Intravenous injection of an adenovirus encoding hepatocyte growth factor results in liver growth and has a protective effect against apoptosis

BACKGROUND: Hepatocyte growth factor/scatter factor (HGF/SF) is a pleiotropic cytokine with mitogenic, motogenic and morphogenic effects for a wide variety of cells. Previous studies have reported that the in vivo infusion in normal, untreated mice of recombinant HGF results in low levels of DNA synthesis and liver proliferation. In this study, we examined whether liver regeneration could be obtained by the in vivo injection of a recombinant adenoviral vector encoding human HGF (Ad.CMV.rhHGF) in normal, intact mice. MATERIALS AND METHODS: C57BL/6 mice were infused intravenously with doses increasing from 1 to 4 x 1011 particles of the recombinant human HGF (rhHGF) adenoviral vector or with a control virus encoding Escherichia coli beta-galactosidase (Ad.CMV.lacZ). At day 5, mice were sacrificed and evaluated for the presence of hepatocyte mitogenesis and liver regeneration (5-bromo-2''-deoxyuridine (BrdU) assays and liver weight determination) and for the presence of liver damage (serum alanine amino-transferase (ALT) measurements and TUNEL assays). RESULTS: In vivo administration of rhHGF stimulated DNA synthesis of hepatocytes and liver weight in a dose-dependent fashion. The maximal effect was seen after the infusion of 3 x 1011 particles which resulted at day 5 in >130% increase in relative liver mass with little cytopathic effect. In contrast, administration of the lacZ adenoviral vector caused little hepatocyte replication, but induced high levels of serum ALT (approximately 3 times higher than the rhHGF vector) and significant apoptotic cell death. CONCLUSIONS: This study shows that a single injection of Ad.CMV.rhHGF alone is able to induce in vivo and in a very short period of time, robust DNA synthesis and liver proliferation in normal mice without liver injury or partial hepatectomy. This recombinant adenoviral vector has a lower toxicity than the control lacZ adenovirus. This suggests that HGF may have a protective effect against adenovirus-induced pathology.     

Recombinant Interferon-γ Lentivirus Co-Infection Inhibits Adenovirus Replication Ex Vivo

Recombinant interferon-γ (IFNγ) production in cultured lentivirus (LV) was explored for inhibition of target virus in cells co-infected with adenovirus type 5 (Ad5). The ability of three different promoters of CMV, EF1α and Ubiquitin initiating the enhanced green fluorescence protein (GFP) activities within lentiviruses was systematically assessed in various cell lines, which showed that certain cell lines selected the most favorable promoter driving a high level of transgenic expression. Recombinant IFNγ lentivirus carrying CMV promoter (LV-CMV-IFNγ) was generated to co-infect 293A cells with a viral surrogate of recombinant GFP Ad5 in parallel with LV-CMV-GFP control. The best morphologic conditions were observed from the two lentiviruses co-infected cells, while single adenovirus infected cells underwent clear pathologic changes. Viral load of adenoviruses from LV-CMV-IFNγ or LV-CMV-GFP co-infected cell cultures was significantly lower than that from adenovirus alone infected cells (P = 0.005–0.041), and the reduction of adenoviral load in the co-infected cells was 86% and 61%, respectively. Ad5 viral load from LV-CMV-IFNγ co-infected cells was significantly lower than that from LV-CMV-GFP co-infection (P = 0.032), which suggested that IFNγ rather than GFP could further enhance the inhibition of Ad5 replication in the recombinant lentivirus co-infected cells. The results suggest that LV-CMV-IFNγ co-infection could significantly inhibit the target virus replication and might be a potential approach for alternative therapy of severe viral diseases.     

