Adenovirus-mediated gene transfer

The introduction of foreign genetic material into somatic cells in intact organisms is an important investigational technique that holds considerable promise as a therapeutic tool. Although successful gene transfer has been achieved by the use of both cell-mediated and direct techniques, most strategies have been limited either by constraints on the type, accessibility, and growth state of the target cell population, or by the low efficiency of genetic modification. Among the available vectors for somatic cell gene transfer, recombinant adenoviruses have several properties that make them particularly attractive for direct, in vivo introduction of foreign genes into adult animals and people. Simple techniques for the efficient generation and propagation of recombinant adenoviruses have been developed, and early studies employing recombinant adenoviral vectors demonstrate their potential for broad experimental and eventual clinical application. To exploit this potential properly, a number of important issues, including the efficiency of genetic modification of a targeted cell population, stability of foreign gene expression, effects of host immune response, and cell-type specific targeting of gene transfer, remain to be addressed.     

Adenovirus-mediated gene transfer in the ovine pituitary gland is associated with hypophysitis

Gene therapy for pituitary disease requires evaluation for safety as well as efficacy. We have reported results of adenovirus-mediated gene transfer using the sheep as a large animal model that allows longitudinal evaluation of hormone secretion and have confirmed high levels of transgene expression up to 7 days after direct stereotaxic injection into the pituitary gland. Here we report the results of detailed histological examination of the pituitary glands from animals injected with two recombinant adenoviruses expressing the beta-galactosidase marker gene, or with saline vehicle to control for the potential tissue-disruptive effect of the injection volume itself. Pituitaries injected with saline showed no evidence of inflammatory response apart from occasional minor foci of apoptosis. In all other respects they were indistinguishable from normal uninjected control pituitary glands. Glands injected with recombinant adenoviruses containing either the hCMV-beta-gal or the hPRL-beta-gal transgene, on the other hand, displayed variable degrees of inflammatory response, with periglandular fibrosis, lymphocytic infiltrate and venulitis in almost all cases. Focal necrosis and/or apoptosis was noted in six of nine cases. In summary, we have found evidence of severe inflammatory reaction within the first seven days of adenovirus injection, amounting to significant hypophysitis. The histological extent of this reaction has not previously been recognised by studies of the efficacy of gene transfer in rodents, and was underestimated by immunocytochemical studies of hormone and transgene expression. The findings emphasise the need for careful evaluation of the safety of endocrine gene therapy, and for caution with the dose of vector used.     

腺病毒介导性基因导入血管平滑肌细胞

目的 :探讨腺病毒介导性基因导入血管平滑肌细胞 ( SMC)的有效性。方法 :选用含有细菌 L ac Z基因的重组腺病毒及脂质体载体导入培养主动脉 SMC并用组织化学法定性定量检测基因表达的产物。结果 :腺病毒与 SMC接触几分钟就可使 SMC转染 ,2 h即可使 10 0 %的细胞受其转染并表达 L ac Z基因 ;基因表达的程度与病毒滴度呈剂量依赖关系 ;转染后 2 4h即可在 SMC中检出外源基因的表达 ,3～ 5 d达高峰 ;脂质体转导法仅可使不足 1%的 SMC表达外源基因 ;腺病毒介导性基因导入法约为脂质体转导法的 2 5 0倍。结论 :本研究获得的腺病毒介导性基因导入 SMC的多种参数 ,可为其未来的研究和治疗应用提供依据     

