逆转录病毒载体介导的人白细胞介素10在大鼠心肌细胞的表达

目的：建立一个在大鼠心肌细胞表达人白细胞介素１０（ＨｕｍａｎＩｎｔｅｒｌｅｕｋｉｎ１０,ｈＩＬ１０）的重组逆转录病毒载体基因转移系统,为下一步的研究工作做准备。方法：将构建的表达人白细胞介素１０的逆转录病毒重组体ｐＬＸ（ｈＩＬ１０）ＳＮ经ＰＡ３１７细胞包装,Ｇ４１８筛选,ＮＩＨ３Ｔ３细胞进行病毒滴度测定,选滴度最高的克隆（６×１０５ＣＦＵ／ｍｌ）作为感染大鼠心肌细胞的感染细胞;用重组逆转录病毒感染大鼠心肌细胞,应用聚合酶链反应（ＰＣＲ）及反转录聚合酶链反应（ＲＴＰＣＲ）检测转染大鼠心肌细胞ＤＮＡ及ｍＲＮＡ,应用ＥＬＩＳＡ测定ｈＩＬ１０在心肌细胞的表达。结果：外源性ｈＩＬ１０基因已整合到心肌细胞染色体ＤＮＡ并有效地转录和翻译,表达水平最高达１７５５ｎｇ／（１０６ｃｅｌｓ·２４ｈ）。结论：外源性ｈＩＬ１０基因可以转移到大鼠心肌细胞并稳定表达,为今后研究ｈＩＬ１０的作用机制及在治疗疾病中的应用打下了基础。     

Selective gene transfer to T lymphocytes using coreceptor-specific [MLV(HIV)] pseudotype vectors in a transgenic mouse model

The coreceptor usage of HIV-1 envelope proteins (Env) is mainly dependent on a defined variable region within the V3-loop of Env. Thus, retroviral vectors derived from murine leukemia virus (MLV), which have been pseudotyped with HIV-1 envelope proteins holding different V3-loops, enable selective gene delivery into either CXCR4 or CCR5 positive cultured cells. Here, we tested the distribution of CD4/CCR5-tropic [MLV(HIV)]-pseudotype vectors in transgenic mice expressing CD4 and either CXCR4 or CCR5 of human origin. The specificity of gene transfer was analyzed by ex vivo transduction of spleen cells as well as after i.v. or i.p. injection of transgenic mice. Expression of the transferred marker gene EGFP and vector sequences could be detected exclusively in lymphocytes expressing (hu)CD4 and (hu)CCR5, whereas MLV vectors pseudotyped with the VSV-G envelope glycoprotein mediated gene transfer in mice of all genotypes investigated. These data demonstrated that cell-specific gene delivery via [MLV(HIV)]-pseudotyped vectors, as previously shown for cultured cells, is also achievable in vivo.     

Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors

To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector. Expression analyses in vitro, moreover, demonstrated a widely preserved mammary cell-specific promoter activity. For in vivo analyses, xenograft tumours consisting of infected human mammary adenocarcinoma cells were established in SCID/beige mice. Immunohistochemical analyses demonstrated a hypoxia-specific, markedly increased WAP promoter-driven expression in these tumours. Thus, this retroviral vector will facilitate a targeted gene therapeutic approach exploiting the unique environmental condition in solid tumours.     

神经生长因子基因重组逆转录病毒载体的构建与鉴定

目的构建神经生长因子(NGF)基因重组逆转录病毒表达载体,研究NGF在神经干细胞(NSC)中的表达情况。方法从大鼠海马组织提取总RNA,利用RT-PCR的方法获得编码大鼠β-NGF的基因片段,应用基因重组技术,将大鼠β-NGF基因片段克隆到逆转录病毒表达载体pLEGFP-N1中,通过脂质体Lipofectamine2000转染包装细胞PT67,经G418筛选后,收集阳性克隆病毒上清,用于感染神经干细胞(NSC),观察该NSC表达的NGF对PC12细胞突起生长的作用。结果限制性内切酶酶切分析鉴定表明为正确重组子,β-NGF基因在NSC中获得表达,该NSC的培养上清液可以促进PC12细胞突起生长。结论重组逆转录病毒表达载体pLEGFP-NGF构建成功,β-NGF基因可在NSC中表达并具有生物学活性。     

RNAi-mediated knockdown of aldehyde dehydrogenase class-1A1 and class-3A1 is specific and reveals that each contributes equally to the resistance against 4-hydroperoxycyclophosphamide