Fiber-knob modifications enhance adenoviral tropism and gene transfer in malignant glioma

BACKGROUND: Malignant gliomas remain refractory to Ad5-mediated gene therapy due to deficiency of the coxsackie adenovirus receptor on tumor cells. The purpose of this study was to evaluate whether changes in adenoviral tropism can enhance gene transfer in the context of malignant glioma. METHODS: We have identified several receptors that are over-expressed on tumor cells and created a series of pseudotyped Ad5 vectors that recognize these receptors: Ad5-RGD which binds alpha(v)beta3/alpha(v)beta5 integrins; Ad5/3 which contains adenovirus serotype 3 knob and binds to CD46; Ad5-Sigma which incorporates the reovirus sigma knob and binds to junctional adhesion molecule-1; and Ad5-pk7 which contains the polylysine motif and binds heparan sulfate proteoglycans. We also investigated the Ad5-CAV1 vector, which contains the knob of canine adenovirus type 1, a virus previously shown to infect glioma via an unknown mechanism. In this study, we compared these modified vectors for their ability to promote the expression of luciferase transgene both in vitro and in vivo. RESULTS: Our results indicate that all five modified vectors attained higher mean luciferase activity vs. control. Among them, Ad5-CAV1 and Ad5-pk7 attained the highest transduction efficiency independent of different tumor lines or infection time. Ad5-Sigma and Ad5-pk7 also demonstrated the least nonspecific infection in normal human astrocytes. Most importantly, Ad5-pk7 achieved 1000-fold increased transgene expression in human glioma xenografts in vivo. CONCLUSIONS: These results indicate that modifications of adenoviral tropism can enhance gene transfer in tumors that are poorly susceptible to adenoviral vectors and warrant further development of Ad5-pk7 for glioma gene therapy.     

Head and neck cancer cells are efficiently infected by Ad5/35 hybrid virus

BACKGROUND: Clinical gene therapy trials using standard Ad5-based vectors have thus far demonstrated limited efficacy, most likely due to low expression levels of adenoviral receptors on tumor cells. We sought to analyze adenoviral receptor expression levels on primary head and neck squamous cell carcinoma (HNSCC) cells and to determine whether adenoviral retargeting to the CD46 receptor via the Ad5/35 system would increase therapeutic potential for HNSCC. METHODS: We used flow cytometric analyses to determine adenoviral receptor expression levels on nine primary HNSCC cells collected from cancer patients. Adenoviruses Ad5.LacZ and Ad5/35.LacZ were used to analyze the differences in viral transduction both in vitro and in a HNSCC tumor mouse model. RESULTS: Flow cytometric analyses demonstrated uniformly high CD46 expression in all cells studied (85-99%). In contrast, coxsackievirus and adenovirus receptor (CAR) expression was substantially lower and highly variable (1.6-62%). Alpha(v) integrin expression was between 39-98%. In situ stainings for beta-galactosidase gene expression demonstrated that Ad5/35.LacZ was clearly more effective than Ad5.LacZ in transducing primary HNSCC cells. Quantification of beta-galactosidase expression revealed up to 65 times higher transgene expression from Ad5/35.LacZ than Ad5.LacZ. In vivo, beta-galactosidase expression was detected in a substantial area after a single intratumoral injection of Ad5/35.LacZ, whereas injection with Ad5.LacZ resulted in gene expression only in a few cells. CONCLUSIONS: Our results demonstrate that the low and variable CAR expression levels limit the therapeutic efficacy of Ad5-based strategies for HNSCC. In contrast, the effective in vivo transduction capacity of Ad5/35 warrants further development of this vector for the treatment of head and neck cancer.     

表达丙型肝炎病毒NS3抗原的重组腺病毒构建及体外表达

为探索研制丙型肝炎疫苗的新途径,以期获得防治丙型肝炎的重组腺病毒减毒活疫苗,我们构建了表达丙型肝炎病毒(Hepatitis C virus ,HCV)非结构蛋白3(non structural protein 3,NS3)抗原的重组腺病毒RAd NS3,并检测其在体外表达。应用PCR从真核表达质粒pRC/NS3 中扩增编码HCV NS3 蛋白(329-935aa)的基因片段,定向克隆到重组腺病毒AdEasy-1系统的穿梭质粒pAdTrack CMV上,采用细菌内同源重组"两步转化法"构建携带HCV NS3基因的重组腺病毒基因组质粒pAd HCV NS3,转染293 细胞,成功包装出重组腺病毒RAd NS3,利用它有效地感染人肝癌细胞株HepG2,经RT PCR及免疫印迹等不同方法检测表明,被感染细胞能表达HCVNS3蛋白,为后续进行重组腺病毒在动物体内诱导抗HCV免疫应答能力的研究奠定了基础。     

