组织因子途径抑制物基因转移对大鼠血管平滑肌细胞凋亡的影响

目的 研究组织因子途径抑制物(TFPI)基因转移对大鼠血管平滑肌细胞(VSMC)凋亡的影响,探讨其抑制血管成形术后再狭窄的机制.方法 在体外培养的大鼠VSMC中分别转染含有人TFPI基因的重组腺病毒(Ad-TFPI)、含β-半乳糖苷酶基因的重组腺病毒(Ad-LacZ)或PBS.通过RT-PCR方法检测外源TFPI基因的表达.细胞计数和MTT法测定细胞生长情况.电镜技术、流式细胞仪和TUNEL法分别检测细胞凋亡情况.结果 基因转移后3 d在VSMC中检测到TFPI mRNA的表达.细胞计数结果显示第1、3、5天各组细胞数无明显差异,而第7天Ad-TFPI组细胞数明显少于Ad-LacZ组和PBS组(P＜0.05).MTT结果显示基因转移后第1、3、5天各组细胞的吸光度值比较差异无统计学意义,而第7天Ad-TFPI组的吸光度值明显低于Ad-LacZ组(P＜0.05)和PBS组(P＜0.01).流式细胞仪检测结果显示基因转移后3、5、7 d Ad-TFPI组细胞早期凋亡结果均高于Ad-LacZ组.基因转移后3 d和7 d,Ad-TFPI组TUNEL阳性率分别为(10.82±1.57)%和(16.95±2.01)%,明显高于Ad-LacZ组(3.46±0.93)%和(5.11±1.29)%(P＜0.05).透射电镜结果显示基因转移后3、5、7 d Ad-TFPI组细胞逐渐出现体积变小、线粒体轻度肿胀、核固缩以及凋亡小体形成,而Ad-LacZ组则无明显改变.结论 TFPI基因转移能够显著诱导体外培养的大鼠VSMC发生凋亡,可能是其抑制血管成形术后再狭窄的机制之一.     

人组织因子途径抑制物基因在兔颈动脉损伤血栓形成中的作用

目的 观察人组织因子途径抑制物(tissue factor pathway inhibitor,TFPI)基因在兔颁动脉损伤血栓形成的作用.方法 大耳白兔40只,体质量2.5～3.0 kg.将白兔按体质量随机分为4组:腺病毒介导的TFPI基因(Ad-TFPI)转染组、腺病毒介导的LacZ基因(Ad-LzcZ)转染组、磷酸盐缓冲液(PBS)组和对照组,每组10只.对照组不进行任何处理,另3组用PTCA球囊导管对白兔右侧颈动脉进行损伤,损伤处分别用DisDatch转基因导管按组别局部注射转染Ad-TFPI、Ad-LacZ液和PBS各0.2 ml.转染10 d后,采用相同方法对白兔颈动脉损伤处进行二次损伤,对照组进行第1次损伤,损伤后立即恢复血流.30 min后处死白兔,分别取出损伤侧和对侧颈总动脉,沿长轴剪开、展平,2%戊二醛固定,扫描电镜下观察4组白兔损伤处动脉管壁血小板聚集及纤维素(血栓)形成情况.结果 扫描电镜下,正常未经任何损伤的颈动脉管腔内可见血管内皮细胞结构完整,排列整齐;对照组在球囊损伤后血管内皮不完整,有部分血小板聚集,血管肇上无纤维素生成;Ad-TFPI组在二次损伤后血小板聚集增加,但血管壁上未见纤维素形成;Ad-LacZ组和PBS组可见皿管壁上有大量的纤维素形成和红细胞堆积.血管壁血栓形成阳性率组间比较差异有统计学意义(χ2=14.95,P<0.01);其中Ad-TFPI组(20%)低于Ad-LacZ组(80%,χ2=7.20,P<0.01)和PBS组(70%,χ2=5.05,P<0.05),高于对照组(10%,χ2=0.39,P>0.05);Ad-LacZ组(80%)高于对照组(10%,χ2=9.90,P<0.01),也高于PBS组(70%,χ2=0.27,P>0.05);PBS组(70%,)高于对照组(10%,χ2=7.50,P<0.01).结论 二次球囊损伤法可造成大量血栓形成;腺病毒表达载体TFPI可以抑制动脉损伤后纤维素沉积.     

