反义IL-5载体构建及其对IL-5 mRNA和蛋白表达的影响

目的构建含反义IL-5的重组腺相关病毒(rAAV)asIL-5,观察rAAV asIL-5对哮喘大鼠CD+4T淋巴细胞IL-5mRNA和蛋白表达的影响。方法用基因重组方法构建反义IL5rAAV真核表达载体质粒pasIL-5/rAAV,磷酸钙沉淀法将真核表达载体质粒pasIL-5/rAAV、包装质粒pXX2、辅助质粒pXX6共转染入病毒包装细胞293细胞中,合成rAAV asIL5,Southernblot测重组病毒的滴度;将rAAV asIL5转染经密度梯度法和免疫磁珠法分离的哮喘大鼠CD+4T淋巴细胞,用半定量RT PCR、ELISA分别检测转染后细胞内IL5mRNA及细胞培养上清液中IL-5蛋白的表达水平。结果(1)成功构建并鉴定了rAAV asIL-5,滴度为1.3×1011病毒颗粒/ml;(2)病毒转染孔的相对吸光度值为1.0515±0.1477,低于对照孔(1.4271±0.1655,P<0.01);(3)细胞培养上清液中IL-5的含量病毒转染孔为(12.0840±1.4769)ng/L,低于对照组[(15.3590±1.2685)ng/L,P<0.01]。结论rAAV asIL-5能够抑制哮喘大鼠CD+4T淋巴细胞IL5mRNA和蛋白表达,为研究哮喘的基因治疗提供了实验依据。     

Precision Medicine in Catecholaminergic Polymorphic Ventricular Tachycardia: JACC Focus Seminar 5/5

In this final of a 5-part Focus Seminar series on precision medicine, we focus on catecholaminergic polymorphic ventricular tachycardia (CPVT). This focus on CPVT allows us to take a “deep dive” and explore the full extent of the precision medicine opportunities for a single cardiovascular condition at a level that was not possible in the preceding articles. As a new paradigm presented in this article, it has become clear that CPVT can occur as either a typical or atypical form. Although there is a degree of overlap between the typical and atypical forms, it is notable that they arise due to different underlying genetic changes, likely exhibiting differing mechanisms of action, and presenting with different phenotypic features. The recognition of these differing forms of CPVT and their different etiologies and mechanisms is an important step toward implementing rapidly emerging precision medicine approaches that will tailor novel therapies to specific gene defects.     

不同血清型腺相关病毒载体转染小鼠视网膜后的表达效率

目的:研究不同血清型腺相关病毒 (adeno-associated virus,AAV) 载体介导的外源基因在视网膜中的表达效率, 同时比较AAV载体和两种眼科常用启动子组合后转染小鼠视网膜的表达效率高低,为视网膜色素变性基因治疗选择合适的AAV载体与启动子提供依据。方法:AAV病毒根据衣壳蛋白不同可分为不同血清型,本课题选取视网膜疾病基因治疗中常用的AAV2/2、AAV2/5、AAV2/8和AAV2/9四种血清型AAV载体,并以绿色荧光蛋白 (green fluorescent protein, GFP) 作为报告基因,用GFP的表达强度判断AAV载体介导的外源基因在视网膜中的表达效率。AAV载体纯化后滴度为1.00×10 ¹³ mg/L,注射1 μL至C57BL/6J小鼠视网膜下腔, 于2周取眼球做成冰冻切片,在共聚焦显微镜下观察 GFP在小鼠视网膜各层的表达情况。选取在感光细胞内特异性表达最强的AAV2/8于第4周取眼球冰冻切片继续观察是否能持续稳定表达。随后选取眼科基因治疗最常用的广谱启动子CMV和由CMV增强子与鸡β-肌动蛋白启动子组成的CAG启动子,并构建AAV2/8-GFP-CMV和AAV2/8-GFP-CAG两种不同启动子的病毒载体注射至视网膜下腔,于2周取眼球做成冰冻切片,在共聚焦显微镜下观察不同启动子的AAV2/8在小鼠视网膜各层的表达情况。结果: 注射AAV-GFP后未见典型的术后细菌感染及明显免疫反应。AAV2/2、AAV2/5、AAV2/8和AAV2/9四种血清型AAV载体视网膜下腔注射2周后,AAV2/8和AAV2/9在小鼠视网膜的GFP绿色荧光明显,说明这两种AAV载体转染小鼠视网膜后的表达效率高,而在这两种血清型中,AAV2/8的GFP绿色荧光主要集中在感光细胞内,AAV2/9 在视网膜全层均有表达,说明AAV2/8对视网膜感光细胞特异性更强。对AAV2/8的进一步实验表明在视网膜下腔注射4周后小鼠视网膜的GFP绿色荧光明显,说明AAV2/8载体介导的外源基因能在体内稳定表达。使用CMV启动子时GFP在感光细胞与视网膜色素上皮细胞均有表达,而使用CAG启动子时GFP主要在感光细胞表达。结论:视网膜下腔注射AAV病毒载体可在视网膜细胞内稳定表达报告基因;AAV2/2、AAV2/5、AAV2/8和AAV2/9四种血清型AAV载体中,AAV2/8和AAV2/9在视网膜表达能力最强,AAV2/8对视网膜感光细胞特异性最好;CMV和CAG两种启动子,CAG启动子对感光细胞特异性更高。     

