on biological characters of A-LAK cells. METHODS: A-LAK cells were obtained from peripheral blood mononuclear cells (PBMCs) of the patients with hepatocellular carcinoma (HCC) by using L-phenylalanine methyl ester (PME) to deplete immunosuppressive monocytes. Proliferative activity of SMMC7721 cell line after treatment with phenylacetate (PA) was observed. A-LAK cells were treated with the supernatant of SMMC7721 cells that had been pretreated with PA. The changes of proliferation, cytotoxicity and phenotype of A-LAK cells were investigated after cryopreservation. RESULTS: The expansion of A-LAK cells (96.79 +/- 69.10 folds on Day 14) was significantly higher than that of non-adherent LAK (NA-LAK) cells (22.77 +/- 13.20) as well as conventional LAK cells (4.64 +/- 0.91). PA significantly suppressed the growth of SMMC7721 cells, and the inhibitor ratio was 46%. The supernatant of cultured tumor cells intensively suppressed the proliferation and cytotoxicity of A-LAK cells, but the suppressive effect of the supernatant was previously decreased after treatment with PA. Impairments in proliferation and cytotoxicity of A-LAK cells immediately after thawing of cryopreservation and recovery after reincubation with IL-2 were observed. The cytotoxicity of thawed A-LAK cells on Day 5 was significantly higher than that of fresh A-LAK before freezing (54.8 +/- 10.2% vs 40.5 +/- 6.4%). No significant change in the percentage of lymphocyte subsets was identified in frozen A-LAK cells as compared with that in the fresh control cells. CONCLUSION: A-LAK cells can be simply prepared by using PME, and showed a synergistic anti-tumor effect with the combination of PA. Cryopreservation can increase the immunoactivities of A-LAK cells from the patients with hepatocellular carcinoma.     

HBV宫内感染儿童接种乙型肝炎疫苗免疫失败与IL-2及其受体的关系

目的从ＩＬ－２及其受体角度探讨宫内感染ＨＢＶ导致乙型肝炎（乙肝）疫苗免疫失败的机制。方法采用体外细胞培养、流式细胞仪和酶联免疫检测技术对２２例ＨＢＶ宫内感染儿童和１５例正常儿童的外周血单个核淋巴细胞（ＰＢＭＣ）在非特异性刺激（ＰＨＡ）和特异性刺激（ＨＢｓＡｇ）下的膜ＩＬ－２受体表达水平和ＩＬ－２含量进行了测定。结果在ＨＢｓＡｇ刺激情况下，ＨＢＶ宫内感染儿童接种乙肝疫苗无反应组ＰＢＭＣ的ＩＬ－２膜受体表达水平低于有反应组和正常儿童组。在ＰＨＡ或ＨＢｓＡｇ刺激情况下，ＨＢＶ宫内感染儿童接种乙肝疫苗无反应组ＰＢＭＣ细胞培养上清的ＩＬ－２水平低于有反应组和正常儿童组。结论ＩＬ－２分泌能力低下，以及ＩＬ－２膜受体表达不足可能是宫内感染ＨＢＶ导致乙肝疫苗免疫失败的机制之一。     