经NGR肽段遗传修饰的携带三种报告基因的腺病毒载体的构建及其实验研究

NGR(Asn-Gly-Arg)是通过噬菌体展示技术筛选出来的能够和肿瘤新生血管特异结合的三肽模体,可以将多种药物分子和病毒载体靶向运输到肿瘤或者进行血管再生的组织中。为此构建了腺病毒衣壳蛋白knob的HI环(HI-loop)经NGR肽段修饰的并同时表达三种报告基因的腺病毒载体Ad5/E1-mCherry/E3-luciferase-2A-eGFP/knob-NGR。体内、外实验研究表明,该病毒载体可成功表达三种报告基因;经NGR肽段修饰的腺病毒载体对人乳腺癌细胞系MDA-MB-231的感染效率高于未经修饰的对照腺病毒Ad5CMVeGFP。该载体的成功构建为进一步研究经NGR肽段修饰的腺病毒在肿瘤动物模型体内的靶向性及经NGR肽段修饰的并携带治疗基因的实验治疗研究奠定了基础。     

Protective effect of a prime-boost strategy with plasmid DNA followed by recombinant adenovirus expressing TgAMA1 as vaccines against Toxoplasma gondii infection in mice

A heterologous prime-boost strategy with priming plasmid DNA followed by recombinant virus expressing relevant antigens is known to stimulate protective immunity against intracellular parasites. In this study, we have evaluated a heterologous prime-boost strategy for immunizing mice against Toxoplasma gondii infection. Our results revealed that the prime-boost strategy using both plasmid DNA and adenoviral vector encoding TgAMA1 may stimulate both humoral and Th1/Th2 cellular immune responses specific for TgAMA1. Moreover, C57BL/6 mice immunized with the pAMA1/Ad5Null, pNull/Ad5AMA1, and pAMA1/Ad5AMA1 constructs showed survival rates of 12.5%, 37.5%, and 50%, respectively. In contrast, all the pNull/Ad5Null immunized mice died after infection with the PLK-GFP strain of T. gondii. Brain cyst burden was reduced by 23% in mice immunized with pAMA1/Ad5AMA1 compared with the pNull/Ad5AMA1 immunized mice. These results demonstrate that the heterologous DNA priming and recombinant adenovirus boost strategy may provide protective immunity against T. gondii infection.     

Cutting edge: restoration of the ability to generate CTL in mice immune to adenovirus by delivery of virus in a collagen-based matrix

Viruses are commonly used for the delivery of genes coding for tumor-associated Ags to elicit tumor-specific immune responses. The success of viral vectors has been limited in preclinical and clinical trials in part because of antiviral immunity. We investigated the ability of a collagen-based matrix (Gelfoam; Pharmacia and Upjohn, Kalamazoo, MI) to improve CTL activation by recombinant adenovirus. The data show that coinjection of Gelfoam with type 5 adenovirus recombinant for prostate-specific Ag (Ad5-PSA) enhanced CTL activation. Ad5-PSA priming in Gelfoam also abrogated the inhibitory effects of adenoviral immunity on CTL activation in mice naive to PSA but immune to adenovirus. Finally, Gelfoam enhanced immunization in a self-Ag model using type 5 adenovirus recombinant for membrane-bound OVA (Ad5-mOVA) in rat insulin promoter (RIP)-mOVA-transgenic mice. Thus, Gelfoam enhances CTL activation by recombinant viral vectors in a setting where preformed Ab to the virus is present and also in a tolerant self-Ag model.     

GDNF重组腺病毒的构建及促进多巴胺能神经元存活的研究

利用体内同源重组原理,构建了能介导ＧＤＮＦ基因转移和表达的复制缺陷型重组腺病毒ＡｄＣＭＶｇｄｎｆ,其中ＧＤＮＦｃＤＮＡ插入腺病毒基因组的Ｅ１区并由ＣＭＶ启动子控制在人２９３细胞内通过同源重组包装生成重组腺病毒后,用形态学方法、病毒ＤＮＡ酶切分析、ＰＣＲ和ＲＴ－ＰＣＲ等方法进行鉴定正确．经测定病毒滴度达到１０１０ｐｆｕ／ｍｌ．用免疫沉淀方法从重组腺病毒感染的２９３细胞及其培养基上清中均检测到大量ＧＤＮＦ蛋白．用重组腺病毒直接感染或者用其条件培养基处理,分别使胚胎大鼠中脑原代多巴胺能神经元的数目增加８８．２％和９６．４％,明显增加多巴胺能神经元存活,对帕金森氏病基因治疗具有重要意义     

