HIV-1相关炎性细胞因子诱导人血管内皮细胞中潜伏感染KSHV的溶解性周期复制

目的 研究HIV-1感染相关炎症细胞因子是否能够激活人脐静脉血管内皮细胞（HUVEC）中潜伏感染的卡波济肉瘤相关疱疹病毒（KSHV）；探讨该激活作用是否由KSHV Rta基因所介导。方法采用体外模拟系统，研究了与HIV-1感染T细胞诱生的细胞因子相似的重组人细胞因子对HUVEC中潜伏感染的KSHV复制的影响。通过Northern blot和定量PCR检测ORF26（该基因编码的病毒次要衣壳蛋白仅在KSHV被激活时表达）mRNA表达来分析KSHV的激活。运用KSHV Rta基因启动子（KSHV复制时最先被激活的启动子）驱动的虫荧光素酶报告基因进一步证实并扩展研究结果。结果包括干扰素-γ（IFN-γ）、肝细胞生长因子，扩散因子（HGF／SF）及制瘤蛋白M（oncostafin M，OSM）在内的重组细胞因子不仅可诱导HUVEC中潜伏感染的KSHV发生溶解性周期复制，而且能增强Rta启动子活性。结论 HIV-1感染相关的炎性细胞因子是诱导HUVEC中KSHV溶解性周期复制的因素．而日_该过程至少有部分由KSHV的Rta启动子介导．     

HIV-1包膜蛋白ENV慢病毒载体的构建及表达

目的:构建表达HIV-1包膜蛋白ENV的慢病毒载体,感染人胚肾细胞HEK293T,观察env基因在HEK293T中的表达。方法:通过点突变获得HIV-1 env完整基因,将env基因亚克隆至慢病毒穿梭载体pLVX-IRES-ZsGreen1的EcoRⅠ、XhoⅠ位点,构建重组质粒pLV-env,采用脂质体转染法转染HEK293T,经RT-PCR、Western blot检测目的基因表达,同时利用激光共聚焦技术对env基因的表达进行了定位。结果:成功获得了HIV-1 env基因,构建了重组慢病毒质粒pLV-env,RT-PCR、Western blot检测均表明外源基因能够表达,并具有抗原性,同时env基因表达后可以分泌到细胞膜表面膜上。结论:成功构建了含有HIV-1包膜蛋白env基因的重组慢病毒质粒,并验证了其表达,为下一步慢病毒的包装以及细胞模型和动物模型的构建奠定了基础。     

慢病毒载体介导的肝细胞基因转移

慢病毒(lentivirus)具有可以感染低分裂细胞的独特优势,且基因转移效率高,操作相对简便,在多种疾病的基因治疗、转基因动物的制备等方面成为引人瞩目的病毒载体。本文就慢病毒载体(lentiviral vector,LV)的特点、构建、应用,尤其是慢病毒载体对于肝细胞的基因转移进行综述。     

慢病毒载体介导的肝细胞基因转移

慢病毒（lentivirus）具有可以感染低分裂细胞的独特优势,且基因转移效率高,操作相对简便,在多种疾病的基因治疗、转基因动物的制备等方面成为引人瞩目的病毒载体。本文就慢病毒载体（lentiviral vector,LV）的特点、构建、应用,尤其是慢病毒载体对于肝细胞的基因转移进行综述。     