融原型病毒脂质体载体与阻塞性血管疾病的基因治疗

为改善脂质体作为基因治疗的工具所介导的ＤＮＡ转移效率，基于病毒细胞融合原理，研制了融原型病毒脂质体载体日本血凝病毒融合蛋白与包囊寡脱氧核苷酸或质粒ＤＮＡ的脂质体组成的复合物。该脂质体与质膜的融合将ＤＮＡ直接导入胞浆。将一种ＤＮＡ结合核蛋白渗入该脂质体可增强质粒转基因的表达。可将长达１００ｋｂ的完整基因导入体内细胞。目前已成功地用于血管增殖性疾病细胞静止基因治疗模型中。类似的策略可望用于静脉移植物遗传工程以及免疫介导的小鼠肾小球疾病模型的治疗。     

构建高表达组织型纤溶酶原激活物基因质粒预防兔动脉粥样硬化血栓形成

目的探讨组织型纤溶酶原激活物基因质粒在预防动脉粥样硬化及血栓形成中的作用。方法新西兰纯种兔20只,分为基因治疗组和模型组,每组各10只,基因治疗组双侧髂动脉内膜剥脱术 转基因治疗 高胆固醇饮食喂养;模型组双侧髂动脉内膜剥脱术 高胆固醇饮食喂养。4周后处死动物,观察动脉内粥样硬化病变和血栓形成;在处死动物的同时抽血检测D-二聚体含量。结果成功建立了兔髂动脉粥样硬化模型并获得了组织型纤溶酶原激活物在血管周围肌肉组织中的有效表达。构建的组织型纤溶酶原激活物基因质粒可显著抑制兔动脉血管损伤后平滑肌细胞增殖细胞核抗原表达(13.55±8.43比27.78±12.35)和血小板源生长因子BmRNA表达(3.54±1.78比20.40±11.25),显著减少血管内膜厚度(32.75±21.50μm比165.70±71.21μm)和内膜面积(0.41±0.47mm2比2.01±1.15mm2),且显著抑制了局部血管粥样硬化病变发展并使病变血管内血栓形成明显减少。结论构建的组织型纤溶酶原激活物基因质粒可用于预防兔实验性动脉粥样硬化血栓形成。     

TFPI基因转染对血管平滑肌细胞中细胞凋亡抑制蛋白的调控

目的研究组织因子途径抑制物(TFPI)基因转染对大鼠血管平滑肌细胞中细胞凋亡抑制蛋白(IAP)表达的影响,探讨TFPI诱导细胞凋亡的可能机制。方法将含有人TFPI基因的重组腺病毒或含β-半乳糖苷酶(LacZ)基因的重组腺病毒或DMEM在体外分别转染大鼠血管平滑肌细胞,用ELISA方法测定转染后细胞中TFPI蛋白的表达水平,用RT-PCR方法测定基因转染后不同时间点细胞中c-IAP1mRNA的表达,用Western-blot方法检测基因转染后不同时间点细胞中survivin的表达。结果基因转染后1天在血管平滑肌细胞中即可检测到TFPI蛋白表达,峰值出现在转染后第3天;基因转染后3天和7天,TFPI组c-IAP1 mRNA的表达与对照组相比明显减少(P0.05);基因转染后3、5、7天,TFPI组survivin的表达与对照组相比明显减少(P0.05),且具有明显的时间依赖性。结论 TFPI可能通过抑制IAP的表达来发挥诱导平滑肌细胞凋亡的作用,从而抑制冠状动脉介入治疗后再狭窄发生。     