分泌睫状神经营养因子腺病毒载体的构建及小量复制病毒增强其分泌表达的研究

目的：探讨复制型腺病毒能否增强增殖缺陷型腺病毒Ad5-hCNTF所携带外源基因的表达分泌。方法：亚克隆获得分泌型睫状神经营养因子的基因（ciliary neurotrophic factor）,然后将此基因插入到穿梭质粒pshuttle。pshuttle-hCNTF经pme1酶切后,CIAP去磷酸化,利用Ad-EASY腺病毒制备系统,将其与腺病毒骨架质粒pAdEasy-1共同转化大肠杆菌BJ5183,通过同源重组,筛选出含目的基因的重组型腺病毒质粒的菌株,获得大量该质粒后转染病毒包装细胞AD-293,成功包装出一种血清5型增殖缺陷型腺病毒Ad5-hCNTF。结果：经PCR鉴定该病毒含有该基因片断,Western blotting证实该病毒感染细胞后能表达CNTF蛋白。采用ELISA法检测培养液证实感染细胞能高水平地分泌CNTF。结论：体外实验表明在不同滴度的复制型腺病毒Ad5-E1＋E3＋的带动下,该病毒感染细胞后分泌表达目的蛋白的水平显著提高,为今后应用Ad作为基因治疗的载体提供实验证据。     

A novel vector for a rapid generation of fiber-mutant adenovirus based on one step ligation and quick screening of positive clones

The generation of fiber-modified adenoviral vector has proven difficult. In the paper, we developed a new system for rapid construction of fiber-modified adenoviral vector containing foreign peptides in the HI loop or C-terminal of the fiber knob. The new system was established through the following processes. First, a unique BamHI mutation was made in the genome of Ad5 without causing amino acid change. Second, two unique restriction enzymes BamHI and SfuI, both with sticky end, were introduced in the HI loop or C-terminal of Ad5 fiber knob. Third, a lacza expression cassette was placed between BamHI and SfuI sites for a quick identification of positive cloning based on white-blue color screening. This system allows generation of recombinant adenoviral vector by a single step, in vitro ligation followed by quick white-color positive clone screening. To prove the principle of the method, Ad5HI-RGD by modifying HI-loop of the fiber knob with RGD motif and Ad5Cter-PK7 by modifying C-terminal of the knob with poly-lysine (pK7) were successfully generated in vitro. Ad5 with a knob modified in the HI loop of the fiber with Tat-PTD, NGR or SIKVAV peptide were also successfully developed. The transduction of the modified viruses for Hela, U87 MG and MDA-MB-231 cells was investigated in vitro compared with unmodified Ad5. In conclusion, the new vector system allows for a rapid generation of fiber-mutant adenovirus and provides useful tool for gene function analysis and cancer gene therapy.     

CD/TK单、双自杀基因重组腺病毒的制备及初步应用

为制备表达大肠杆菌胞嘧啶脱氨酶 (cytosinedeaminase ,CD)和单纯疱疹病毒 1 胸苷激酶(herpessimplexvirustype 1thymidinekinase ,TK)双自杀基因的重组腺病毒载体 ,为再狭窄基因治疗的应用奠定基础 ,首先构建了含单、双自杀基因的腺病毒穿梭载体 ,细菌内同源重组法获得重组腺病毒质粒 .脂质体介导下转染 2 93细胞进行包装并大量扩增得到Ad TK、Ad CD、Ad TK CD、Ad LacZ 4种重组腺病毒 .氯化铯 (CsCl)梯度离心法纯化后利用报告基因绿色荧光蛋白 (GFP)测定病毒滴度 ,可达 10 9pfu ml .PCR和Western印迹法对外源基因进行鉴定 ,证明单、双自杀基因均已整合入腺病毒基因组并表达 .重组腺病毒感染血管平滑肌细胞后 ,用MTT法比较了单、双自杀基因的杀伤作用 ,发现在感染复数≤ 2 0时 ,双自杀基因对细胞的抑制作用明显高于单基因 .成功地构建腺病毒双自杀基因共表达载体 ,为进一步的体内外实验奠定了基础 .     