慢病毒载体的构建及其介导的绿色荧光蛋白在胰岛β细胞中的表达

目的获得能够在大鼠胰岛β细胞中高效表达的慢病毒载体。方法以PCR的方法扩增绿色荧光蛋白(green fluorescent protein,GFP)片段,并将其通过穿梭质粒装入pLenti6/V5表达质粒,然后用脂质体转染试剂将plenti6/V5GFP、pLP1、pLP2以及pLP/VSVG转染入293FT细胞,获得的病毒用人纤维瘤细胞系的HT1080细胞进行滴定。然后用一定滴度的慢病毒转导大鼠胰岛β细胞系INS-1,观察转导效率。结果通过限制性内切酶和琼脂糖凝胶电泳方法,观察到所克隆入pLenti6/V5表达质粒的GFP片段大小正好与PCR扩增出的片段一致。经测序验证,序列与NCBI网站上GFP序列完全一致。转染结果显示,经293FT细胞所产生的慢病毒,转导效率达到80%以上。而在1×106/ml病毒颗粒的情况下,AAV-GFP病毒几乎不能转导β细胞。结论与同一滴度的AAV-GFP病毒相比,胰岛β细胞的转导效率有非常显著的差异。即慢病毒载体表达系统在对胰岛β细胞转导的能力上,明显优于重组腺辅病毒表达系统。表明慢病毒载体在糖尿病基因治疗中,特别是对胰岛β细胞的转基因工作中,有着良好的应用前景。     

慢病毒介导的红色荧光蛋白基因在大鼠坐骨神经细胞的表达

目的 研究慢病毒载体介导的红色荧光蛋白(RFP)基因在坐骨神经雪旺细胞体内转染情况.方法 将60只Wistar大鼠随机分成A组、B组、C组和D组四个组,每组15只.四组均行右坐骨神经损伤模型,术毕向B组、C组和D组坐骨神经内注入滴度分别为2×10-6 TU、2×10-7 TU、2×10-8 TU的Lenti-RFP悬液8μl,向A组注入8μl平衡盐液(BSS)作为对照组.术后第1、2、4周观察红色荧光蛋白的表达情况,计算转染效率;并进行神经组织学检查.结果 术后第1周B、C、D组均出现RFP表达,术后第4周D组的转染效率最高.同一时间不同滴度组以及同一滴度组不同时间比较差异有统计学意义(P＜0.05).组织学检查病毒载体对神经未见明显炎性反应及组织学损伤.结论 慢病毒载体能安全有效的在体内转染雪旺细胞,并有浓度依赖性和时间依赖性,对组织无明显毒性作用.     

携人PTHLH基因慢病毒表达载体的构建

目的构建携带人甲状旁腺相关激素（PTHLH）基因的慢病毒表达载体pGC-FU/PTHLH。方法酶切载体pGC-FU,根据人PTHLH基因合成特定引物,扩增目的基因片段,将其克隆到pGC-FU质粒（含EGFP基因）上,菌落PCR鉴定及测序分析重组载体,使用Lipofectamine 2000诱导转染pGC-FU、pHelper1.0和pHelper2.0载体三质粒进入293T细胞包装慢病毒,并用带PTHLH的慢病毒感染293T细胞和鼻咽癌CEN1细胞确认慢病毒包装是否成功。结果菌液PCR产物琼脂糖凝胶电泳鉴定显示,与理论预计值阳性转化子735bp,阴性转化子198bp基本相吻合;PCR鉴定阳性的克隆进行测序和比对分析,结果完全匹配,进一步鉴定载体构建成功。分别将质粒包装系统共转染293T细胞,包装产生空白对照慢病毒（pGC-FU）和过表达PTHLH的慢病毒（pGC-FU/PTHLH）;或用携带PTHLH和EGFP基因的病毒上清感染CNE1细胞,48h后,倒置荧光显微镜下观察293T和CNE1细胞,均可见绿色荧光,转染成功。结论成功构建携人PTHLH基因慢病毒表达载体,为进一步研究PTHLH基因在鼻咽癌转移中的作用及鼻咽癌发病分子机制奠定了基础。     