生育酚结合蛋白基因重组腺相关病毒的制备及抗癌作用

目的 制备生育酚结合蛋白(TAP)重组腺相关病毒,并探讨其对前列腺癌生长的作用.方法 构建重组腺相关病毒质粒pSNAV-TAP-EGFP,酶切、聚合酶链反应(PCR)、测序.225 cm2细胞培养瓶中,接种293T细胞,以重组质粒转染.扩增、纯化病毒,并转染DU-145细胞,噻唑蓝(MTT)比色法观察第2、4、6天的细胞增殖.结果 成功构建pSNAV-TAP-EGFP质粒,并制备滴度6.4×1011vg/ml、纯度95%的rAAV2-TAP.该病毒转染DU-145细胞后TAP表达量明显上升.转染后第4天,TAP转染组的细胞吸光度(A值)0.546±0.072,对照组以及空载体转染组的A值分别为0.673±0.015、0.638±0.051,生长明显受到抑制(P＜0.05).至第6天各组细胞生长差异更显著.结论 成功制备高滴度的rAAV-TAP-EGFP病毒,并可抑制前列腺癌细胞的生长.

Abstract：

Objective To produce recombinant rAAV2 virus carrying α-tocopherol associated protein (TAP) and to observe its effect on prostate cancer cells. Methods The pSNAV-TAP-EGFP plasmid was constructed and digested with restriction enzyme. Polymerase chain reaction (PCR), and sequence analysis were performed to identify the correct recombinant clones. The plasmid was transfected into 293T cells to produce virus. The virus was amplified and purified. DU-145 cells were infected by rAAV-TAPEGFP. Cell growth was detected by MTT assay. Results The pSNAV-TAP-EGFP was constructed successfully. The titer of rAAV2-TAP-virus was 6. 4 × 1011 vg/ml and the purity was 95%. The rAAV-TAP-EGFP was infected into the DU-145 cells with high efficiency. The expression of TAP was increased significantly by real-time PCR. MTT assay showed differences at the 4th day. The cellular absorbance value in the TAP transfection group, control group and empty vector transfection group was 0. 546 +0. 072, O. 673 +0. 015,and 0. 638 + 0. 051 (P ＜ 0. 05 ). The differences became more significant after 6 days. Conclusion High tier recombinant adeno-associated virus rAAV2-TAP-EGFP was obtained, which was able to inhibit the proliferation of prostate cancer cells.     

