腺病毒伴随病毒载体介导的Ⅰ型单纯疱前病毒胸苷 …

目的 研究腺病毒伴随病毒（ＡＡＶ）载体介导杀肿瘤瘤基因的转移及其在肿瘤治疗方面的应用。方法 应用作者构建的腺病毒伴随病毒载体，克隆Ⅰ型单纯疱疹病毒胸苷激酶（ＨＳＶＩ－ＴＫ）基因，构建质粒ｐＡＣＴＫ－１９。用ｐＡＣＴＫ－１９转染５型腺病毒（Ａｄ５）感染的重组ＡＡＶ包装细胞系ＡＥ１２０１，获得重组病毒ｒＡＡＶ／ＡＣＴＫ。再用此重组病毒感染肺癌细胞系Ａ５４９，并联合现氧鸟苷（ＧＣＶ）作用，研究其体外对肺     

应用S基因转染的Sp2／0细胞作为靶细胞研究HBV基因疫？…

构建编码ＨＢｓＡｇ蛋白的重组真核表达质粒ｐＣＲ３．１－Ｓ作为ＨＢＶ基因疫苗,免疫接种Ｂａｌｂ／ｃ小鼠,以重组质粒ｐＣＲ３．１－Ｓ转染的Ｓｐ２／０细胞作为靶细胞,采用＾５１Ｃｒ ４ｈ释放法,体外检测免疫小鼠的淋巴细胞杀伤功能。结果显示,与空载体对照组相比较,ＨＢＶ基因疫苗可诱导Ｂａｌｂ／ｃ小鼠产生ＨＢＶ特生细胞毒性Ｔ细胞应答,提示以Ｓｐ２／０基因转染的细胞作为靶细胞,检测免疫Ｂａｌｂ／ｃ小鼠淋巴细胞     

β—半乳糖苷酶基因的腺伴随病毒（AAV—2）载体的构建及其在…

以野生型２型人类腺伴随病毒（ＡＡＶ－２）全基因组载体（ｐＳＳＶ９和ｐＳＳＶ９－ｉｎｔ＾－）为基础，构建了重组ＡＡＶ载体ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（＋）和ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（－），制备ＡＡＶ重组病毒，感染宿主细胞后表达了β－半乳糖苷酶基因。此外，用脂质体转染法将载体导入２９３细胞和Ａ５４９细胞，进行了ＬａｃＺ基因瞬时表达研究。结果显示，重组ＡＡＶ载体（ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（＋））     

复制缺陷型人IL-2重组腺病毒的制备与鉴定

目的将人ＩＬ－２的重组腺病毒载体与Ａｄ５腺病毒ＤＮＡ末端肽复合物同源重组，高效制备人ＩＬ－２的复制缺陷型重组腺病毒，并进行体外表达和活性检测。方法将含全部编码序列的人ＩＬ－２ｃＤＮＡ置于真核表达载体ｐＣＩｃｃ的ＣＭＶ启动子下游，切出含ＣＭＶ启动子、人ＩＬ－２ｃＤＮＡ和ＳＶ４０ｐｏｌｙＡ信号肽序列的ＣｌａＩ片段，插入Ｅ１区替代的腺病毒载体ｐＡｘｌｏｗ，选择左向转录的人ＩＬ－２重组腺病毒载体ｐＡｘｌｃｗ．ＣＩｈＩＬ－２与经ＥｃｏＴ２２Ⅰ酶切的Ａｄ５腺病毒ＤＮＡ－末端肽复合物共转染２９３细胞；通过同源重组获得人ＩＬ－２的复制缺陷型重组腺病毒；体外转染人宫颈癌ＨｅＬａ细胞、人Ｔ细胞淋巴瘤Ｈｕｔ７８细胞和原代人皮肤成纤维细胞。结果扩增到的病毒滴度达２．１×１０９ＰＦＵ／ｍｌ；体外转染的人肿瘤细胞均检测到ＩＬ－２的表达（４００～２６００Ｕ／１０６细胞／２４小时）。结论所制备的复制缺陷型重组腺病毒能有效介导人ＩＬ－２的基因转移，可望用于肿瘤基因治疗的临床研究。     