人端粒酶催化亚单位锤头状核酶诱导肝癌细胞凋亡的作用

目的 构建带有U6启动子的人端粒酶催化亚单位锤头状核酶真核表达质粒及其突变体,转染入肝癌细胞株SMMC7721,观察端粒酶活性、细胞增殖和凋亡的情况。 方法 用分子克隆技术构建由U6作为启动子、绿色荧光蛋白基因作为报告基因的核酶真核表达质粒pGTRz-U6及其突变体pGTmRz-U6,并以空质粒pEGFP-C1作为对照。Lipofectamine2000转染人肝癌细胞株SMMC7721,G418筛选阳性克隆。RT-PCR检测核酶及hTERT基因的表达,四甲基偶氮唑盐(MTT)作细胞生长曲线观察其生长情况,TRAP-银染法检测端粒酶活性变化,流式细胞计数(FCM)法检测细胞的凋亡水平。 结果 核酶、突变核酶在SMMC7721中持续表达;凝胶成像系统分析SMMC7721-pEGFP-C1、SMMC7721-mRz、SMMC7721-Rz hTERT基因表达,用SPSS10.0软件对3种细胞进行分析,发现三者hTERT基因表达水平不同(F=47.987,P<0.01);t检验分析得出SMMC7721-Rz hTERT基因表达明显低于SMMC7721-mRz和SMMC7721- pEGFP-C1(t值分别为-7.640和-11.602,P值均<0.01)。SMMC7721-pEGFP-C1和SMMC7721-mRz hTERT表达没有区别(t=-0.178,P>0.05)。TRAP-银染及FCM结果分别显示,随着细胞的分裂,SMMC7721-Rz和SMMC7721-mRz细胞端粒酶活性逐渐降低,凋亡水平逐渐增加,7PDS细胞凋亡率分别是29.86％和9.87％,而对照组SMMC     

肿瘤坏死因子相关凋亡诱导配体基因对肝癌细胞杀伤作用及旁观者效应研究

目的 探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)基因在诱导肝癌细胞凋亡时是否存在旁观者效应，以及旁观者效应的可能机制。方法 构建表达TRAIL基因的双腺病毒载体系统Ad／GT-TRAIL Ad／PGK-GV16，通过293包装细胞产生的病毒上清液将TRAIL基因转入肝癌细胞SMMC7721细胞中，RT-PCR检测TRAIL基因的表达，以MTT法检测细胞生长抑制率，流式细胞仪检测细胞凋亡率；不同比例混合培养SMMC7721／TRAIL和SMMC7721细胞，检测混合细胞生长抑制率来评价TRAIL基因的旁观者效应，并以滤去细胞成分的转染细胞培养液培养未转染细胞，观测可溶性因子在TRAIL基因旁观者效应中的作用。结果 TRAIL基因对SMMC7721细胞的生长抑制率与PBS、LacZ基因和Bax基因比较，差异有显著性(P＜0．05)；SMMC7721细胞的凋亡率，TRAIL基因与PBS、LacZ基因和Bax基因比较，差异有显著性(P＜0．05)；混合细胞的生长抑制率，以SMMC7721／TRAIL占0％时为0，占5％时为15．9％，占25％时为67．0％，占50％时为80．2％，占100％时为87．7％；以PBS对SMMC7721的生长抑制率为0，则滤去细胞成分的转染细胞培养液对SMMC7721的生长抑制率为4％，两者差异无显著性。结论 双腺病毒载体系统介导的TRAIL基因对肝癌细胞有明显的抑制生长和促凋亡作用，并存在旁观者效应，可溶性因子在TRAIL的旁观者效应中不起作用。     

Cytokine activity after human bone marrow transplantation III. DEFECT IN IL2 PRODUCTION BY PERIPHERAL BLOOD MONONUCLEAR CELLS IS NOT CORRECTED BY STIMULATION WITH Ca++ IONOPHORE PLUS PHORBOL ESTER

Previous studies have shown that interleukin 2 (IL2) production by peripheral blood mononuclear cells (PBMC) is severely impaired post allogeneic bone marrow transplantation, whereas production of interferon-gamma (IFN-gamma) is at most marginally depressed. To investigate the mechanisms behind this apparently differential inhibition of lymphokine production, we stimulated PBMC from recipients of HLA-identical sibling bone marrow transplants with phytohaemagglutinin (PHA), PHA + phorbol ester (PMA) (to bypass accessory cell requirements) or Ca++ ionophore + PMA (to bypass both accessory cell and T cell surface receptor (CD2 and/or CD3/Ti interactions). Increasing the potency of the stimulus increased the amount of IL2 and IFN produced by PBMC from both normal volunteers and from marrow transplant recipients, but for each stimulus the amount of IL2 produced by marrow transplant recipient PBMC remained 10-100-fold lower than that produced by normal PBMC, suggesting an underlying defect in IL2 production by marrow transplant recipient T cells, not due to accessory cell or CD2 defects. Selection experiments showed that CD3+ cells were the primary IL2 producers, and we were unable to demonstrate presence of suppressor cells in marrow transplant PBMC. Statistical analysis of the clinical factors possibly affecting lymphokine synthesis showed that in vivo cyclosporin A did not affect the in vitro capacity of PBMC to produce cytokines, although steroid therapy had a negative effect on IL2 production. The only variable significantly affecting IL2 and IFN production in marrow transplant recipients was increasing time post transplant. It is suggested that the defect in IL2 but not IFN production could be due to either a selective reduction in the frequency of IL2 producing cells as opposed to IFN producing cells, or to a reduction in the amount of IL2 produced per cell in marrow transplant recipients.     