慢病毒载体介导下DJ-1过表达细胞模型的建立

目的构建人野生型DJ-1及其L166P突变体的慢病毒载体并探讨慢病毒载体在构建基因过表达细胞模型中的作用。方法分别构建野生型DJ-1与L166P突变型DJ-1慢病毒载体质粒。进行测序确定比对正确后,进行质粒的大量扩增与制备并转染包装细胞系HEK293T细胞,荧光法和Western blot检测野生型DJ-1与L166P突变型DJ-1在细胞系中的表达。在确定目的蛋白正确表达之后,大量转染HEK293T细胞进行包装并生产携带目的基因的慢病毒颗粒。测定病毒上清滴度后感染PC12细胞,荧光显微镜和Western blot观察GFP荧光强度以及目的蛋白的表达,确定病毒的感染效率。结果成功构建携带DJ-1野生型及其突变体的慢病毒载体。该病毒载体可以转染进入HEK293T细胞内且目的蛋白能够正确表达。LV-DJ-1与LV-DJ-1/L166P的病毒滴度分别为2×10~9TU/m L与2×10~8TU/m L。病毒上清可以高效感染PC12细胞,绝大多数细胞可表达目的蛋白。外源野生型DJ-1和L166P突变体的蛋白表达量分别是内源性含量的315%和285%。结论慢病毒感染细胞效率很高,是很好的制备基因过表达细胞的方法。通过慢病毒载体介导,本研究获得了DJ-1及其突变体的过表达细胞模型。该模型可以用于后续DJ-1功能研究。     

HIV-Ⅰ慢病毒载体的研究进展与应用

基因治疗是治疗肿瘤、遗传病等难治性疾病的最有效手段之一,但目前的基因转移方法存在一定的局限性,成为基因治疗和广泛应用的障碍.以1型人类免疫缺陷病毒(HIV-1)为基础构建的慢病毒载体(LV)具有感染分裂及非分裂细胞、使目的 基因产物表达稳定、表达时间长、载体自身免疫原性小等优点,尤其是LV能有效诱导免疫应答,抑制肿瘤生长,诱导移植免疫耐受等,是很有发展潜力的体内基因治疗新载体.     

HIV-1 Nef蛋白通过调控 PTEN／PI3 K信号通路促进KSHV vIL-6诱导血管生成

目的探讨HIV-1 Nef蛋白能否通过调控PTEN/PI3K信号通路促进卡波氏肉瘤病毒（KSHV） vIL-6诱导血管生成。方法用脂质体转染的方法将pPTEN-cDNA、PI3K-DN及其对照空载体质粒分别转染稳定表达KSHV vIL-6和HIV-1 Nef蛋白的内皮细胞,采用微管形成试验观察微管形成状况,将这些细胞接种鸡胚绒毛尿囊膜（CAM）检测血管生成情况。 Western blot进一步检测转染了上述质粒后细胞内源性PTEN和PI3K信号分子的表达水平。结果过表达PTEN或抑制PI3K表达均可抑制Nef促进vIL-6诱导的内皮细胞微管形成和CAM血管生成。结论 HIV-1 Nef蛋白通过调控PTEN/PI3K信号通路促进KSHV vIL-6诱导血管生成。     

Multiplex PCR-based DNA array for simultaneous detection of three human herpesviruses, EVB, CMV and KSHV

Human lymphotropic herpesviruses, Epstein-Barr virus (EBV), cytomegalovirus (CMV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are responsible for a wide variety of human diseases. Due to an increase in diseased states associated with immunosuppression, more instances of co-morbid infections with these herpesviruses have resulted in viral reactivations that have caused numerous fatalities. Therefore, the development of rapid and accurate method to detect these viruses in immunocompromised patients is vital for immediate treatment with antiviral prophylactic drugs. In this study, we developed a new multiplex PCR method coupled to DNA array hybridization, which can simultaneously detect all three human herpesviruses in one single cell sample. Multiplex PCR primers were designed to amplify specific regions of the EBV (EBER1), CMV (IE) and KSHV (LANA) viral genomes. Pre-clinical application of this method revealed that this approach is capable of detecting as few as 1 copy of the viral genomes for KSHV and CMV and 100 copies of the genome for EBV. Furthermore, this highly sensitive test showed no cross-reactivity among the three viruses and is capable of detecting both KSHV and EBV viral genomes simultaneously in the lymphoblastoid cells that have been double infected with both viruses. Thus, this array-based approach serves as a rapid and reliable diagnostic tool for clinical applications.     