腺病毒介导组织因子途径抑制物基因转染兔损伤颈动脉后的表达及对内膜增生的抑制作用

目的 检测人组织因子途径抑制物(tissue factor pathway inhibitor,TFPI)基因腺病毒载体系统在体表达及对兔颈动脉球囊损伤后新生内膜增生的抑制作用.方法 共采用中国大耳白兔70只.分为4组,分别为腺病毒介导TFPI基因(Ad-TFPI)转染组、腺病毒介导LacZ基因(Ad-LacZ)转染组、PBS组及假手术组,前3组分别于颈动脉球囊损伤后局部转染Ad-TFPI、Ad-LacZ或PBS,假手术组只分离颈总动脉,不做球囊损伤.Ad-TFPI组和Ad-LacZ组每组25只动物,PBS组及假手术组每组10只.Ad-TFPI组和Ad-LacZ组分别于术后3、7、10、14和28 d各处死3只动物,用RT-PCR、ELISA方法 ,检测TFPI在颈动脉壁中的表达.术后4周时,4组剩余动物(每组10只)行颈动脉造影检测最小管腔直径,之后取血管标本,观察病理形态学变化,测算出血管新生内膜面积、内膜与中膜的比例(I/ M)、管腔狭窄程度.结果 基因转染后3 d,Ad-TFPI 组检测到TFPI mRNA及蛋白表达,10～14 d为表达高峰,28 d有所下降但仍可检测到,Ad-LacZ组未测到人TFPI的表达.基因转染后4周,颈动脉造影结果 示Ad-TFPI组最小管腔直径明显大于PBS组和Ad-LacZ组[(1.17±0.43)mm比(0.43±0.33)mm、(0.39±0.24)mm],管腔狭窄百分率明显低于PBS组和Ad-LacZ组[(32±8.2)%比(79±10.2)%、(81±13.1)%],P均<0.01.形态学检查分析结果 显示Ad-TFPI组新生内膜面积明显小于PBS组和LacZ组[(0.17±0.03)mm2比(0.73±0.03)mm2、(0.78±0.04)mm2],L/ M值明显小于PBS组和LacZ组(1.02±0.25比2.76±0.33、2.92±0.24),管腔狭窄程度明显低于PBS组和LacZ组[(24.5±2.1)%比(78.2±2.8)%、(81.3±3.2)%],P均<0.01.结论 人TFPI腺病毒表达载体可在体内有效表达,并且对血管成形术后再狭窄有抑制作用.     

尼古丁对血管内血栓形成的影响

目的 研究不同条件尼古丁介导的人脐静脉内皮细胞(HUVECs)表达组织因子途径抑制物-2(TFPI -2)的影响.方法 选用第4代～6代HUVECs,接种于24孔培养板中,随机分为5组.实验组分别于培养液中加入不同体积的尼古丁,使其终浓度分别为0.1 μmol/L、1 μmol/L、10 μmol/L及100μmol/L;对照组以相同体积的PBS液代替尼古丁同步培养,孵育12 h后收集各组细胞的上清液,采用酶联免疫吸附双抗体夹心分析(ELISA)法测定各组上清液中TFPI -2的含量.结果 10 μmol/L、100 μmol/L尼古丁组TFPI -2蛋白表达较对照组明显减少,差异有统计学意义(P＜0.05);0.1 μmol/L、1 μmol/L尼古丁组TFPI -2蛋白表达与对照组比较,差异无统计学意义(P＞0.05); 100 μmol/L尼古丁组较10 μmol/L尼古丁组TFPI -2蛋白表达减少,差异有统计学意义(P＜0.05).结论 尼古丁可以损伤血管内皮细胞,引起TFPI -2蛋白表达降低,影响其凝血功能,从而增加血栓的发生几率.     