β－半乳糖苷酶基因的腺伴随病毒（AAV－2）载体的构建及其在哺乳类细胞中的表达

以野生型２型人类腺伴随病毒（ＡＡＶ－２）全基因组载体（ｐＳＳＶ９和ｐＳＳＶ９－ｉｎｔ－）为基础，构建了重组ＡＡＶ载体ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（＋）和ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（－），制备ＡＡＶ重组病毒，感染宿主细胞后表达了β－半乳糖苷酶基因。此外，用脂质体转染法将载体导入２９３细胞和Ａ５４９细胞，进行了ＬａｃＺ基因瞬时表达研究。结果显示，重组ＡＡＶ载体（ＰＳＳＶ９／Ｐ４０－ＬａｃＺ（＋））ＬａｃＺ基因表达的动态变化特点是，转染后表达较早（１２～２４ｈ）出现，并迅速达到高峰值（经２４ｈ），随后较快下降（经４８～７２ｈ）并维持在较低水平。将启动子附近ｉｔｒ结构有差别的上述两载体转染宿主细胞７２ｈ后做表达水平比较，结果ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（－）在２９３细胞和Ａ５４９细胞中，ＬａｃＺ表达水平均高于ｐＳＳＶ９／Ｐ４０－ＬａｃＺ（＋）（１．２倍～１．４倍），提示启动子附近ＡＡＶｉｔｒ结构的变异对表达有一定的影响。     

应用S基因转染的Sp2/0细胞作为靶细胞研究HBV基因疫苗的细胞免疫应答

构建编码ＨＢｓＡｇ 蛋白的重组真核表达质粒ｐＣＲ３－１Ｓ作为ＨＢＶ 基因疫苗, 免疫接种Ｂａ１ｂ／ｃ 小鼠。以重组质粒ｐＣＲ３－１Ｓ转染的Ｓｐ２／０ 细胞作为靶细胞, 采用５１Ｃｒ ４ｈ 释放法, 体外检测免疫小鼠的淋巴细胞杀伤功能。结果显示, 与空载体对照组相比较, ＨＢＶ基因疫苗可诱导Ｂａｌｂ／ｃ 小鼠产生ＨＢＶ 特异性细胞毒性Ｔ 细胞应答（ Ｐ＞ ０－０５） , 提示以Ｓｐ２／０ 基因转染的细胞作为靶细胞, 检测免疫Ｂａｌｂ／ｃ 小鼠淋巴细胞的杀伤功能是可靠的。     

复制缺陷型鼠IL-3重组腺病毒的构建和鉴定

构建以ＣＭＶ启动子控制鼠ＩＬ－３基因表达的复制缺陷型腺病毒（ＡｄＣＭＶＩＬ－３）。将含全部编码序列的鼠ＩＬ－３ｃＤＮＡ克隆于腺病毒穿梭质粒ｐＭＨ４的ＣＭＶ启动子下游,再与含腺病毒基因组的质粒ｐＢＨＧ１０共转染２９３细胞,经细胞内同源重组后产生７个病毒空斑,取其中４个空斑扩增后经双引物ＰＣＲ检测,结果均含有ＩＬ－３及腺病毒特有片段,表明成功地构建了携带鼠ＩＬ－３基因的复制缺陷型重组腺病毒。     

携带hIL-2cDNA的逆转录病毒载体的构建及其在人肝癌细胞中的特异表达研究

将人白细胞介素２（ｈＩＬ-２）ｃＤＮＡ克隆到逆转录病毒载体ＭＮＳＭ的ＰＬ位点　，分别构建了转录受ＳＶ４０早期启动子和人甲胎蛋白增强子调控的重组逆转录病毒载体ＭＮＳＩ和ＭＮＳＩＡ。用脂质体转染法将ＭＮＳＩ和ＭＮＳＩＡ分别转导ＰＡ３１７包装细胞，测质粒转染率为（５～２０）×１０~(－３)克隆／μｇＤＮＡ·１０~６细胞，病毒感染率为（５．４～４５０）×１０~４ＣＦＵ／ｍｌ。重组病毒在４μｇ／ｍｌ ｐｏｌｙｂｒｅｎｅ存在条件下感染人肝癌细胞、肾癌细胞和黑色素瘤细胞，Ｎｅｏ~Ｒ克隆经Ｓｏｕｔｈｅｒｎｂｌｏｔ分析证明ｈＩＬ－２ｃＤＮＡ转入人肿瘤细胞并整合，　Ｒ　ＮＡ斑点杂交及ＩＬ－２活性表达分析证明，人甲胎蛋白增强子可促进异源启动子启动ｈＩＬ－２ｃＤ－ＮＡ在合成甲胎蛋白的人肝癌细胞中高效特异转录和表达。该研究对肝癌特异性免疫增强基因治疗有重要意义。     

