B7-H4及Fas、FasL与宫颈癌免疫逃逸机制的关系

目的:检测免疫共刺激分子B7-H4及Fas、FasL在不同宫颈组织中的表达，研究三者的异常表达与宫颈癌免疫逃逸机制的关系。方法:选择陕西省肿瘤医院病理科2014-2018年的石蜡包埋标本162例，采用免疫组织化学方法检测20例正常宫颈、30例宫颈上皮内瘤变(CIN)和112例I期-IV期宫颈癌组织中B7-H4及Fas、FasL的表达水平。结果:B7-H4在正常宫颈组、CIN组、宫颈癌组的阳性表达率分别为0、20.0%、47.32%，两两相比，具有显著性差异（P<0.05）。在112例宫颈癌病例中FIGO临床分期I期至IV期各期别宫颈癌组织B7-H4的阳表达率分别为16.67%、43.18%、70.83%、85.71%，各组间相比差异具有统计学意义。正常对照组Fas的阳性表达率是85.00％，CIN组43.33％，宫颈癌组41.96％，正常组与CIN、正常组与宫颈癌组相比差异均具有统计学意义（P<0.05），CIN组与宫颈癌组相比，无明显差异（P>0.05）。FasL的阳性表达率在正常组为20.00%，CIN组为50.00%，宫颈癌组为56.25%，正常组与CIN、宫颈癌组比较，差异具有统计学意义(P<0.05)，CIN组与宫颈癌组比较无显著差异;B7-H4阳性宫颈癌组Fas阳性表达率28.30%明显较B7-H4阴性宫颈癌组Fas阳性表达率54.24%低，差异具有统计学意义（P<0.05）；而B7-H4阳性宫颈癌组FasL阳性表达率79.25%明显高于B7-H4阴性宫颈癌组FasL阳性表达率35.59%，差异具有统计学意义（P<0.05）。结论:负性免疫共刺激分子B7-H4和Fas、FasL凋亡蛋白在宫颈癌的发生、进展中起到了重要作用，其协同作用可能为宫颈癌细胞逃逸机体免疫的机制之一。     

Responsiveness to i.v. immunoglobulin therapy in patients with toxic epidermal necrolysis: A novel pharmaco-immunogenetic concept

Toxic epidermal necrolysis (TEN) represents a rare drug-induced autoimmune reaction with delayed-type hypersensitivity that initiates the process of developing massive keratinocyte apoptosis, dominantly in the dermoepidermal junction. Although the etiopathophysiology has not yet been fully elucidated, the binding of Fas ligand (FasL, CD95L) to the Fas receptor (CD95) was shown to play a key role in the induction of apoptosis in this syndrome. The knowledge of the role of immunoglobulin G (IgG) in inhibition of Fas-mediated apoptosis contributed to the introduction of i.v. Ig (IVIg) in the therapy of TEN patients. Despite great enthusiasm for this therapy at the end of the 1990s, subsequent studies in various populations and meta-analyses could not unequivocally confirm the efficacy of the IVIg-based treatment concept. Today, therefore, we are faced with the dilemmas of how to adjust therapy of TEN patients most effectively, which patients could benefit from IVIg therapy and what dose of the preparation should be administrated. The ground-breaking question is: do the host genetic profiles influence the responsiveness and side-effects of IVIg therapy in TEN patients? Based on recent pharmacological, immunological and genetic findings, we suggest that the variability of IVIg therapy outcomes in TEN patients may be related to functional variants in Fas, FasL and Fc-γ receptor genes. This novel concept could lead to improved quality of care for patients with TEN, facilitating personalized therapy to reduce mortality.     

Mechanism of Fas-mediated cell death and its enhancement by TNF-alpha in human salivary gland adenocarcinoma cell line HSG

Fas-mediated cell death in a human salivary gland adenocarcinoma cell line (HSG) was induced by treatment of the cells with agonistic anti-Fas antibody (CH-11), and this cell death was enhanced by pretreatment with tumor necrosis factor alpha (TNF-alpha). The mode of cell death was apoptosis, because it was accompanied by caspase activation and the cleavage of poly(ADP-ribose) polymerase. The TNF-alpha treatment of the cells increased the expression of Fas, which was accompanied by the activation of nuclear factor kappaB (NFkappaB). These results suggest that the enhancement of the apoptosis caused by TNF-alpha resulted from increased sensitivity of the HSG cells to CH-11-mediated apoptosis due to induction of Fas protein by TNF-alpha via the activation of NFkappaB. In order to elucidate the apoptosis signaling pathway, we examined the effect of various caspase inhibitors on the apoptosis induced by CH-11. Fas-mediated apoptosis of HSG cells was slightly inhibited by the caspase-9 inhibitor although it was mainly inhibited by that for caspase-8. Based on this finding, we consider CH-11-induced apoptosis in HSG cells to be mainly mediated by the type I death signaling pathway that is caused by a caspase cascade initiated by the activation of caspase-8 at the death-inducing signaling complex (DISC).     