Adenovirus-mediated FasL gene transfer into human gastric carcinoma

AIM: To evaluate the possible value of FasL in gastric cancer gene therapy by investigating the effects of FasL expression on human gastric cancer cell line. METHODS: An adenoviral vector encoding the full-length human FasL cDNA was constructed and used to infect a human gastric cancer (SGC-7901) cell line. FasL expression was confirmed by X-gal staining, flow cytometric analysis and RT-PCR. The effect of FasL on cell proliferation was determined by clonogenic assay, cytotoxicity was detected by MTT assay, and cell viability was measured by trypan blue exclusion. The therapeutic efficiency of Ad-FasL in vivo was investigated with a xenograft tumor model in nude mice. RESULTS: SGC-7901 cells infected with Ad-FasL showed increased expression of FasL, resulting in significantly decreased cell growth and colony-forming activity when compared with control adenovirus-infected cells. The cytotoxicity of anti-Fas antibody (CH-11) in gastric cancer cells was stronger than that of ActD (91±8 vs60±5,P<0.01), and the cytotoxicity of Ad-FasL was stronger than that of CH-11 (60±5 vs50±2, P<0.05). In addition, G1-phase arrest (67.75±0.39 vs 58.03±2.16, P<0.05) and apoptosis were observed in Ad-FasL-infected SGC-7901 cells, and the growth of SGC-7901 xenografts in nude mice was retarded after intra-tumoral injection with Ad-FasL (54% vs 0%,P<0.0001). CONCLUSION: Infection of human gastric carcinoma cells with Ad-FasL induces apoptosis, indicating that this target gene might be of potential value in gene therapy for gastric cancer.     

Adenovirus-mediated p53 gene transfer sensitizes hepatocellular carcinoma cells to heavy-ion radiation

Background The purpose of this study was to investigate whether adenovirus-mediated p53 transfer could sensitize hepatocellular carcinoma to heavy-ion irradiation. Methods HepG2 cells were preexposed to a ¹²C⁶⁺ beam, and then infected with replication-deficient adenovirus recombinant vectors containing human wild-type p53 (AdCMV-p53) (¹²C⁶⁺ irradiation + AdCMV-p53 infection). The survival fraction was determined by clonogenic assay. The cell cycle, cell apoptosis, and p53 expression were monitored by flow cytometric analysis. Results p53 expression in ¹²C⁶⁺ irradiation + AdCMV-p53 infection groups was markedly higher than that in ¹²C⁶⁺ irradiation only groups (P < 0.05), suggesting that the preexposure to the ¹²C⁶⁺ beam promoted the expression of exogenous p53 in HepG2 cells infected with AdCMV-p53 only. The G₁-phase arrest and cell apoptosis in the ¹²C⁶⁺ irradiation + AdCMV-p53 infection groups were significantly more than those in the ¹²C⁶⁺ irradiated groups (P < 0.05). The survival fractions of the ¹²C⁶⁺ irradiation + AdCMV-p53 infection groups decreased by 30%–49% compared with those of the ¹²C⁶⁺ beam-irradiated only groups (P < 0.05). Conclusions Adenovirus-mediated p53 gene transfer can promote G₁-phase arrest and cell apoptosis, thus sensitizing hepatocellular carcinoma cells to heavy-ion irradiation.     

Adenovirus-mediated intralesional interferon-gamma gene transfer induces tumor regressions in cutaneous lymphomas

Primary cutaneous lymphomas have been successfully treated with interferons (IFNs), counterbalancing the T-helper 2 (Th2)-skewing state. We undertook a phase 1, open-label, dose-escalating trial of repeated intratumoral administration of TG1042 in patients with advanced primary cutaneous T-cell lymphomas (CTCLs) and multilesional cutaneous B-cell lymphomas (CBCLs). TG1042 is a third-generation, nonreplicating human adenovirus vector containing a human IFN-gamma cDNA insert. Nine patients (7 CTCL, 2 CBCL) were enrolled at the following TG1042 doses: 3 x 10(9), 3 x 10(10), and 3 x 10(11) total particles. Local clinical response was observed in 5 of 9 treated patients (3 patients with complete response [CR] and 2 patients with partial response [PR]). Out of these, 3 patients showed systemic CR with the clearance of other noninjected skin lesions. Clinical response lasted for a median of 3 months (range, 1-6 months). Adverse events were mostly of grades 1 and 2. Seven of 9 treated patients had a detectable TG1042-derived IFN-gamma message in injected lesions after the first treatment cycle. A TG1042-IFN-gamma message was also detectable after several treatment cycles. We demonstrate the induction of humoral immune response to lymphoma tumor-antigen se70-2 after treatment. Our study shows that intralesional injections of TG1042 are both safe and well tolerated.     