各类型肝炎及失代偿期肝硬化患者血浆中组织因子途径抑制物测定的临床意义

目的:测定各类型肝炎及失代偿期肝硬化患者血浆中的组织因子途径抑制物(Tissue factor pathway in-hibitor,TFPI),并探索其临床意义。方法:TFPI抗原(TFPI:Ag)测定采用双夹心ELISA抗原测定法,TFPI活性(TFPI:A)测定采用发色底物法。结果:急性中毒性肝炎(n=14)TFPI:Ag为160.3±26.1ng/ml,TFPI:A为515.8±50.2 u/ml;急性病毒性肝炎(n=20)各为197.7±18.6 ng/ml与532.1±98.7 u/ml;慢性乙型肝炎(n=48)各为162.5±28.3ng/ml与636.7±54.8 u/ml;失代偿期肝硬化(n=20)各为81.7±16.7 ng/ml与747.2±81.2u/ml。与对照组相比,TF-PI:Ag(正常值103.2±11.5 ng/ml)除肝硬化组接近正常低值外,其它各组均有增高(P<0.05);TFPI:A(正常值112.5±23.6 u/ml)各组均增高(P<0.01)。结论:炎症时因单核-巨噬细胞活跃及炎症因子刺激血管内皮细胞,故使TFPI过度表达,但在肝硬化时TFPI:Ag已趋向正常低值,可能与门静脉系血栓形成过程中TFPI不断大量消耗有关。     

组织因子途径抑制物基因对支架内再狭窄的抑制作用

目的探讨腺病毒介导的人组织因子途径抑制物基因转移抑制兔髂股动脉支架内再狭窄的有效性、安全性及相关机制。方法对36只新西兰白兔进行双侧髂股动脉球囊损伤,然后植入镍钛合金自膨胀支架,再分别局部灌注保留腺病毒介导的人组织因子途径抑制物基因、细菌β半乳糖苷酶基因和生理盐水。术后第3、7、28天分别取各组实验血管段,用X-Gal染色观察外源基因的转染效率,逆转录聚合酶链反应检测组织因子途径抑制物基因mRNA的表达,免疫组织化学染色检测血管壁细胞增殖细胞核抗原的表达情况,细胞凋亡原位检测法确定血管壁细胞的凋亡情况,组织形态学观察研究管腔的狭窄程度,血液生物化学及组织形态学评价基因治疗的安全性。结果外源组织因子途径抑制物基因成功转染至血管壁细胞并表达成mRNA;组织因子途径抑制物可抑制平滑肌细胞的增殖(P<0.05)、促进其凋亡(P<0.05),抑制支架内再狭窄形成(P<0.05),各组动物重要脏器无病理学改变。结论组织因子途径抑制物基因有效抑制了兔髂动脉支架内再狭窄的形成且无明显毒副作用,其机制与抑制平滑肌细胞增殖及促进其凋亡有关。     

人组织因子途径抑制物腺病毒表达系统的构建及体内表达

目的构建携载人组织因子途径抑制物(tissuefactorpathwayinhibitor,TFPI)基因的重组腺病毒载体,为基因治疗提供实验基础。方法利用基因重组技术,将人TFPI基因连接到穿梭质粒pDC316中,然后将腺病毒骨架质粒pBHGlox△E1,3Cre以及重组穿梭质粒pDC316-TFPI共转染293细胞,并在其中发生Cre重组酶介导的位点,特异性重组及腺病毒包装,扩增后进行滴度测定。将包装成功的携带人TFPI基因的重组腺病毒(Ad-TFPI)转染兔颈动脉,并用携带LacZ报告基因的重组腺病毒(Ad-LacZ)作为对照,3d后RT-PCR、ELISA法检测人TFPImRNA、蛋白的表达。结果得到了携带人TFPI基因的重组腺病毒,包装的病毒蚀斑形成单位(plaqueformationunit,PFU)滴度为7.6×1012/L。在Ad-TFPI转染兔颈动脉后3d,RT-PCR法和ELISA法均检测出TFPI表达,Ad-LacZ转染后未测到人TFPI的表达。结论成功构建了人TFPI腺病毒表达载体,为下一步的基因治疗提供了基础。     

Tissue factor pathway inhibitor gene delivery using HVJ-AVE liposomes markedly reduces restenosis in atherosclerotic arteries