Resistance of some leukemic blasts to lysis by lymphokine activated killer (LAK) cells

Peripheral blood mononuclear cells (PBMC) from healthy donors and AML patients in remission were stimulated with phytohemagglutinin (PHA) and recombinant interleukin-2 (IL-2). These stimulated cells (lymphokine activated killer (LAK) cells) showed increased DNA synthesis as measured by 3H-Thymidine uptake. A synergistic effect of PHA and IL-2 was found. LAK cells' ability to kill acute myeloid leukemia (AML) blasts was investigated by the 51Cr release assay. LAK cells showed a cytotoxicity (over 10% specific 51Cr release) against 9/12 leukemic blasts, even at effector/target (E/T) ratios as low as 5:1. However, on average only 22.2% (SD 11.8) and 36.5% (SD 12.5) 51Cr release were obtained in 4- and 18-hour cytotoxicity assays, respectively, at an E/T ratio of 20:1. Leukemic blasts in 3/12 AML cases and normal PBMC were entirely resistant to lysis, even at an E/T ratio of 80:1. Susceptibility to lysis was not correlated to peanut-agglutinin receptor expression. LAK cells were more cytotoxic towards the K-562 cell line (natural killer activity) than unstimulated PBMC.     

Sequential expression of protooncogenes during lectin-stimulated mitogenesis of normal human lymphocytes.

The proliferation of non-neoplastic T lymphocytes is regulated, in part, by the coordinated expression of genes encoding T-cell growth factor (interleukin 2, IL2), IL2 receptors (IL2R), and transferrin receptors (TFR). In addition to growth factors and their receptors, protooncogenes may regulate lymphocyte proliferation. We used cloned cDNAs homologous to 21 different protooncogenes to screen for their expression at the mRNA level in human peripheral blood mononuclear cells (PBMC) stimulated with the mitogenic lectin phytohemagglutinin (PHA), and we compared the time course of accumulation of mRNAs for these protooncogenes to that of mRNAs for the IL2, IL2R, TFR, and histone H3 genes. mRNAs for c-abl, c-ets, c-yes, and N-ras were present in unstimulated PBMC. After stimulation of PBMC by PHA, we detected marked increases within 10 min in the levels of mRNA for c-fos and c-myc; within 6 hr for IL2 and IL2R mRNAs; within 14 hr for c-myb, p53, N-ras, and TFR mRNAs; and within 24-36 hr for H3 mRNA. Expression of c-abl, c-ets, and c-yes increased gradually following stimulation with PHA. None of the other protooncogenes tested was expressed in PBMC. Addition of the protein synthesis inhibitor cycloheximide, before the addition of PHA to cultures, abolished the PHA-induced accumulation of mRNAs for c-myb, N-ras, and TFR, but not of mRNAs for c-fos, c-myc, IL2, and IL2R. These data indicate that c-fos, c-myc, IL2, and IL2R belong to a group of genes expressed early, whereas c-myb, N-ras, and TFR belong to a group of genes expressed later in PHA-activated PBMC, and that the products of the c-fos and c-myc protooncogenes are not required for expression of IL2 or IL2R genes. Addition of purified IL2 augmented the expression of the later-expressed genes c-myb, p53, N-ras, and TFR in PHA-stimulated cultures of PBMC, as well as of the early genes c-myc and IL2R, but not of c-fos and IL2, thus suggesting that PHA and IL2 stimulate the expression of overlapping, but nonidentical, sets of genes in PBMC.