腺病毒介导高血压相关基因转移对兔颈动脉球囊损伤后新生内膜形成的抑制作用

目的 探讨腺病毒载体介导的新基因高血压相关基因(Hypertension-related gene,HRG-1)转移对兔颈总动脉球囊损伤后新生内膜形成的影响。方法 兔颈总动脉球囊损伤后,经血管腔内转染含有HRG-1的腺病毒载体(AdHRG-1)或含有绿色荧光蛋白报告基因的空载腺病毒载体(AdGFP),以生理盐水处理为对照。于术后3、7和28 d取材,分别进行外源基因表达检测、PCNA染色和定量组织形态学分析。结果 应用逆转录-聚合酶链反应和免疫组织化学方法分别证实了基因转移后3 d HRG-1在兔颈动脉壁内的表达;PCNA免疫组织化学染色显示,转染AdHRG-1后7 d兔颈动脉内膜和中膜PCNA阳性细胞指数较转染AdGFP组明显降低[(21.4±2.5)％对(45.6±3.8)％,(6.4±1.1)％对(17.8±1.9)％,P<0.05]。基因转移后28 d血管壁定量组织形态学分析显示,转染AdHRG-1组血管新生内膜面积及内膜面积与中膜面积比均显著低于转染AdGFP组[(0.13±0.03)mm2对(0.45±0.14)mm2,0.19±0.02对0.70±0.15,P<0.01],血管腔面积则显著增加[(0.88±0.07)mm2对(0.57±0.27)mm2,P<0.01],而转染AdGFP组与生理盐水处理组间无显著性差异。结论 以腺病毒为载体经血管腔内转染HRG-1可有效抑制球囊损伤后血管平滑肌细胞增殖和新生内膜形成。     

Adenovirus-mediated viral interleukin-10 gene transfer prevents concanavalin A-induced liver injury

Background and aimLiver injury is closely associated with immune inflammation. Lacking immunostimulatory functions, viral interleukin-10 (vIL-10), a cellular IL-10 homologue, has been an attractive molecule for immunomodulatory therapy. We aimed to reveal a protective effect of the gene transfer of an adenoviral vector encoding vIL-10 on liver injury induced by concanavalin A.MethodsC57BL/6J mice were intravenously injected with adenoviral vector encoding vIL-10 before concanavalin A challenge. Liver injury was assessed. Interferon-γ and interleukin-4 levels were measured by ELISA. The activation of splenic and hepatic immune cells was analysed using an MTT assay.ResultsAdenoviral vector encoding vIL-10 pretreatment significantly decreased concanavalin A-mediated elevations in serum alanine aminotransaminase and aspartate aminotransaminase activity, and necrotic area in liver tissues. The protective effect of adenoviral vector encoding vIL-10 was attributed to its inhibition of T cell activation, and production of interferon-γ and interleukin-4 by the immune cells. Recombinant mouse IL-10, a high homologous cytokine to vIL-10, effectively downregulated interferon-γ and interleukin-4 release by hepatic mononuclear cells.ConclusionAdenovirus vector-mediated vIL-10 gene transfer can prevent concanavalin A-induced hepatic injury, minimise pro-inflammatory cytokine release, and inhibit the activation of T lymphocytes.     

Targeting ischemic cardiac dysfunction through gene transfer

Ischemic cardiac injury is a complication of atherosclerosis, which remains a major contributor to morbidity and mortality throughout much of the world. Previous studies have documented apoptotic cardiomyocyte death in this setting; however, its functional contribution remains incompletely defined. We briefly review general mechanisms of apoptosis and then present evidence from interventional studies that suggests apoptotic cell death may indeed play an important role in the pathogenesis of ischemic injury. In some instances, the signaling pathways controlling both cardiomyocyte survival and function appear to converge, suggesting these pathways may represent particularly attractive targets for therapeutic intervention in ischemic heart disease. In this context, gene transfer provides both a powerful experimental tool for validating such targets for intervention, as well as an approach to therapy.     