小鼠淋巴细胞趋化因子重组腺病毒载体的构建及其在骨髓树突状细胞中的表达

经ＲＴ－ＰＣＲ克隆小鼠淋巴细胞趋化因子（Ｌｙｍｐｈｏｔａｃｔｉｎ，Ｌｔｎ）的全长编码ｃＤＮＡ，将其置于ＣＭＶ启动子下游，插入Ｅ１区替代的腺病毒载体ｐＡｘ１ｃｗ。Ｌｔｎ重组腺病毒载体ｐＡｘ１ｃｗ．ＣＩｍＬｔｎ与经ＥｃｏＴ２２Ｉ酶切的Ａｄ５腺病毒ＤＮＡ－末端肽复合物共转染２９３细胞，制备Ｌｔｎ重组腺病毒，扩增到的病毒滴度为３．６×１０９ｐｆｕ／ｍｌ。用重组ＧＭ－ＣＳＦ从小鼠骨髓中扩增到的树突状细胞本身并不表达Ｌｔｎ；体外感染Ｌｔｎ重组腺病毒后４ｈ即可经ＲＴ－ＰＣＲ检测到Ｌｔｎ的表达，其２４ｈ的细胞培养上清体外对ＣＤ４＋Ｔ细胞和ＣＤ８＋细胞具有显著的趋化活性，表明所制备的Ｌｔｎ重组腺病毒能有效介导Ｌｔｎ在树突状细胞中的表达，为研究Ｌｔｎ基因修饰的树突状细胞诱导Ｔ细胞免疫应答奠定基础。     

人可溶性IL-6R基因在COS7细胞中的表达及活性分析

目的在ＣＯＳ７细胞中表达具有生物学功能的人可溶性ＩＬ－６Ｒ（ｓＩＬ－６Ｒ），作为研究ｓＩＬ－６Ｒ结构与功能关系的基础。方法首先利用ＰＣＲ技术扩增出人可溶性ＩＬ－６Ｒ（ｈｓＩＬ－６Ｒ）编码基因片段，并重组入克隆载体ｐＡＬＴＥＲ－１。通过基因序列分析确定了目的基因的核苷酸序列，并进一步构建了由ＳＶ４０晚期启动子和ＨＣＭＶ早期启动子控制的表达质粒ｐＳＶＬ６Ｒ和ｐＣＭＶ６Ｒ。用脂质体介导的方法将表达质粒转染ＣＯＳ７细胞，并分别在ｍＲＮＡ水平（斑点杂交）和蛋白水平（ＥＬＩＳＡ和Ｗｅｓｔｅｒｎ－ｂｌｏｔ）检测ｓＩＬ－６Ｒ基因在ＣＯＳ７细胞中的表达。在７ＴＤ１，ＬＴ１２两种ＩＬ－６反应细胞系上检测转染细胞上清（含ｓＩＬ－６Ｒ）的生物学活性。结果在ｍＲＮＡ水平和蛋白水平分别检测到ｓＩＬ－６Ｒ基因在ＣＯＳ７细胞中的表达，表达产物分子量约为５００００。表达产物在７ＴＤ１，ＬＴ１２细胞系上检测到明显的生物学活性。结论天然ｓＩＬ－６Ｒ基因在ＣＯＳ７细胞中的成功表达为进一步制备ｓＩＬ－６Ｒ突变体及其结构与功能关系的研究奠定了基础     

Inhibition of adenovirus cytotoxicity, replication, and E2a gene expression by adeno-associated virus

Adeno-associated virus (AAV) and the other parvoviruses have long been known to inhibit proliferation of nonpermissive cells. The mechanism of this inhibition is not thoroughly understood. To learn how AAV interacts with host cells, we have begun an investigation into AAV's relationship with adenovirus (Ad), AAV's most efficient helper virus. AAV, but not UV-inactivated AAV, delayed Ad-induced cytotoxicity and inhibited Ad E2a gene expression. AAV, but not UV-inactivated AAV or a recombinant AAV vector, inhibited Ad DNA replication. To determine whether AAV or its replication (Rep) proteins alter Ad early gene expression, we measured steady state E2a mRNA levels in AAV and Ad coinfected cultures and in a cell line (Neo6) that inducibly expresses the Rep proteins. AAV, but not UV-AAV, and Rep expression resulted in diminution of E2a protein and mRNA levels. To determine whether the AAV Rep proteins directly affect the individual Ad early promoters, we constructed luciferase reporter plasmids containing each of the five early promoters. Cotransfection of Ad-luciferase and an AAV rep gene-expressing plasmid in HeLa cells demonstrated that Rep78 repressed the E1a, E2a, and E4 promoters but trans-activated the E1b and E3 promoters. In the presence of a cotransfected E1a-expressing plasmid, Rep78 repressed expression from all five promoters. These results indicate that Rep may have different effects on the Ad early promoters dependent upon the presence of the E1a trans-activating protein.     