Functional characterization of Kaposi's sarcoma-associated herpesvirus small capsid protein by bacterial artificial chromosome-based mutagenesis

A systematic investigation of interactions amongst KSHV capsid proteins was undertaken in this study to comprehend lesser known KSHV capsid assembly mechanisms. Interestingly the interaction patterns of the KSHV small capsid protein, ORF65 suggested its plausible role in viral capsid assembly pathways. Towards further understanding this, ORF65-null recombinant mutants (BAC-?65 and BAC-stop65) employing a bacterial artificial chromosome (BAC) system were generated. No significant difference was found in both overall viral gene expression and lytic DNA replication between stable monolayers of 293T-BAC36 (wild-type) and 293T-BAC-ORF65-null upon induction with 12-O-tetradecanoylphorbol-13-acetate, though the latter released 30-fold fewer virions to the medium than 293T-BAC36 cells. Sedimentation profiles of capsid proteins of ORF65-null recombinant mutants were non-reflective of their organization into the KSHV capsids and were also undetectable in cytoplasmic extracts compared to noticeable levels in nuclear extracts. These observations collectively suggested the pivotal role of ORF65 in the KSHV capsid assembly processes.     

Expression of exogenetic enhanced green fluorescent protein in rat endocranium through lentivirus infection

The study aims to investigate whether exogenetic green fluorescent protein is able to express in the endocranium of rats, and to establish a method for further study in exogenetic gene knock-in or gene overexpression. Forty female Sprague Dawley (SD) rats were randomly divided into 4 groups with 10 in each: low and high dose groups, treated with 10% and 100% EGFP-lentivirus, respectively; negative control group, treated with virus enhancer; sham group, treated with normal saline. Seven days later, half rats’ brain tissues were perfusion fixed and fresh brain tissues were obtained from the rest after euthanasia in each group. Immunohistochemical analysis, Western blotting and RT-PCR were respectively performed to detect the site where EGFP expressed and its levels. Immunohistochemical analysis demonstrated that EGFP was successfully expressed in brain tissue of those rats infected with EGFP-lentivirus. Both Western blotting and RT-PCR showed that EGFP was expressed after treatment with EGFP-lentivirus, and the expression level increased with the dosage of the vector. Exogenetic EGFP gene can express in brain tissue of the rat, which laid a solid foundation for future studies in exogenetic gene knock in or gene overexpression.     

Antibody fragments selected by phage display against the nuclear localization signal of the HIV-1 Vpr protein inhibit nuclear import in permeabilized and intact cultured cells

The HIV-1 Vpr protein harbors a nuclear localization signal in its N-terminal domain. A peptide bearing this domain and which is designated VprN has been used as a target to screen a phage display single chain Fv (scFv) library. Here we report the isolation of anti-VprN scFv fragments from this library. The purified scFv fragments were able to bind the VprN peptide in an ELISA-based system and to inhibit VprN-mediated nuclear import in permeabilized as well as in intact microinjected cells. Furthermore, the anti-VprN scFv fragments recognized the full-length recombinant Vpr protein and inhibited its nuclear import. The same scFv fragments did not inhibit nuclear import mediated by the nuclear localization signal of the SV40 large T-antigen demonstrating a specific effect. The use of the described inhibitory anti-VprN scFv fragments to study nuclear import of viral karyophilic proteins and their therapeutic potential is discussed.     

Recombinant Vpr (rVpr) causes augmentation of HIV-1 p24 Ag level in U1 cells through its ability to induce the secretion of TNF

We have found that an HIV-1 accessory gene product Vpr enhanced HIV-1 reproduction in U1 cells chiefly by the induction of TNF, a proinflammatory cytokine, which was also known to be an activator of HIV-1 reproduction. We have generated the functional HIV-1 accessory gene product Vpr in bacterial cells. Vpr was generated in an Escherichia coli system (rVpr), purified with antibodies (Ab) to the 16 C-terminal amino acids of Vpr. The purified rVpr of 15 kDa was examined for its ability to upregulate HIV-1 reproduction in U1 cells, which is a reported function of the authentic Vpr. rVpr upregulated HIV-1 reproduction in U1 cells in a dose-dependent manner and induced the secretion of TNF. The upregulation of HIV-1 by rVpr was completely inhibited not only by anti-Vpr antibodies but also by anti-TNF antibody. These findings suggested that Vpr caused an HIV-1 reproduction in U1 cells through the induction of TNF.