转FL、GM-CSF基因的人骨髓基质细胞促进脐血CD34+细胞体外扩增

研究转FL、GM-CSF基因的基质细胞对脐血CD34+细胞的扩增效应.将转FL、GM-CSF基因的入骨髓基质细胞系与脐血CD34+细胞共培养,观察细胞总数、CD34+细胞数、CFU-GM的变化情况.培养到第4周时,第(4)组(SCF+IL-3+IL-6+GM-CSF+FL)和第(8)组(HFCL/hGM-CSF+HFCL/hFL+SCF+IL-3+IL-6)的细胞总数增加到最大,分别扩增了717±24.47和709±63.63,第1周,第(5)组(HFCL+SCF+IL-3+IL-6)扩增了10.5±2.08倍,较第(8)组减少(P＜0.05).第1周时,CD34+细胞总数第(4)组和第(8)组分别扩增了8.44倍和11.5倍(P＜0.05),CD34+细胞百分率第(7)组(FCL/hFL+SCF+IL-3+II,-6)为50.2%,第(6)组(HFCL/hGM-CSF+SCF+IL-3+IL-6)为28.95%(P＜0.01).第2周,各组CFU-GM增加显著,以第(4)组和第(8)组增加最为明显,以后随扩增时间延长,造血细胞集落数、集落体积逐渐减少.表明转FL、GM-CSF基因的基质细胞,能有效的协同其他细胞因子对脐血CD34+细胞产生明显的扩增作用,能显著改变基质细胞造血功能.     

口服携带人IL-12、GM-CSF基因的减毒沙门菌抗肿瘤作用的试验

目的探讨以减毒沙门菌作为口服基因治疗载体的可行性.方法通过电转化法将真核表达载体pCMVhIL-12、pCMVhGM-CSF、EGFPN1导入减毒鼠伤寒沙门菌SL3261中,经由胃管喂给BALB/c和C57BL/6小鼠.6周后分别用4T1乳腺癌细胞和Lewis肺癌细胞进行攻击.通过流式细胞仪、共聚焦显微镜检测绿色荧光蛋白在小鼠各组织中的表达,通过PCR和ELISA法检测IL-12、GM-CSF基因的整合和表达情况.并考察肿瘤的受抑情况和小鼠的生存期.结果在小鼠的肝、脾、小肠、肾脏和肿瘤中可检测到绿色荧光蛋白的表达和相应细胞因子基因的整合.血清中相应的细胞因子水平较对照组明显升高(P<0.05),生存期远远超过对照组小鼠(P<0.05).结论减毒沙门菌可作为口服基因治疗载体,可能为肿瘤的治疗提供一条简便、安全、有效的途径.     

腺病毒介导人FL与GM-CSF联合抗肿瘤免疫基因治疗实验研究

目的:研究腺病毒介导人F lt3 ligand(hFL)与GM-CSF在体内外的表达、体外生物学活性,体内扩增小鼠脾脏DCs及抑制小鼠EL-4淋巴瘤的效应。方法:应用AdEasy系统,将hFL和hGM-CSF DNA重组到穿梭质粒的两个独立转录单位上,得到重组腺病毒Ad-hFL-hGM-CSF。采用ELISA、W estern b lot法测定重组腺病毒介导的hFL和hGM-CSF在体内外的表达情况。MTT法测定hFL和hGM-CSF刺激细胞增殖的生物学活性。利用流式细胞分析技术研究重组腺病毒对小鼠脾脏树突状细胞(DCs)的扩增情况。在移植EL-4淋巴瘤的小鼠皮下注射4次重组腺病毒(每次5×109pfu),研究其抑制肿瘤生长的功能。结果:构建得到含有双基因的重组腺病毒Ad-hFL-hGM-CSF,并在体内、外高效共表达hFL和hGM-CSF。hFL对小鼠骨髓有核细胞,hGM-CSF对TF1细胞,均有明显的刺激增殖作用。Ad-hFL-hGM-CSF显著扩增小鼠脾脏DCs至正常值的50倍。抑瘤实验中,Ad-hFL-hGM-CSF使小鼠EL-4淋巴瘤生长延慢,瘤体比对照组明显减小,抑瘤率为30%,P<0.05。病理切片显示,Ad-hFL-hGM-CSF治疗组肿瘤细胞间隙有大量淋巴细胞浸润。结论:腺病毒介导hFL和hGM-CSF在小鼠体内显著扩增脾脏DCs,并可抑制EL-4淋巴瘤的生长。     