Evaluation of risks related to the use of adeno-associated virus-based vectors

Recombinant AAV efficacy has been demonstrated in numerous gene therapy preclinical studies. As this vector is increasingly applied to human clinical trials, it is a priority to evaluate the risks of its use for workers involved in research and clinical trials as well as for the patients and their descendants. At high multiplicity of infection, wild-type AAV integrates into human chromosome 19 in approximately 60% of latently infected cell lines. However, it has been recently demonstrated that only approximately 1 out of 1000 infectious units can integrate. The mechanism of this site-specific integration involves AAV Rep proteins which are absent in vectors. Accordingly, recombinant AAV (rAAV) do not integrate site-specifically. Random integration of vector sequences has been demonstrated in established cell lines but only in some cases and at low frequency in primary cultures and in vivo. In contrast, episomal concatemers predominate.Therefore, the risks of insertional mutagenesis and activation of oncogenes are considered low. Biodistribution studies in non-human primates after intramuscular, intrabronchial, hepatic artery and subretinal administration showed low and transient levels of vector DNA in body fluids and distal organs. Analysis of patients body fluids revealed rAAV sequences in urine, saliva and serum at short-term. Transient shedding into the semen has been observed after delivery to the hepatic artery. However, motile germ cells seemed refractory to rAAV infection even when directly exposed to the viral particles, suggesting that the risk of insertion of new genetic material into the germ line is absent or extremely low. Risks related to viral capsid-induced inflammation also seem to be absent since immune response is restricted to generation of antibodies. In contrast, transgene products can elicit both cellular and humoral immune responses, depending on the nature of the expressed protein and of the route of vector administration. Finally, a correlation between early abortion as well as male infertility and the presence of wt AAV DNA in the genital tract has been suggested. Although no causal relationship has been established, this issue stresses the importance of using rAAV stocks devoid of contaminating replication-competent AAV. This review comprehensively examines virus integration, biodistribution, immune interactions, and other safety concerns regarding the wild-type AAV and recombinant AAV vectors.     

Long-term expression of a transferred gene in Epstein-Barr virus transformed human B cells

Delivering a gene into the Epstein-Barr virus (EBV)-transformed B cells is useful in studying effects of the gene on B-cell functions. However, although people have been able to efficiently transfer genes into and get them expressed in B-lympho blastoid cells for a time probably long enough to kill the cells using vectors harbouring oriP, the expression time of the delivered gene is not long enough in order to study the gene function in B cells. To solve this problem, we constructed an adeno-associated virus (AAV) plasmid pAGX(+) based on plasmids pSub201 and pRc/CMV. We developed and packaged recombinant AAV (rAAV) expression vectors containing an antisense or a sense DNA fragment of 6A8 cDNA encoding a human alpha-mannosidase, or an antisense fragment of 5D4 cDNA encoding a human cell membrane protein, or EYFP DNA. EBV-transformed B cell SKW6 and 3D5 were transduced with those rAAV or the mock. Transduction with the rAAV-EYFP showed an infection frequency of 64 +/- 3.5% and 58 +/- 6.2% for SKW6 and 3D5 cell, respectively. Genomic polymerase chain reaction (PCR) for neoR gene indicated an integration of the transferred gene into the host DNA. After being cultured and propagated for over 12 months, the cells were detected for the expression of the transferred gene. The RT-PCR, enzymatic assay and Con A binding test demonstrated an inhibition of 6A8 alpha-mannosidase in both SKW6 and 3D5 cells transduced with the antisense 6A8 DNA. Immunofluorescence staining with monoclonal antibodies (MoAb) 5D4 showed a reduction of the 5D4 protein expression on both the cells transduced with the antisense 5D4 DNA. The DNA fragmentation assay showed a resistance of the cells with 6A8 alpha-mannosidase inhibition to apoptosis induction by anti-Fas antibody. The data indicate that the AAV vector pAGX(+) can efficiently introduce genes into EBV-transformed B cells and the delivered gene can be expressed in the cells for more than 12 months which may be long enough for the study of gene functions in B cells.     