Adenoviral gene transfer of eNOS: high-level expression in ex vivo expanded marrow stromal cells

Endothelial nitric oxide synthase (eNOS) is an attractive target for cardiovascular gene therapy. Marrow stromal cells (MSCs), also known as mesenchymal stem cells, hold great promise for use in adult stem cell-based cell and gene therapy. To determine the feasibility of adenoviral-mediated eNOS gene transfer into ex vivo expanded MSCs, rat MSCs (rMSCs) were isolated, expanded ex vivo, and transduced with Ad5RSVeNOS, an adenoviral vector containing the eNOS gene under the control of the Rous sarcoma virus promoter. The presence of eNOS protein in Ad5RSVeNOS-transduced rMSCs was confirmed by immunohistochemical and Western blot analysis. Transduction efficiency was dose dependent, and eNOS transgene expression in rMSCs persisted for =" BORDER="0">21 days in culture. The rMSCs retained multipotential differentiation capability after adenoviral-mediated eNOS gene transfer. Furthermore, intracavernosal injection of Ad5RSVeNOS-transduced rMSCs increased the expression of eNOS in the corpus cavernosum, and stem cells were identified within corporal sinusoids. These findings demonstrate that replication-deficient recombinant adenovirus can be used to engineer ex vivo expanded rMSCs and that high-level eNOS transgene expression can be achieved, pointing out the clinical potential of using this novel adult stem cell-based gene therapy method for the treatment of cardiovascular diseases. adenoviral vector; nitric oxide; gene expression; differentiation; gene therapy     

Dysregulation of CREB binding protein triggers thrombin-induced proliferation of vascular smooth muscle cells

Thrombin is a potent mitogen for vascular smooth muscle cells (VSMCs). CBP has been regarded as a potential therapeutic target on the basis of its ability to affect cell growth. Therefore we hypothesized that CBP mediates thrombin-induced proliferation of VSMCs. We constructed recombinant adenoviral vector that expresses four short hairpin RNA (shRNA) targeting rat CBP mRNA (CBP-shRNA/Ad). VSMCs were infected with CBP-shRNA/Ad and treated with thrombin. CBP level were analyzed by quantitative real-time PCR and Western blot. To evaluate VSMC proliferation, the cell cycle and DNA synthesis were analyzed by flow cytometry and (3)H-thymidine incorporation, respectively. CBP-shRNA/Ad infection inhibited thrombin-induced CBP expression in a dose-dependent manner concomitant with a decrease in the percentage of cells in the S phase and in DNA synthesis. These findings suggest that CBP plays a pivotal role in the S phase progression of VSMCs.     

表达双功能融合蛋白（sCAR-EGF）腺病毒载体的构建及其活性检测

为了提高腺病毒载体用于基因治疗的靶向性,采用PCR和体外连接的方法构建了柯萨奇病毒-腺病毒受体(Coxsackievirus-AdenovirusReceptor)胞外段sCAR和表皮生长因子(Epidermalgrowthfactor)EGF融合基因,然后将此融合基因插入穿梭质粒pDC315。利用Ad-MAX腺病毒系统,将重组质粒pDC315-sCAR-EGF与腺病毒骨架质粒pBHGloxΔE13cre共同转染AD-293细胞,成功包装出一种复制缺陷型腺病毒Ad5-CMV-sCAR-EGF。经PCR鉴定该病毒含有sCAR-EGF融合基因片段,Westernblotting证实该病毒能表达sCAR-EGF融合蛋白。体外试验证实该病毒感染细胞所产生的融合蛋白能够引导携带报告基因的腺病毒Ad5-CMV-luc高水平感染肿瘤细胞,为高水平表达EGFR的肿瘤的靶向性基因治疗提供了新的手段。     

Replication properties of human adenovirus in vivo and in cultures of primary cells from different animal species