GM-CSF对MUC1基因疫苗抑制乳腺癌生长的增强作用

目的 :观察GM CSF有无增强MUC1基因疫苗对EMT6乳腺癌生长的特异性抑制作用。方法 :采用股四头肌肌肉注射法 ,将构建的MUC1基因疫苗pcDNA3.1 MUC1免疫雌性BALB/c小鼠 ,每 3wk 1次 ,共 3次。每次基因免疫后 1、3、5d ,皮下注射GM CSF 10 0 μL(1μg/ 10 0 μL)。最后 1次基因免疫后第 3周 ,接种表达MUC1的EMT6小鼠乳腺癌细胞。两周后观察、记录肿瘤的生长情况。于肿瘤细胞接种后第 4 3天 ,处死全部动物 ,称量肿瘤的质量。用 4h51Cr释放法检测小鼠脾特异性CTL的杀伤活性。结果 :接种肿瘤细胞后 4 3d ,MUC1基因疫苗加GM CSF组、MUC1基因疫苗组、pcDNA3.1加GM CSF组及pcDNA3.1组 ,EMT6肿瘤的大小依次为 (135± 33.8)mm3 、(2 5 0± 34.3)mm3 、(5 6 8± 4 3.6 )mm3 和 (5 96± 4 8.2 )mm3 ;平均瘤质量 (g)依次为 (0 .81± 0 .4 2 )g、(1.2 3± 0 .4 1)g、(2 .30± 0 .4 8)g及 (2 .2 8± 0 .5 8)g。与对照组相比较 ,MUC1基因疫苗组EMT6肿瘤的生长受到明显抑制 (P <0 .0 5 ) ;与单独MUC1基因疫苗组相比较 ,MUC1基因疫苗加GM CSF组抗肿瘤生长的作用有显著差异 (P <0 .0 5 )。在效靶比为 10 0∶1、5 0∶1、2 5∶1和 12 .5∶1时 ,MUC1基因疫苗加GM CSF组特异性CTL对EMT6靶细胞的杀伤率 ,依次为 6 8.5 %、 5 3.4 %     

分泌粒细胞-巨噬细胞集落刺激因子的重组痘苗病毒转染的瘤苗裂解物抗肿瘤作用

将小鼠粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）基因经过同源重组得到表达ＧＭ－ＣＳＦ的重组痘苗病毒，用此痘苗病毒转染小鼠黑色素瘤细胞，制备黑色素瘤瘤苗裂解物（ＧＭ－ＣＳＦＶＭＯ），Ｃ５７ＢＬ／６小鼠皮下接种Ｂ１６－Ｆ１０细胞３天后在注射部位注射瘤苗裂解物，一周后再注射一次。结果发现ＧＭ－ＣＳＦＶＭＯ能够显著地抑制荷瘤小鼠肿瘤结节的生长并明显延长荷瘤小鼠的存活期。用此瘤苗裂解物免疫小鼠两次，间隔一周，免疫一周后给Ｃ５７ＢＬ／６小鼠皮下接种Ｂ１６－Ｆ１０细胞，结果肿瘤结节出现时间明显延长，部分小鼠肿瘤不再生长。经ＧＭ－ＣＳＦＶＭＯ治疗或免疫后小鼠的外周血和脾淋巴细胞对肿瘤细胞杀伤活性明显升高，ＮＫ活性变化不明显。本结果提示，诱导机体特异性细胞免疫可能是瘤苗裂解物的抗肿瘤作用机理之一。     

转FL基因基质细胞对脐血造血干细胞的作用

造血干细胞不足，限制了造血干细胞移植在临床的应用。我们曾探讨了持续稳定表达人FL(FLT3配体)和GMCSF(粒-巨噬细胞集落刺激因子)的转基因基质细胞系对CD34^ 细胞具有扩增作用，而在CD34^ 细胞中只有CD34^ 、CD38^-细胞才可使造血功能重建。本实验拟通过已建立的持续稳定表达人FL转基因基质细胞系，进一步探讨FL基因修饰的骨髓基质细胞对人脐血造血干细胞的体外扩增作用。     