Adeno-associated viral vectors as gene delivery vehicles

Adeno-associated virus (AAV), a non-pathogenic human parvovirus, is gaining attention for its potential use as a human gene therapy vector. One of the most attractive features of recombinant AAV vectors is the ability to be stably maintained in host cells as integrated proviruses. This property is particularly desireable for therapies requiring long-term correction of a genetic defect. This review highlights recent advances made in the AAV field and will discuss some limitations of rAAV vector integration. A novel method for enhancing the integration efficiency of these vectors will be presented.     

一组可提供AAV载体复制和包装功能的重组HSV-1

目的 构建一组具有AAV载体复制和包装功能的重组HSV-1，从中选出功能较强者用于重组AAV的生产。方法 采用一套含有HSV-1基因组的粘粒系统构建重组HSV-1。首先将2型腺病毒伴随病毒（AAV-2）rep基因的起始密码子ATG人工定点突变成ACG；然后将自身启动子控制下的AAV-2rep(起始密码子突变或未突变）和cap基因分别插入粘粒上HSV-1的UL2基因或UL44基因，构建成重组粘粒cos6-rmc/△UL2,cos56-rc/△UL44cos56-rmc/△UL44；将重组粘粒上的HSV-1片段分别与HSV-1的其余片段进行同源重组，得到3株重组HSV-1，连同过去报道的一株重组HSV-1一起，分别命名为HSV1-rc/△UL2,HSV1-rmc/△UL2,HSV1-rc/△UL44,HSV1-rmc/△UL44。结果 4株重组HSV-1经PCR鉴定均含有rep基因，分别感染携带绿色荧光蛋白（GFP）基因的AAV载体细胞株后均能产生重组AAV，重组AAV可在BHK-21细胞中表达GFP，HSV1-rc/△UL2和HSV1-rmc/△UL2对AAV载体的包装能力明显强于HSV1-rc/△UL44和HSV1-rmc/△UL44。结论 构建的4株重组HSV-1均具有复制和包装重组AAV的能力，其中HSV1-rc/△UL2和HSV1-rmc/△UL2功能较强，有望用于重组AAV的大规模生产。     

Stable transduction of large DNA by high-capacity adeno-associated virus/adenovirus hybrid vectors

Viral vectors with high cloning capacity and host chromosomal integration ability are in demand for the efficient and permanent genetic modification of target cells with large DNA molecules. We have generated a hybrid gene transfer vehicle consisting of recombinant adeno-associated virus (AAV) replicative intermediates packaged in adenovirus (Ad) capsids. This arrangement allows cell cycle-independent nuclear delivery of recombinant AAV genomes with lengths considerably above the maximum size (i.e., 4.7 kb) that can be accommodated within AAV capsids. Here we show that high-capacity AAV/Ad hybrid vector gene transfer mediates cellular genomic integration of large fragments of foreign DNA and accomplishes stable long-term transgene expression in rapidly proliferating cells. Southern blot and polymerase chain reaction analyses of chromosomal DNA extracted from clones of stably transduced cells revealed that most of them contained a single copy of the full-length hybrid vector genome with AAV inverted terminal repeat (ITR) sequences at both ends. The high-capacity AAV/Ad hybrid vector system can thus be used for the transfer and expression of transgenes that cannot be delivered by conventional integrating viral vectors.     

rAAV2/1-Acrp30病毒的纯化、扩增与活性检测

目的 将大鼠脂联素基因(Acrp30)克隆到腺相关病毒(AAV)载体中,经包装、纯化、扩增后获得rAAV2/1-Aerp30病毒,并进行活性检测.方法 筛选阳性克隆获得pSNAV2.0-Acrp30,EcoR Ⅰ/Sal Ⅰ双酶切鉴定,并行测序.转染BHK21细胞,G418筛选培养,获得抗药克隆细胞株.HSV1-re/△UL2感染,包装此细胞株并收获病毒载体rAAV2/1-Acrp30.行DNA斑点杂交法测定病毒滴度,SDS-PAGE分析判断病毒纯度,Western blot法检测目的 蛋白脂联素在HEK293细胞中的表达活性.结果 PCR电泳及酶切鉴定表明,pSNAV2.0-Acrp30重组成功,基因测序显示装入pSNAV2.0质粒中的Acrp30基因正确.rAAV2/1-Acrp30病毒的大致滴度为1.0×1012μg/ml,HEK293细胞分泌蛋白浓度为50 ng/ml,病毒载体纯度在95%以上.结论 实验获得的脂联素病毒载体滴度高、感染性好,可试用于GK(Goto-Kakizaki)大鼠脂联素转基因治疗.