重组腺相关病毒载体表达抗表皮生长因子受体抗体对胰腺癌细胞株抑制作用的研究

目的 构建能在体内长期表达抗表皮生长因子受体(EGFR)抗体的重组腺相关病毒(rAAV)载体,观察其对人胰腺癌细胞株的抑制作用.方法 将抗人EGFR单链抗体可变区(SCFV)基因插入腺相关病毒载体的Kpn Ⅰ和BglⅡ位点,构建成含抗EGFR单链抗体基因的重组腺相关病毒载体(rAAV-anfiEGFR).设立对照组(rAAV1-EGFP组)和实验组(rAAV1-anti EGFR组),观察抗EGFR单链抗体蛋白的表达情况.采用Western blot检测抗体蛋白的表达、CCK-8法和流式细胞仪检测6种人胰腺癌细胞株(PCT-3、SW1990、Capan-1、ASPC-1、MiaPaCa-2及PANC-1细胞)的抑制率和凋亡率.两组比较采用t检验.结果 抗EGFR单链抗体蛋白能在6种人胰腺癌细胞株中表达,对照组和实验组胰腺癌ASPC-1细胞抑制率分别为1.1%±2.4%和15.1%±3.5%,两组比较,差异有统计学意义(t=6.598,P＜0.05).对照组和实验组PANC-1细胞凋亡率分别为7.0%±3.0%和11.4%±2.5%,两组比较,差异无统计学意义(t=1.952,P＞0.05);对照组和实验组SW1990、ASPC-1、Capan-1、PCT-3、MiaPaCa-2细胞凋亡率分别为1.1%±0.8%、1.5%±0.7%、1.7%±1.2%、1.1%±0.7%、2.2%±1.1%和17.6%±2.2%、46.9%±3.9%、20.0%±2.8%、12.1%±1.6%、31.1%±2.5%,两组比较,差异均有统计学意义(t=12.208,19.846,10.405,10.909,18.327,P＜0.05).结论 成功构建了携带抗EGFR单链抗体基因的rAAV载体,其表达的抗EGFR单链抗体蛋白对人胰腺癌细胞株有明显的抑制作用.     

应用杆状病毒系统制备8型腺相关病毒

目的建立应用杆状病毒系统制备8型腺相关病毒(adeno-associated virus,AAV)的技术体系,并初步检测所制备病毒的感染活力。方法采用杆状病毒生产系统包装rAAV8-EGFP,经高效液相色谱法提取并纯化病毒,实时荧光定量PCR测定病毒滴度,通过观察绿色荧光蛋白的表达强度来检测rAAV8-EGFP对HEK-293细胞的感染活力。结果实时荧光定量PCR显示成功制备高滴度rAAV8-EGFP,滴度可达1.5×1012vg/ml,100ml摇瓶共得到1.5×1013vg rAAV8-EGFP病毒颗粒;感染后的HEK-293细胞具有较强的绿色荧光蛋白表达。结论应用杆状病毒系统成功制备高滴度、高活力的重组腺相关病毒,为后续研究奠定了基础。     

Induction of hepatocellular carcinoma by in vivo gene targeting

The distinct phenotypic and prognostic subclasses of human hepatocellular carcinoma (HCC) are difficult to reproduce in animal experiments. Here we have used in vivo gene targeting to insert an enhancer-promoter element at an imprinted chromosome 12 locus in mice, thereby converting ～1 in 20,000 normal hepatocytes into a focus of HCC with a single genetic modification. A 300-kb chromosomal domain containing multiple mRNAs, snoRNAs, and microRNAs was activated surrounding the integration site. An identical domain was activated at the syntenic locus in a specific molecular subclass of spontaneous human HCCs with a similar histological phenotype, which was associated with partial loss of DNA methylation. These findings demonstrate the accuracy of in vivo gene targeting in modeling human cancer and suggest future applications in studying various tumors in diverse animal species. In addition, similar insertion events produced by randomly integrating vectors could be a concern for liver-directed human gene therapy.     

Leber遗传性视神经病变基因治疗中ND4基因腺相关病毒的构建及检测

目的构建人ND4基因腺相关病毒,为Leber遗传性视神经病变(leber hereditary optic neuropathy,LHON)的基因治疗做准备。方法人工合成人的正常ND4基因,构建rAAV2/2-ND4重组腺相关病毒,进行纯化与浓缩后,用特异扩增ND4基因的引物进行PCR鉴定,用地高辛标记的H1探针点杂交方法检测病毒液中rAAV2/2-ND4的物理滴度。结果构建的rAAV2/2-ND4重组腺相关病毒能够特异地扩增出ND4目的基因条带,基因组测定物理滴度为400×109vg·mL-1,证明该重组腺病毒携带目的基因。结论本实验成功地构建了人ND4基因腺相关病毒,作为一种先进的载体系统,为今后Leber遗传性视神经病变患者的基因治疗奠定了基础。