B7.1、GM-CSF基因修饰的EL- 4细胞激发小鼠抗淋巴瘤免疫反应

目的 研究B7.1，GM-CSF基因修饰的淋巴瘤瘤苗进行恶性淋巴瘤免疫基因治疗的有效性。方法 用逆转录病毒载体分别将B7.1和GM-CSF基因导入小鼠淋巴瘤细胞EL-4中，得到EL-4/B7和EL-4/GM转基因瘤苗细胞，观察EL-4/B7和EL-4/GM瘤苗细胞对荷淋巴瘤小鼠的免疫治疗作用，以及预先接种过EL-4/B7或/和EL-4/GM瘤苗的小鼠，对野生型EL-4细胞致瘤性作用的影响，并检测接种EL-4/B7或/和EL-4/GM瘤苗的小鼠血浆IL-2及TNF-α的水平，及其脾淋巴细胞对野生型EL-4的细胞毒效应，另外，检测经EL-4/B7，EL-4/GM刺激后的小鼠脾淋巴细胞的增殖程度，结果 （1）经EL-4/B7、EL-4/GM细胞注射后，荷瘤小鼠的淋巴瘤生长速度变慢，生存时间延长，淋巴瘤组织中出现大量的炎症细胞；（2）接种一定数量的EL-4/B7，EL-4/GM细胞的小鼠，能抵抗野生型EL-4细胞的攻击；（3）接种瘤苗的小鼠血浆IL-2的水平明显升高，而TNF-α的水平无明显变化；（4）接种瘤苗的小鼠脾淋巴细胞，对野生型EL-4细胞有明显的细胞毒效应；EL-4/B7、EL-4/GM细胞能刺激小鼠脾淋巴细胞明显增殖。结论 B7.1,GM-CSF基因修饰的EL-4细胞，能有效地激发C57BL/6小鼠的抗淋巴瘤免疫反应，且B7.1基因与GM-CSF基因具有协同作用。     

人乳头瘤病毒18型L1-E6、E7嵌合基因DNA疫苗的体内免疫效应

目的：检测HPV18 L1-E6、E7嵌合基因DNA疫苗在小鼠体内的体液和细胞免疫效应。方法：将实验动物BALB/c小鼠54只随机分为9组，按不同免疫方式(肌肉接种或鼻内滴注)分别给予不同的重组质粒(pVAX1-L1-E6M3或pVAX1-L1-E7M3)和免疫佐剂(pLXHDmB7-2或LTB)。用免疫原免疫3次，末次免疫后取眼球后血进行ELISA抗体检测。末次免疫后进行小鼠足垫迟发型超敏反应(DTH)试验。断足进行小鼠足垫HE染色。取小鼠脾脏制成单细胞悬液，进行脾细胞增殖试验，并进行CD4^ /CD8^ T细胞中IFN-γ^ 或IL-4^ 细胞的FACS分析。结果：与对照组相比，各实验组均获得明显的免疫效果。实验组免疫后血清抗体4值均高于相应组别免疫前；肌肉注射组每次免疫后抗体水平较前次明显升高。实验组小鼠注射VLP抗原的左后足垫局部有红肿硬结，镜下观察可见大量单核细胞侵润。肌肉接种组的DTH反应强度、脾细胞增碹刺激指数(SI)和CD8^ IFN-γ^ 细胞数均高于鼻内滴注组；而鼻内滴注组CD4^ IL-4^ 细胞数高于单纯质粒肌肉接种组；加入pLXHDmB7-2的联合免疫组各项指标均高于单纯质粒组。结论-证实了重组pVAX1-HPV18L1/E6、E7嵌和基因DNA疫苗能诱导小鼠的体液免疫和细胞免疫效应：同时，证实B7-2分子能显著提高该质粒在小鼠体内的免疫反应效果.     