OBJECTIVE: Tissue factor pathway inhibitor (TFPI), as a primary inhibitor of TF-induced coagulation, reduces neointimal formation and luminal stenosis by inhibiting coagulation and thrombosis after vessel wall injury. Here, we investigated the effect of TFPI gene delivery with a HVJ-AVE liposome vector on restenosis in atherosclerotic arteries after angioplasty in rabbits. We also evaluated the safety of the novel gene therapeutic strategy to prevent restenosis. METHODS: Local iliac artery atherosclerosis was induced by a combination of balloon denudation and high-cholesterol diet in Japanese white rabbits, which were then subjected to angioplasty. Infusion of an HVJ-AVE liposome containing the TFPI gene or an "empty" pcDNA 3.1 expression vector, or HVJ-liposome vector only, or saline was performed at the site of angioplasty using a Dispatch((R)) catheter. Quantitative angiography and histopathology were performed before and after gene delivery and at 4 weeks follow-up. The safety of the gene therapy was evaluated over a 6-month observation period. RESULTS: TFPI mRNA and protein were detected in local TFPI gene transferred vessels after gene transfer. The mean minimal luminal diameter of the TFPI group was markedly greater than that of the control groups (P<0.01) at 4 weeks after gene transfer. The mean neointimal area, the ratio of the neointimal to medial areas, and percent of stenosis in the TFPI group were all significantly reduced compared with the control groups (each P<0.01). The external elastic luminal area, internal elastic luminal area, and luminal area were larger in the TFPI groups versus controls (each P<0.01). Thrombosis was found in five empty plasmid control group animals, but in only one in the TFPI group (P=0.05). The systemic coagulation status of the treated animals were not significantly changed in either the TFPI group or the control groups; no toxicity was observed after HVJ-AVE liposome-mediated TFPI gene transfer. CONCLUSIONS: HVJ-AVE liposome-mediated TFPI gene transfer significantly reduced neointimal hyperplasia, inhibited thrombosis, and attenuated vascular remodeling and lumimal stenosis after angioplasty in atherosclerotic arteries without any significant adverse effects.     

Adenovirus-mediated local expression of human tissue factor pathway inhibitor eliminates shear stress-induced recurrent thrombosis in the injured carotid artery of the rabbit.

The main cause of acute coronary syndrome may be recurrent thrombosis, which is initiated by the activation of the extrinsic coagulation pathway. Tissue factor (TF) pathway inhibitor (TFPI) efficiently inhibits an early step in this pathway by the formation of a complex with factor VIIa, TF, and factor Xa. We determined whether local TFPI gene transfer can inhibit thrombosis in an injured artery without inducing systemic side effects. Balloon-injured rabbit carotid arteries were infected with an adenoviral vector that expressed either human TFPI (AdCATFPI) or bacterial beta-galactosidase (AdCALacZ). Two to 6 days after gene transfer, thrombosis was induced by the production of constant stenosis of the artery, and blood flow was measured continuously with an electromagnetic flow probe. A cyclic flow variation, which is thought to reflect the recurrent formation and dislodgment of mural thrombi, was observed in all AdCALacZ-infected arteries as well as in saline-infused arteries. In contrast, no cyclic flow variation was detectable in AdCATFPI-transfected arteries, even in the presence of epinephrine (1 microg. kg-1. min-1 infusion). Prothrombin time, activated partial thromboplastin time, and the ex vivo platelet aggregation induced by either adenosine diphosphate or collagen were unaltered in AdCATFPI-infected rabbits. We found that in vivo TFPI gene transfer into an injured artery completely inhibits the recurrent thrombosis induced by shear stress even in the presence of catecholamine, without affecting systemic coagulation status. Adenovirus-mediated local expression of TFPI may have the potential for the treatment of human thrombosis.     

Development of novel method of non-viral efficient gene transfer into neonatal cardiac myocytes