Adenovirus-mediated gene transfer of insulin-like growth factor 1 stimulates proteoglycan synthesis in rabbit joints

OBJECTIVE: To examine the effect of insulin-like growth factor 1 (IGF-1) on the regulation of cartilage synthesis and other articular events in vivo. METHODS: A first-generation adenoviral vector expressing human IGF-1 (AdIGF-1) from the cytomegalovirus promoter was constructed. Particles of AdIGF-1 (5 x 10(9)) were injected through the patellar tendon into normal rabbit knee joints and rabbit knee joints with antigen-induced arthritis (AIA), with the same dose of a control adenoviral vector injected into the contralateral knees. Lavage fluids were obtained from rabbit knee joints on days 3 and 7 postinjection and used for analysis of IGF-1 expression, white blood cell infiltration, and cartilage breakdown. Cartilage chips from rabbit joints were used for assay of new proteoglycan synthesis, and tissues also were harvested from the dissected knees for histologic study. RESULTS: Intraarticular injection of AdIGF-1 resulted in a mean of 180.6 ng/ml of IGF-1 expression in the lavage fluid from rabbit joints. IGF-1 expression stimulated new proteoglycan synthesis in both naive and AIA rabbit knees, but had no significant chondroprotective or antiinflammatory effects. Histologic analysis showed that elevated levels of IGF-1 expression in both normal and arthritic knees had no adverse pathologic effects on synovium or adjacent muscles. CONCLUSION: Gene transfer of IGF-1 into rabbit knee joints promotes proteoglycan synthesis without significantly affecting inflammation or cartilage breakdown. In addition, no adverse effects following intraarticular IGF-1 gene delivery were observed. Thus, local gene transfer of IGF-1 to joints could serve as a therapeutic strategy to stimulate new matrix synthesis in both rheumatoid arthritis and osteoarthritis.     

Adenovirus-mediated gene delivery into neuronal precursors of the adult mouse brain.

Precursor cells found in the subventricular zone (SVZ) of the adult brain can undergo cell division and migrate long distances before differentiating into mature neurons. We have investigated the possibility of introducing genes stably into this population of cells. Replication-defective adenoviruses were injected into the SVZ of the lateral ventricle of adult mice. The adenoviruses carried a cDNA for the LacZ reporter or the human p75 neurotrophin receptor, for which species-specific antibodies are available. Injection of the viruses into the SVZ led to efficient labeling of neuronal precursors. Two months after viral injection, infected cells were detected in the olfactory bulb, a significant distance from the site of injection. Labeled periglomerular and granular neurons with extensive dendritic arborization were found in the olfactory bulb. These results demonstrate that foreign genes can be efficiently introduced into neuronal precursor cells. Furthermore, adenovirus-directed infection can lead to long-term stable gene expression in progenitor cells found in the adult central nervous system.     

Taurohyodeoxycholate- and tauroursodeoxycholate-induced hypercholeresis is augmented in bile duct ligated rats

BACKGROUND/AIMS: Taurohyodeoxycholate (THDCA) and tauroursodeoxycholate (TUDCA) induce more bile flow per molecule excreted compared to endogenous bile acids. The aim of this study is to determine if the hypercholeretic effect of tauroursodeoxycholate or taurohyodeoxycholate in normal and bile duct ligated (BDL) rats is due to increased ductal secretion. METHODS: Normal or BDL rats were infused with tauroursodeoxycholate or taurohyodeoxycholate and bile flow, bicarbonate, bile salt, cholesterol, and phospholipid secretion were measured. Cholangiocytes were stimulated with taurohyodeoxycholate or tauroursodeoxycholate, and secretin-stimulated secretion was measured. RESULTS: Taurohyodeoxycholate and tauroursodeoxycholate increased bile flow more in BDL than normal rats. Tauroursodeoxycholate increased bicarbonate secretion more in BDL compared to normal rats. Taurohyodeoxycholate when infused with taurocholate increased bile flow (but not phospholipid excretion) to a greater degree in BDL compared to normal rats. Taurohyodeoxycholate and tauroursodeoxycholate decreased secretin-stimulated cholangiocyte secretion. CONCLUSIONS: Consistent with a ductal origin for bile acid-induced hypercholeresis, taurohyodeoxycholate and tauroursodeoxycholate produced a greater hypercholeresis in BDL than normal rats. Tauroursodeoxycholate- (but not taurohyodeoxycholate-) stimulated hypercholeresis is associated with increased HCO(3)(-) secretion. Tauroursodeoxycholate increases biliary HCO(3)(-) secretion by a mechanism unrelated to secretin-stimulated cholangiocyte secretion. Taurohyodeoxycholate-induced hypercholeresis in BDL rats is unrelated to enhanced phospholipid excretion.     