人乳头状瘤病毒16型不同基因疫苗联合免疫的实验研究

目的 探索联合免疫策略在预防和治疗人乳头状瘤病毒16型（HPV16）相关肿瘤中的作用。方法 在C57BL／6动物模型中，观察了表达HPV16基因的融合蛋白L2E7疫苗和重组痘苗病毒mE67疫苗的不同联合免疫方式在预防和治疗HPV16相关肿瘤中的作用。用酶联免疫斑点（ELISPOT）和细胞毒T淋巴细胞（CTL）反应评价它们在诱发机体产生细胞免疫应答中的作用。结果 我们发现以HPV16 L2E7融合蛋白＋佐剂（CpG）初免，用重组痘苗病毒rVVmE67加强免疫的联合免疫方式在C57BL／6小鼠实验中可以有效预防和治疗HPV16相关肿瘤的攻击。ELISPOT可以检测到高水平的E749-57肽特异性，分泌IFN-γ的效应T细胞。CTL检测同样反应出这种联合免疫方式所诱发的CTL细胞可以有效识别并杀伤含HPV16E6／E7的靶细胞。结论 以HPV16L2E7融合蛋白＋CpG初免，用重组痘苗病毒rVVmE67加强的联合免疫策略可以有效防治HPV16相关肿瘤，为进一步研究提供了科学基础。     

人FL基因高效真核表达载体的构建及其在COS—7细胞中的表达

目的：构建人FL真核表达载体－pIRS1neo/hFL,观察其在COS－7细胞 中的表达。方法：采用RT－PCR方法自人白血病细胞系TF－1中克隆可溶型FL（Flt3-ligand)cDNA片段,测序鉴定正确后,插入真核表达载体-pIRES1 neo中的EcoR Ⅰ和BamHI位点,构建hFL真核表达载体－pIRES1neo/hFL。脂质体介质法将其转染COS－7细胞,72h以RT－PCR检测转染细胞中外源hFL基因的转录、ELISA法及脐血CD34^ 细胞增殖实验测定转染细胞上清上hFL的含量和活性。结果：酶切鉴定表明成功构建了重组真核表达载体－pIRES1neo/hFL;外源hFL基因能在转染细胞中有效转录;ELISA法测得72h后培养上清中的hFL含量为每24小时251ng/10^6 cells,并且分泌的hFL具有良好的生物学活性。结论：构建hFL真核表达载体在COS－7细胞中具有良好的表达活性。     

CD自杀基因联合GM-CSF基因治疗的抗肿瘤作用及免疫机理

目的研究自杀基因与粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）基因联合治疗抗肿瘤作用及免疫机理。方法小鼠皮下接种黑色素瘤Ｂ１６Ｆ１０细胞３天后,分别在肿瘤局部直接注射表达小鼠ＧＭ－ＣＳＦ的重组腺病毒ＡｄＧＭ－ＣＳＦ和表达大肠杆菌胞嘧啶脱氨酶（ＣＤ）基因的腺病毒Ａｄ－ＣＤ,然后连续１０天腹腔注射５氟胞嘧啶（５ＦＣ）（ＡｄＣＤ／５ＦＣ／ＡｄＧＭＣＳＦ组）、单用ＡｄＣＤ／５ＦＣ组、单用ＡｄＧＭ－ＣＳＦ组、注射对照病毒ＡｄｌａｃＺ／５ＦＣ组或ＰＢＳ组。结果与接受ＡｄＣＤ／５ＦＣ、ＡｄＧＭ－ＣＳＦ、ＡｄｌａｃＺ／５ＦＣ或ＰＢＳ治疗的荷瘤小鼠比较,经联合治疗后荷瘤小鼠皮下肿瘤结节的生长明显受到抑制,荷瘤小鼠的存活期明显延长（Ｐ＜０．０１）。经ＡｄＣＤ／５ＦＣ／ＡｄＧＭＣＳＦ联合基因治疗后,肿瘤瘤体内或瘤周有大量树突状细胞、ＣＤ８＋Ｔ细胞浸润,黑色素瘤细胞表达ＭＨＣ－Ⅰ和Ｂ７－１分子明显增加,荷瘤小鼠脾细胞对Ｂ１６Ｆ１０黑色素瘤细胞特异性杀伤功能增强。结论联合应用自杀基因和ＧＭ－ＣＳＦ基因转移可以直接杀伤肿瘤细胞,又可提高机体对肿瘤的免疫应答,两者可协同发挥抗肿瘤作用     