维生素E琥珀酸酯诱导舌鳞癌Tca8113细胞凋亡的研究

目的探讨维生素E琥珀酸酯（VES）对人舌鳞癌Tca8113细胞的凋亡诱导作用及其可能的分子机制。方法四甲基偶氮唑蓝（MTT）检测VES对舌鳞癌Tca8113细胞的抑制作用；应用流式细胞仪分析不同质量浓度VES处理后舌鳞癌细胞的凋亡率；Fas中和抗体进行阻断实验；以细胞免疫化学法和流式细胞仪检测VES处理后肿瘤细胞Fas蛋白水平和细胞表面Fas表达的变化。结果不同质量浓度的VES处理后，舌鳞癌细胞的生长受到明显的抑制，肿瘤细胞的凋亡率显著上升，呈现时间依赖性和剂量依赖性；Fas中和抗体进行阻断后，细胞凋亡率显著下降；VES处理后细胞Fas蛋白表达增强；流式细胞仪检测细胞表面Fas平均荧光强度也显著升高。结论VES对舌鳞癌细胞具有凋亡诱导作用，其作用机制与肿瘤细胞表面Fas蛋白表达的上调有关。     

口腔鳞状细胞癌Fas基因表达与细胞凋亡关系的研究

目的　探讨Fas基因mRNA及蛋白表达水平与人口腔鳞状细胞癌细胞凋亡的关系。方法　应用Northern 杂交、双参数流式术(TUNEL法)检测人口腔鳞状细胞癌中Fas mRNA及蛋白的表达,鳞癌细胞的细胞周期与凋亡水平。结果　5例正常口腔黏膜标本中均有Fas mRNA及蛋白的表达。在口腔鳞癌组织中,Fas mRNA及蛋白的表达与口腔鳞癌组织病理学分级有关(P<0·005),与口腔鳞癌组织分化程度和凋亡指数呈正相关。结论　口腔鳞癌中 Fas基因的表达与组织病理学分级及细胞凋亡之间关系密切。     

口腔鳞癌患者手术前后血清可溶性Fas的变化

目的 研究可溶性Fas在口腔鳞癌患者手术前后血清中的浓度变化.方法 选择口腔鳞癌患者25例为鳞癌组,健康志愿者11例为对照组.采用双抗体夹心ELISA法检测口腔鳞癌患者术前和术后第7天以及对照组健康者血清中可溶性Fas的浓度.结果 血清中可溶性Fas的浓度鳞癌组术前为(8.20±1.17) ng/L、术后为(6.45±1.23) ng/L,对照组为(5.62±1.22) ng/L.鳞癌组术前可溶性Fas浓度高于对照组,差异有统计学意义(P＜0.05);鳞癌组手术前后可溶性Fas浓度差异有统计学意义(P＜0.05).结论 血清可溶性Fas水平测定对估计口腔癌的病情变化可能有一定的临床意义.     

Fas转染及抗体处理对舌鳞癌细胞Tca8113移植瘤形成和增殖的影响

目的　研究Fas转染和抗Fas单克隆抗体对舌鳞癌细胞系Tca8113裸鼠体内移植瘤形成和增殖的影响,探讨相关机制。方法　脂质体法以真核表达重组质粒pBK-fas转染舌鳞癌细胞系Tca8113。部分转染细胞行抗Fas单克隆抗体处理。未转染细胞、Fas转染细胞、Fas转染抗体处理细胞分别接种裸鼠皮下。观测移植瘤生长,绘制生长曲线。RT-PCR检测肿瘤细胞Fas mRNA表达。流式细胞术(FCM)检测肿瘤细胞凋亡、增殖及Fas蛋白表达。结果　Fas转染和抗体处理延迟肿瘤形成,抑制肿瘤增殖。Fas转染上调移植瘤Fas mRNA表达,提高Fas蛋白表达强度和凋亡指数,但不影响Fas蛋白阳性表达率和增殖指数。抗体处理不影响Fas mRNA和蛋白表达,但可提高凋亡指数,降低增殖指数。结论　Fas转染抑瘤效应是上调Fas转录和表达、促进凋亡的结果。抗Fas单克隆抗体抑瘤效应则与激活凋亡和抑制增殖有关。     

Bcl-2、Bax、Fas在大肠癌脾胃虚弱证患者舌苔脱落细胞表达及其相关性研究

目的：探讨舌苔脱落细胞凋亡相关蛋白Bcl-2、Bax、Fas表达水平与大肠癌脾胃虚弱证的关联性。方法：用免疫组化方法,检测舌苔脱落细胞凋亡相关蛋白Bcl-2、Bax、Fas的阳性表达率。结果：三组间Bcl-2、Bax蛋白阳性表达率有统计学意义,P＜0.05;Fas蛋白阳性表达率无统计学意义,P＞0.05。结论：Bcl-2蛋白高表达,抑制细胞凋亡,Bax蛋白低表达,使细胞凋亡能力减弱,共同作用使舌苔细胞的生存期延长,细胞凋亡速率减慢,这可能是导致肿瘤细胞增殖与凋亡失衡,引发细胞恶性增殖而发为癌症的主要原因。     

Transgenic expression of decoy receptor 3 protects islets from spontaneous and chemical-induced autoimmune destruction in nonobese diabetic mice

Decoy receptor 3 (DCR3) halts both Fas ligand- and LIGHT-induced cell deaths, which are required for pancreatic beta cell damage in autoimmune diabetes. To directly investigate the therapeutic potential of DCR3 in preventing this disease, we generated transgenic nonobese diabetic mice, which overexpressed DCR3 in beta cells. Transgenic DCR3 protected mice from autoimmune and cyclophosphamide-induced diabetes in a dose-dependent manner and significantly reduced the severity of insulitis. Local expression of the transgene did not alter the diabetogenic properties of systemic lymphocytes or the development of T helper 1 or T regulatory cells. The transgenic islets had a higher transplantation success rate and survived for longer than wild-type islets. We have demonstrated for the first time that the immune-evasion function of DCR3 inhibits autoimmunity and that genetic manipulation of grafts may improve the success and survival of islet transplants.