To establish new treatment for cardiovascular disease, the development of safe and highly efficient vectors is necessary. Especially, non-viral vectors are considered to be ideal for human gene therapy, since recent adverse events with retroviral or adenoviral vectors have highlighted the issue of safety. Although we previously reported safety and high efficiency of HVJ-liposome method, we have modified the envelope of HVJ (Sendai virus). In this novel non-viral vector, the envelope of HVJ alone was utilized as a carrier to deliver proteins, genes and oligodeoxynucleotides (ODN). Thus, we optimized the transfection efficiency of HVJ-envelope vector into neonatal cardiac myocytes in this study, since cardiac myocytes is one of the most difficult cells to be transfected. HVJ-envelope, obtained after complete destruction of HVJ genome, containing FITC-labeled ODN or luciferase plasmid was incubated with cardiac myocytes. In addition, the concentration of protamine sulfate was modified (0-700 microg/ml) to increase transfection efficacy. Without HVJ-envelope vector, few cells showed fluorescence, whereas most cells demonstrated fluorescence with HVJ-envelope vector. Consistent with the high transfection efficiency of ODN, high luciferase activity was also detected using HVJ-envelope vector. Moreover, the transfection efficiency varied according to the concentration of protamine sulfate. No obvious cytotoxicity was observed in cells transfected with HVJ-envelope vector. The present study demonstrated the development of a highly efficient novel non-viral vector for cardiac myocytes, suggesting that further development may provide a new useful tool for research and clinical gene therapy in the field of cardiovascular disease.     

Expression of exogenous tissue factor pathway inhibitor in vivo suppresses thrombus formation in injured rabbit carotid arteries

OBJECTIVES: The aim of the present study was to test the hypothesis that retrovirus-mediated in vivo tissue factor pathway inhibitor (TFPI) gene transfer to the arterial wall would efficiently inhibit thrombosis without causing significant changes in systemic hemostatic variables. BACKGROUND: Acute coronary syndromes (unstable angina and acute myocardial infarction) are usually caused by atherosclerotic plaque rupture, with consequent activation of the coagulation cascade and circulating platelets. Tissue factor (TF) exposure represents an early event in this pathophysiologic sequence, leading to activation of the extrinsic coagulation pathway and thrombin formation. Tissue factor pathway inhibitor is a naturally occurring inhibitor of the extrinsic pathway. METHODS: In the present study, the gene coding for rabbit TFPI was inserted in a retroviral vector under control of a tetracycline-inducible promoter. Replication-defective, infectious, recombinant retroviruses were used to transfect rabbit carotid arteries with either TFPI or a reporter gene--green fluorescent protein (GFP). RESULTS: Retroviral-mediated arterial gene transfer of TFPI resulted in potent inhibition of intravascular thrombus formation in stenotic and injured rabbit carotid arteries, whereas transfection of the contralateral carotid artery with GFP had no effect on thrombosis. No significant changes in systemic hemostatic variables (prothrombin time and partial thromboplastin time) were observed when thrombosis was inhibited. CONCLUSIONS: These data suggest that retroviral-mediated transfection of the arterial wall with TFPI might represent an attractive approach for the treatment of thrombotic disorders.     

Vascular endothelial growth factor(165) gene transfer augments circulating endothelial progenitor cells in human subjects

Preclinical studies in animal models and early results of clinical trials in patients suggest that intramuscular injection of naked plasmid DNA encoding vascular endothelial growth factor (VEGF) can promote neovascularization of ischemic tissues. Such neovascularization has been attributed exclusively to sprout formation of endothelial cells derived from preexisting vessels. We investigated the hypothesis that VEGF gene transfer may also augment the population of circulating endothelial progenitor cells (EPCs). In patients with critical limb ischemia receiving VEGF gene transfer, gene expression was documented by a transient increase in plasma levels of VEGF. A culture assay documented a significant increase in EPCs (219%, P<0.001), whereas patients who received an empty vector had no change in circulating EPCs, as was the case for volunteers who received saline injections (VEGF versus empty vector, P<0.001; VEGF versus saline, P<0.005). Fluorescence-activated cell sorter analysis disclosed an overall increase of up to 30-fold in endothelial lineage markers KDR (VEGF receptor-2), VE-cadherin, CD34, alpha(v)beta(3), and E-selectin after VEGF gene transfer. Constitutive overexpression of VEGF in patients with limb ischemia augments the population of circulating EPCs. These findings support the notion that neovascularization of human ischemic tissues after angiogenic growth factor therapy is not limited to angiogenesis but involves circulating endothelial precursors that may home to ischemic foci and differentiate in situ through a process of vasculogenesis.     