含有RU486调控系统的质粒DNA介导的可诱导的IL-12基因在小鼠体内表达

目的 评价含有RU486调控系统的质粒DNA诱导目的 基因表达的能力.方法 将编码LacZ的pRS-LaeZ和编码小鼠IL-12的pRS22体外转染细胞或静脉快速注射入小鼠体内.X-gal染色检测培养细胞和组织中LacZ基因的表达.ELISA法检测培养细胞上清和血清中IL-12的表达水平.结果 加入RU486诱导后,在肝脏来源的HepG2细胞中约30%被染成蓝色;而不加RU486时,仅有不到1%的细胞蓝染.在其他非肝脏来源的细胞中,无论是否加入RU486诱导,都只有不到0.5%的细胞蓝染.转染pRS22的HepG2细胞,培养细胞上清中IL-12表达水平随RU486浓度的升高而增加.静脉注射pRS-LacZ后,用RU486诱导时,仅在肝脏组织中见到蓝染细胞.静脉注射pRS22后,血清中IL-12表达水平与质粒及RU486的剂量有关.结论 含有RU486调节系统的质粒DNA可以通过加入或取消RU486来开启或关闭IL-12基因的表达,而且可以通过改变质粒或RU486的剂量来调控IL-12基因的表达水平.     

Ectopic osteogenesis by ex vivo gene therapy using beta tricalcium phosphate as a carrier

Injuries and other damage to large bone can result in defects that do not heal spontaneously and lead to severe functional impairment. Better therapies are greatly needed to address this worldwide problem. The objective of the present study was to determine whether adenoviral delivery of modified human BMP2 gene (AdBMP2) using beta tricalcium phosphate (ss-TCP) as a carrier could promote osteoblastic differentiation of bone marrow mesenchymal stem cells (BMSCs) and ectopic bone formation. Rabbit BMSCs were separated from tibia aspirates and expanded in vitro. The BMSCs were then infected with AdBMP-2. Expression of BMP2, alkaline phosphatase, type I collagen, osteonectin, osteopontin, and mineralization of the cells confirmed secretion of active BMP2. Cells were observed to differentiate and maintain the osteoblast phenotype. For additional in vivo experiments, subcutaneous pockets were created on the backs of nude mice, which were then implanted with AdBMP2-BMSCs/ss-TCP, Adbetagal-BMSCs/ss-TCP, BMSCs/ss-TCP, or ss-TCP alone. The nude mice were sacrificed after 4 weeks for histological evaluation. Adbetagal-BMSCs/ss-TCP, BMSCs/ss-TCP, and ss-TCP did not show bone formation, although extensive fibrous tissue formed in the subcutaneous space in the rats implanted with ss-TCP. However, new bone tissue formation was observed on the inner walls of the pores of the ss-TCP-treated animals, and ectopic bone formation (mainly 'cartilage-bone inducing') was observed in the AdBMP2-BMSCs/ss-TCP composite. These results confirmed the osteogenic potential of BMSCs after AdBMP2 transduction and revealed that AdBMP2-BMSC/ss-TCP composites could provide the capacity for bone formation and maturation during the more advanced stages of healing.     

Nano-assemblies of J-aggregates based on a NIR dye as a multifunctional drug carrier for combination cancer therapy

The combination of chemotherapy with photothermal therapy, which may lead to improved therapeutic efficacies and reduced side effects of conventional chemotherapy, would require safe drug delivery systems (DDSs) with strong near-infrared (NIR) absorbance, efficient drug loading, and effective tumor homing ability. Herein, we fabricate nano-assemblies containing J-aggregates of a NIR dye, IR825, for drug delivery and combined photothermal & chemotherapy of cancer. It is found that IR825 could be complexed with a low-molecular-weight cationic polymer polyethylenimine (PEI), forming IR825@PEI J-aggregates with greatly enhanced NIR absorbance red-shifted to 915 nm. Those nano-assemblies of J-aggregates are further modified with polyethylene glycol (PEG), obtaining IR825@PEI-PEG nano-complex which exhibits great dispersity in physiological solutions, excellent photostability, and is able to efficiently load chemotherapeutic drug doxorubicin (DOX) via a unique strategy different from drug loading in conventional amphiphilic polymer-based DDSs. In vivo animal experiments uncover that IR825@PEI-PEG/DOX upon intravenous injection into tumor-bearing mice shows rather high tumor uptake as illustrated by photoacoustic imaging. In vivo combined photothermal & chemotherapy is then carried out, demonstrating great synergistic anti-tumor therapeutic effect remarkably superior to those achieved by the respective mono-therapies. Hence, we present a novel type of nanoscale DDSs based on nano-assemblies of small molecules without involving amphiphilic polymers, promising for imaging-guided combination cancer therapy.     