PURPOSE: Aldehyde dehydrogenases class-1A1 (ALDH1A1) and class-3A1 (ALDH3A1) have been associated with resistance to cyclophosphamide (CP) and its derivatives. We have previously reported the downregulation of these enzymes by all-trans retinoic acid (ATRA). METHODS: In this study, we used siRNA duplexes as well as retrovirally expressed siRNA to knockdown one or both enzymes together in A549 lung cancer cell line in order to investigate the role of each one in mediating the resistance and the effect of the addition of ATRA. RESULTS: The results show that significant and specific knockdown of each enzyme can be achieved and that each one contributes similarly to cell resistance to 4-hydroperoxycyclophosphamide (4-HC), an active derivative of CP. Added effects were seen when both enzymes were inhibited. The addition of ATRA also exhibited additional inhibitory effects on ALDH activity and increased 4-HC toxicity when added to single siRNA aimed at one of the enzymes. On the other hand, ATRA had minimal and insignificant additional inhibitory effects on ALDH enzyme activity when added to a combination of siRNAs against both enzymes, but still increased 4-HC toxicity beyond that seen with RNAi-mediated inhibition of both enzymes together. CONCLUSIONS: We conclude that both enzymes, ALDH1A1 and ALDH3A1 will need to be blocked in order to achieve the highest sensitivity to 4-HC. Furthermore, ATRA increases 4-HC toxicity even when added to a combination of siRNAs against both enzymes, thus suggesting additional mechanisms by which ATRA can increase drug toxicity.     

重组腺病毒载体介导共刺激分子B7.1基因对儿童肝母细胞瘤体外淋巴细胞增值的影响

目的研究含hB7-1基因的重组腺病毒载体对儿童肝母细胞瘤体外淋巴细胞增值的影响。方法以腺病毒为载体,将hB7-1基因转入HepG2细胞,以FCM检测HepG2和HepG2/hB7-1细胞表面B7-1分子的表达情况。观察HepG2和HepG2/hB7-1细胞的生长曲线。用混合淋巴细胞培养法检测瘤苗对T淋巴细胞增殖的影响。结果HepG2细胞表面B7-1分子表达水平低,其阳性率为1.1%。而HepG2/hB7-1的B7-1分子表达阳性率达到18.5%,B7-1基因的表达水平提高16.8倍。HepG2和HepG2/BB-102的生长曲线相比,后者生长曲线上升减缓,生长速度减慢。B7-1分子的表达促进了淋巴细胞的增殖,较对照组有显著性差异(P<0.05)。结论1.HepG2表面B7-1分子低水平表达是其弱免疫原性的主要原因。2.含hB7-1基因的重组腺病毒载体转染HepG2可以获得B7-1分子高表达的细胞株。3.重组腺病毒载体的转染可以降低肝母细胞瘤细胞的恶性表征。4.转染含hB7-1基因的瘤苗可以促进T淋巴细胞的增殖。     

逆转录病毒载体介导hRI在小鼠模型中抑制黑色素瘤生长的研究

目的 以C57BL／6J小鼠皮下接种B16黑色素瘤为模型，研究载有抗血管生成序列的逆转录病毒载体的基因治疗系统，对黑色素瘤的抗肿瘤效应及其对血液的近期影响。方法 携带hRI的cDNA序列的重组转录病毒pLNCX—hRI颗粒被浓缩和纯化后，以空载体病毒颗粒及生理盐水为对照，静脉注射于肿瘤模型小鼠体内。检测目的基因在小鼠体内各脏器的表达水平，其对肿瘤生长的抑制作用，以及血液生化和细胞指标。结果转染后hRI基因的表达抑制了肿瘤生长，同时在观察期内无血液指标的改变。结论携带hRI基因的逆转录病毒载体基因治疗系统，可以在体内实现对B16黑色素瘤的抑制作用。     

丙型肝炎病毒cDNA与荧光素酶融合基因可调控逆转录病毒载体的构建

目的 构建丙型肝炎病毒(HCV)cDNA与荧光素酶(Luc)融合基因可调控逆转录病毒载体,以建立容易检测的HCV体外细胞模型。方法 利用基因重组技术,将HCV5’非编码区(5’NCR)和/或核心(C)区基因克隆于pGEM-Luc-DNA载体,使其与Luc基因相融合,然后再将融合基因插入可调控逆转录病毒载体(PBPSTR1)。结果pCEM-HCVl和pBPSTRl-HCV经酶切鉴定,HCV5’NCR和/或C区cDNA已与Luc基因融合,并被克隆于pBPSTRl。结论 通过体外分子克隆技术可使HCV基因cDNA带上Luc报告基因,并可克隆于逆转录病毒载体,为建立易检测的HCV细胞模型和进一步抗病毒基因治疗以及药物的筛选奠定了基础。     

Gene therapy in the treatment of intestinal inflammation

Background Local expression of anti-inflammatory or immunoregulatory genes may offer an alternative treatment of gastrointestinal inflammation.Discussion We review the basic requirements for gene therapy, the possible routes of delivery, and the different strategies for specific targeting focusing on gastrointestinal inflammation.