Adenovirus-mediated gene transfer of superoxide dismutase and catalase decreases restenosis after balloon angioplasty

BACKGROUND: Reactive oxygen species (ROS) production increases after injury and potentially contributes to restenosis after angioplasty. We therefore evaluated the effect of adenovirus-mediated gene transfer (Ad) of superoxide dismutase (SOD) and catalase (CAT) on ROS production and restenosis after balloon angioplasty. METHODS: O(2)(-) and H(2)O(2 )production was quantified in cultured cells after incubation with either LPS or CuSO(4). Angioplasty and gene transfer were performed in rabbit atherosclerotic iliac arteries. One artery was injected with AdSOD and AdCAT, while the contralateral artery was injected with an adenovirus carrying no transgene, and served as control. RESULTS: ROS production was significantly decreased after adenovirus-mediated gene transfer of SOD and CAT as compared with control. Treated arteries showed less restenosis (32 +/- 27 vs. 63 +/- 19%, p = 0.003) and less constrictive remodeling (1.2 +/- 0.3 vs. 0.9 +/- 0.2, p = 0.02) than control arteries. Arteries injected with AdSOD and AdCAT showed better vasoreactivity to acetylcholine (11 +/- 4 vs. -1 +/- 6%, p < 0.05), lower collagen density (43 +/- 16 vs. 53 +/- 23%, p = 0.03), and lower inflammatory cell infiltration (22 +/- 6 vs. 36 +/- 11%, p = 0.04) than control arteries. CONCLUSIONS: Our data suggest that adenovirus-mediated gene transfer of SOD and CAT reduced oxidative stress, restenosis, collagen accumulation, and inflammation and improved endothelial function after angioplasty.     

Early return of augmented wave reflection impairs left ventricular relaxation in aged Fisher 344 rats

Left ventricular (LV) relaxation is influenced by vascular loads imposed on the heart. The current study investigated the influence of the timing and magnitude of arterial wave reflection on LV isovolumic pressure relaxation, with a specific focus on the aging process. Fisher 344 rats aged 6, 18, and 24months were anesthetized and thoracotomized. Arterial wave reflection was characterized by wave transit time (τ(w)) and wave reflection factor (R(f)) using the impulse response of the filtered aortic input impedance spectra. Indices of LV pressure relaxation included peak -dP(LV)/dt and the isovolumic relaxation time constant (τ(e)). The vascular dynamic condition in the rats was characterized by (1) a progressive increase in R(f) and decrease in τ(w) associated with age, especially at 24months; and (2) a decline in aortic compliance (C(m)). Changes in LV relaxation consisted of a fall in peak -dP(LV)/dt and a rise in LV τ(e) with age. Taking LV τ(e) as the dependent variable and arterial R(f) and τ(w) as the two independent variables, multiple linear regression was employed to fit the data. The correlation among the three parameters reached significance (τ(e) =11.885+5.350×R(f)-0.213×τ(w); r=0.5823, p<0.05). This finding indicated that as arterial τ(w) shortened and arterial R(f) was augmented with age, LV τ(e) became more prolonged and late pressure relaxation slowed. Thus, the heavy reflection intensity with early return of the pulse wave reflection might account for the age-related deterioration in LV isovolumic pressure decay.