Oncolytic adenoviruses have emerged as a promising approach for the treatment of tumors resistant to other treatment modalities. However, preclinical safety studies are hampered by the lack of a permissive nonhuman host. Screening of a panel of primary cell cultures from seven different animal species revealed that porcine cells support productive replication of human adenovirus type 5 (Ad5) nearly as efficiently as human A549 cells, while release of infectious virus by cells from other animal species tested was diminished by several orders of magnitude. Restriction of productive Ad5 replication in rodent and rabbit cells seems to act primarily at a postentry step. Replication efficiency of adenoviral vectors harboring different E1 deletions or mutations in porcine cells was similar to that in A549 cells. Side-by-side comparison of the viral load kinetics in blood of swine and mice injected with Ad5 or a replication-deficient adenoviral vector failed to provide clear evidence for virus replication in mice. In contrast, evidence suggests that adenovirus replication occurs in swine, since adenoviral late gene expression produced a 13.5-fold increase in viral load in an individual swine from day 3 to day 7 and 100-fold increase in viral DNA levels in the Ad5-infected swine compared to the animal receiving a replication-deficient adenovirus. Lung histology of Ad5-infected swine revealed a severe interstitial pneumonia. Although the results in swine are based on a small number of animals and need to be confirmed, our data strongly suggest that infection of swine with human adenovirus or oncolytic adenoviral vectors is a more appropriate animal model to study adenoviral pathogenicity or pharmacodynamic and toxicity profiles of adenoviral vectors than infection of mice.     

Prevalence and quantitation of species C adenovirus DNA in human mucosal lymphocytes

The common species C adenoviruses (serotypes Ad1, Ad2, Ad5, and Ad6) infect more than 80% of the human population early in life. Following primary infection, the virus can establish an asymptomatic persistent infection in which infectious virions are shed in feces for several years. The probable source of persistent virus is mucosa-associated lymphoid tissue, although the molecular details of persistence or latency of adenovirus are currently unknown. In this study, a sensitive real-time PCR assay was developed to quantitate species C adenovirus DNA in human tissues removed for routine tonsillectomy or adenoidectomy. Using this assay, species C DNA was detected in Ficoll-purified lymphocytes from 33 of 42 tissue specimens tested (79%). The levels varied from fewer than 10 to greater than 2 x 10(6) copies of the adenovirus genome/10(7) cells, depending on the donor. DNA from serotypes Ad1, Ad2, and Ad5 was detected, while the rarer serotype Ad6 was not. When analyzed as a function of donor age, the highest levels of adenovirus genomes were found among the youngest donors. Antibody-coated magnetic beads were used to purify lymphocytes into subpopulations and determine whether viral DNA could be enriched within any purified subpopulations. Separation of T cells (CD4/8- expressing and/or CD3-expressing cells) enriched viral DNA in each of nine donors tested. In contrast, B-cell purification (CD19-expressing cells) invariably depleted or eliminated viral DNA. Despite the frequent finding of significant quantities of adenovirus DNA in tonsil and adenoid tissues, infectious virus was rarely present, as measured by coculture with permissive cells. These findings suggest that human mucosal T lymphocytes may harbor species C adenoviruses in a quiescent, perhaps latent form.     

Generation and Immunity Testing of a Recombinant Adenovirus Expressing NcSRS2-NcGRA7 Fusion Protein of Bovine Neospora caninum

Neospora caninum is the etiologic agent of bovine neosporosis, which affects the reproductive performance of cattle worldwide. The transmembrane protein, NcSRS2, and dense-granule protein, NcGRA7, were identified as protective antigens based on their ability to induce significant protective immune responses in murine neosporosis models. In the current study, NcSRS2 and NcGRA7 genes were spliced by overlap-extension PCR in a recombinant adenovirus termed Ad5-NcSRS2-NcGRA 7, expressing the NcSRS2-NcGRA7 gene, and the efficacy was evaluated in mice. The results showed that the titer of the recombinant adenovirus was 10⁹TCID₅₀/ml. Three weeks post-boost immunization (w.p.b.i.), the IgG antibody titer in sera was as high as 1:4,096. IFN-γ and IL-4 levels were significantly different from the control group (P<0.01). This research established a solid foundation for the development of a recombinant adenovirus vaccine against bovine N. caninum.