Highly metastatic variant of a mouse colon carcinoma cell line, LM17 and its response to GM-CSF gene therapy

In order to establish a highly metastatic variant of a mouse colon carcinoma cell line (CT26), BALB/c mice were first subcutaneously injected with CT26 cells. Several weeks later, metastatic tumors in lungs were resected, mechanically dispersed into a single cell suspension and cultured in vitro until cells reached confluency. These tumor cells were then subcutaneously injected into new mice. After repeating this procedure five times, a highly lung metastatic cell line, denoted as LM17, has been established. The LM17 cells grow in vitro with or without serum, whereas parental CT26 cells require serum for their growth. The LM17 cells adhere to type I collagen or fibronectin stronger than CT26 cells do. The LM17 cells invade through Matrigel-coated basement membrane in greater number than CT26 cells. By gelatin zymography, LM17 cells showed higher proteinase activity than CT26. Furthermore, subcutaneous injection of irradiated LM17 cells infected with adenovirus harboring mouse GM-CSF gene prevents the growth and lung metastasis of pre-existing subcutaneous tumor. The injection of irradiated GM-CSF-producing LM17 cells after the surgical removal of pre-existing tumor also protected the occurrence of lung metastasis. These results suggest that this highly metastatic LM17 cell line could be useful for analysis of the lung metastatic mechanism and as the mouse GM-CSF gene therapy model. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular basis of improved immunogenicity in DNA vaccination mediated by a mannan based carrier

Receptor mediated gene delivery is an attractive non-viral method for targeting genetic material to specific cell types. We have previously utilized oxidized (OMPLL) and reduced mannan poly-l-lysine (RMPLL) to target DNA vaccines to antigen presenting cells and demonstrated that it could induce far stronger immune responses in mice compared to naked DNA immunization. In this study, we describe the immune enhancing attributes of mannan-PLL mediated DNA vaccination at the molecular level. Several attributes observed in similar gene delivery conjugates, such as entry via the endocytic pathway, low toxicity, protection from nucleases and compaction of particle size, were also evident here. In addition, OMPLL and RMPLL conjugates had profound effects on the antigen presentation functions of dendritic cells and macrophages, through the stimulation of cytokine production and maturation of dendritic cells. Interestingly, we demonstrate that OMPLL–DNA and RMPLL–DNA are able to mediate dendritic cell activation via toll-like receptor 2 as opposed to mannan alone which mediates via toll-like receptor 4. Overall, this report leads to greater understanding of how oxidized and reduced mannan mediated gene delivery could augment immune responses to DNA vaccination and provide insights into ways of further improving its immunogenicity.     

逆转录病毒载体介导人类G6PD基因在人红白血病细胞中的表达

目的：探讨逆转录病毒载体介导人类G6PD基因在人白血病细胞中的表达。方法：构建G6PD cDNA的逆转录病毒表达载体pLG6PDSN,转染包装细胞PA317，病毒上清感染人红白血病细胞K562，以PCR方法检测病毒载体是否整合于细胞基因组，定量法测定G6PD表达。t检验比较转染组与对照组间的表达差异。结果：酶切鉴定表明，G6PD cDNA准确插入pLXSN相应位点，载体构建成功。转染后PCR扩增NeoR基因，证明细胞DNA整合有逆转录病毒载体。转染组与对照组酶活性测定差异有显著性（P＜0．01）。结论：本试验所构建的重组载体pLG6PDSN为严重G6PD缺陷症的基因治疗提供了表达载体。