Effect of WNT5A on epithelial-mesenchymal transition and its correlation with tumor invasion and metastasis in nasopharyngeal carcinoma

Objective:To investigate the correlation between nasopharyngeal carcinoma cell WNT5A and epithelial-mesenchytnal transition(emt)/metastasis,and investigate its possible mechanisms.Methods:RT-PCR and gene transfection were used to detect the expression of nasopharyngeal carcinoma cell strains WNT5A and EMT related factor 5-8F.Transient transfcction of NPC cell line 5-8F was determined by liposome of plasmid with WNT5A gene.The differential expressions of WNTSA and EMT-related factors in cells before and after transfection were detected by RTPCR.Cell scratch assay and Transwell assay were used to detect the motility abilities of cells before and after 5-8F transfection.Results:The expressions of WNT5A and EMT related factors matrix metalloproleinasc-2 of the WNTSA transferred group in the nasopharyngeal carcinoma cell line 5-8F were higher than the blank control group and the empty vector transferred group,and the transfer ability of the WNTSA transferred group was higher than that in the blank control group and the empty vector transferred group,while the expressions of EMT related factors E-cadherin were lower than that in the blank control group and the empty vector transferred group,and the transfer ability of the WNT5A transferred group was higher than that in the blank control group and the empty vector transferred group.Conclusions:In nasopharyngeal carcinoma cells,WNT5A can regulate the epithelial-mesenchymal transition and affect the ability of tumor invasion and metastasis of nasopharyngeal carcinoma.     

Local gene transfer of tissue factor pathway inhibitor regulates intimal hyperplasia in atherosclerotic arteries

Tissue factor (TF), the initiator of blood coagulation and thrombosis, is up-regulated after vascular injury and in atherosclerotic states. Systemic administration of recombinant TF pathway inhibitor (TFPI) has been reported to decrease intimal hyperplasia after vascular injury and also to suppress systemic mechanisms of blood coagulation and thrombosis. Here we report that, in heritable hyperlipidemic Watanabe rabbits, adenoviral gene transfer of TFPI to balloon-injured atherosclerotic arteries reduced the extent of intimal hyperplasia by 43% (P < 0.05) compared with a control vector used at identical titer (1 x 10(10) plaque-forming units/ml). Platelet aggregation and coagulation studies performed 7 days after local gene transfer of TFPI failed to show any impairment in systemic hemostasis. At time of sacrifice, 4 weeks after vascular injury, the 10 Ad-TFPI treated carotid arteries were free of thrombi, whereas two control-treated arteries were occluded (P, not significant). These findings suggest that TFPI overexpressed in atherosclerotic arteries can regulate hyperplastic response to injury in the absence of changes in the hemostatic system, establishing a role for local TF regulation as target for gene transfer-based antirestenosis therapies.     

Novel vaccines against M. tuberculosis

CDC and ACET in U.S.A. reported that novel vaccines instead of BCG are required for the protection against infection of Mycobacterium tuberculosis worldwide. However, no novel vaccine for clinical use has not yet been developed in the world including U.S.A. and Europe. We have developed two novel tuberculosis (TB) vaccines; a DNA vaccine combination expressing mycobacterial heat shock protein 65 (HSP 65) and interleukin-12 (IL-12) by using the hemagglutinating virus of Japan (HVJ)-liposome (HSP 65 + IL-12/HVJ). A mouse IL-12 expression vector (mIL-12 DNA) encoding single-chain IL-12 proteins comorised of p40 and p35 subunits were constructed. In a mouse model, a single gene gun vaccination with the combination of HSP 65 DNA and mIL-12 DNA provided a remarkably high degree of protection against challenge with virulent Mycobacterium tuberculosis; bacterial numbers were 100 fold lower in the lungs compared to BCG-vaccinated mice. To explore the clinical use of the DNA vaccines, we evaluated HVJ-liposome encapsulated HAP 65 DNA and mIL-12 DNA (HSP 65 + mIL-12/ HVJ). The HVJ-liposome method improved the protective efficacy of the HSP 65 DNA vaccine compared to gene gun vaccination. This vaccine provide remarkable protective efficacy in mouse and guinea pig models, as compared to the current by available BCG vaccine. HSP 65 + IL-12/HVJ vaccine induced CD8+cytoxic T lymphocyte activity against HSP 65 antigen. Protective efficacy of this vaccine was associated with the emergence of IFN-gamma-secreting T cells and activation of proliferative T cells as well as CTL induction upon stimulation with the HSP 65 and antigens from M. tuberculosis. Furthermore, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis, to evaluate the HSP 65 + IL-12/HVJ vaccine. Vaccination with HSP 65 + IL-12/HVJ provided better protective efficacy as assessed by the Erythrocyte Sedimentation Rate, chest X-ray findings, and immune responses than BCG. Most importantly, HSP 65 + IL-12/HVJ resulted in an increased survival for over a year. This is the first report of successful DNA vaccination against M. tuberculosis in the monkey model. Novel TB vaccines using the monkey model will be discussed in this issue. The development of novel vaccines against tuberculosis was also studied in murine and cynomolgus monkey systems. Four distinct methods; DNA vaccination (1. plasmid, 2. adenovirus vector, 3. adenoassouated virus), 4. recombinant BCG, and 5. subunit (recombinant protein) were used for the development of novel vaccines. Genes (HSP 65 gene, IL-12 gene as well as Ag 85A-, 85B-, MPB51-gene) and IL-6 related genes (IL-6 gene + IL-6R gene +gp130 gene) were administered into the Balb/c mice infected (i.v. or intra-tracheal injection) with Mycobacterium tuberculosis (M. tuberculosis). Elimination of M. tuberculosis in lungs, liver, and spleen of these mice and survival were studied in these models. HSP 65 gene + IL-12 gene vaccination, or recombinant BCG (BA51 : Antigen 85B(-) + Antigen 85A(-) + MPB51-gene recombinant BCG) were more prophylactically efficient than parental BCG Tokyo vaccination. In contrast, IL-6 related genes vaccination using adenovirus vector showed therapeutic effect on M. tuberculosis infected mice. Cytotoxic T cells (CTL) activity against M. tuberculosis in the spleen cells from mice treated with IL-6 related genes vaccination were significantly augmented. Furthermore, NOD-SCID-PBL/hu mice treated with anti-IL-2 receptor beta-chain antibody provide an useful tool for analyzing in vivo human T cell immunity against tuberculosis. In conclusion, we demonstrate the development of a novel HVJ-liposome DNA vaccine encapsulating HSP 65 DNA plus IL-12 DNA. These results suggest that HSP 65 + IL-12/HVJ could be a promising candidate for a new tuberculosis DNA vaccine, which is superior to the currently available BCG vaccine. The goal of our study is to develop a new tuberculosis vaccine superior to BCG. To this aim, we believe that the protective efficacy and protective immune responses for vaccine candidates should be addressed in larger animals, such as nonhuman primates, before proceeding to human clinical trials. Although other DNA vaccine candidates that appear to protect against virulent M. tuberculosis in mice better than BCG have failed to provide better protection than BCG in guinea pigs against aerosol challenge of a low dose of virulent M. tuberculosis, some of them are being prepared to enter early human clinical trials. More recently, we evaluated the HSP 65 + hIL-12/HVJ vaccine in the cynomolgus monkey model, which is currently the best non-human primate animal model of human tuberculosis. Monkeys were subsequently challenged with virulent M. tuberculosis by the intra-tracheal route after the third vaccination. This challenge dose normally causes death from acute respiratory infection within 4-6 months. In this particular experiment, monkeys vaccinated with HSP 65 + hIL-12/HVJ induced HSP 65-specific T-cell proliferation and improvement of chest X-P findings, resulting in an increased survival for over a year, superior to BCG group. Thus, we are taking advantage of the availability of multiple animal models (mouse, guinea pig, and monkey) to accumulate essential data of the HVJ-liposome DNA vaccine, including the vaccine efficacy and safety, for up-coming Phase I clinical trials.