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D T Curiel

Publications and source records attributed to D T Curiel.

At least 199 records · Page 11Linked to original sources
PubMed1997

Adenoviral/retroviral vector chimeras: a novel strategy to achieve high-efficiency stable transduction in vivo.

Gene therapy to correct defective genes requires efficient gene delivery and long-term gene expression. Realization of both goals with available vector systems has so far not been achieved. As a novel approach to solve this problem, we have developed a chimeric viral vector system that exploits favorable aspects of both adenoviral and retroviral vectors. In this schema, adenoviral vectors induce target cells to function as transient retroviral producer cells in vivo. The progeny retroviral vector particles can then effectively achieve stable transduction of neighboring cells. In this system, the nonintegrative adenoviral vector is rendered functionally integrative via the intermediate generation of an induced retroviral producer cell. Such chimeric vectors may now allow realization of the requisite goals for specific gene therapy applications.

Adenovirus Infections, Human↗
PubMed1997

Pancreatic carcinoma cell killing via adenoviral mediated delivery of the herpes simplex virus thymidine kinase gene.

OBJECTIVE: Use of adenoviral mediated delivery of the herpes simplex virus thymidine kinase (HSV-TK) gene as a gene therapy strategy for carcinoma of the pancreas. SUMMARY BACKGROUND DATA: Expression of HSV-TK selectively sensitizes cells to the nucleoside analog ganciclovir (GCV). This strategy has been used to treat other compartmentalized tumor models. Therefore, the containment of pancreatic carcinoma makes it amenable to this gene therapy approach. METHODS: A recombinant adenoviral vector encoding the HSV-TK gene was used to induce GCV sensitivity and test the potential bystander effect in established pancreatic carcinoma cell lines and patient-derived tumor material. Additionally, Balb/C nude mice were injected intraperitoneally with human pancreatic carcinoma cells and treated with GCV (50 mg/kg per day) for 14 days. RESULTS: Expression of the HSV-TK gene elicited a significant bystander effect in the presence of GCV. Pancreatic tumor cells injected intraperitoneally into nude mice resulted in significant tumor formation. Treatment of animals with AdCMVHSV/HSV-TK and GCV induced a dramatic decrease in overall tumor burden for up to 8 weeks post-GCV treatment. CONCLUSIONS: Pancreatic carcinoma cells are highly susceptible to transduction with recombinant adenoviral vector and elicit a potent bystander effect on neighboring tumor cells. Additionally, in vivo treatment of tumor-bearing animals results in dramatic reduction of overall tumor burden, thus providing the rationale for molecular chemotherapy of pancreatic carcinoma.

Adenoviridae↗
PubMed1997

Localization of iodine-125-mIP-Des-Met14-bombesin (7-13)NH2 in ovarian carcinoma induced to express the gastrin releasing peptide receptor by adenoviral vector-mediated gene transfer.

UNLABELLED: The gastrin releasing peptide receptor (GRPr) has a high affinity for the 14 amino acid bombesin peptide. For this analysis, [125I]-Tyr4-bombesin was compared with [125I]-mIP-bombesin (a seven amino acid bombesin analog) for in vitro binding and internalization into tumor cells and for tumor localization in vivo. Also, a recombinant adenoviral vector (AdCMVGRPr) was used for gene transfer to induce the expression of GRPr in human ovarian cancer cells for binding and tumor localization with these radiolabeled peptides. METHODS: [125I]-mIP-bombesin was synthesized and compared with [125I]-Tyr4-bombesin in internalization assays using BNR-11 cells (mouse fibroblast cells stably transfected with GRPr) over a 24-hr period. In vitro binding assays used BNR-11, and A427, HeLa and SKOV3.ip1 human cancer cells, which were either uninfected or infected with AdCMVGRPr. Biodistribution studies were performed in normal BALB/c mice and in athymic nude mice bearing orthotopic SKOV3.ip1 ovarian cancer tumors. The SKOV3.ip1 tumors were induced to express GRPr with the AdCMVGRPr adenoviral vector. RESULTS: Internalization assays showed that [125I]-Tyr4-bombesin was rapidly internalized and catabolized at 37 degrees C with approximately 10% of the radioactivity remaining intracellularly at 4 hr, compared with approximately 30% with [125I]-mIP-bombesin. HeLa, A427 and SKOV3.ip1 cells were all induced to express levels of GRPr that were higher than those seen with the positive control BNR-11 cells. Normal mice showed a lower level of radioactivity in both the blood and thyroid for [125I]-mIP-bombesin [0.26% +/- 0.10% injected dose per gram (ID/g) and 0.24% +/- 0.05% ID] than for [125I]-Tyr4-bombesin (3.5% +/- 1.6% ID/g and 5.2% +/- 4.4% ID) at 4 hr postinjection. Mice bearing intraperitoneal (i.p.) SKOV3.ip1 tumors and given AdCMVGRPr i.p. 5 days after tumor cell inoculation followed by [125I]-mIP-bombesin i.p. at day 7 showed 16.5% +/- 4.8% ID/g in tumor compared with 5.9% +/- 3.0% ID/g with [125I]-Tyr4-bombesin at 4 hr postinjection. Tumor bearing mice given saline or a control adenovirus expressing the beta-galactosidase (LacZ) gene showed significantly lower tumor uptake values of both bombesin peptides. CONCLUSION: Internalization assays showed that [125I]-mIP-bombesin has favorable characteristics compared with [125I]-Tyr4-bombesin with regards to cellular internalization and retention. The results demonstrate successful in vitro and in vivo transduction of human tumor cells with a recombinant adenoviral vector-expressing GRPr. Additionally, tumors transduced in vivo to express GRPr demonstrated significantly greater localization of [125I]-mIP-bombesin when compared with [125I]-Tyr4-bombesin.

Adenoviridae↗
PubMed1997

Adenovirus-mediated delivery of p16 to p16-deficient human bladder cancer cells confers chemoresistance to cisplatin and paclitaxel.

We have previously established the efficacy of adenoviral gene delivery vectors for the treatment of bladder carcinoma in vivo. In the present work, we developed a gene therapy strategy for bladder cancer based on the replacement of the tumor suppressor p16, which is known to be mutated or deleted in a variety of human tumors, including those derived from the bladder. Previous reports have demonstrated that reconstitution of p16 has marked effects on the proliferative capacity of tumor cell lines both in vitro and in vivo, and that p16 expression causes resistance to some chemotherapeutic agents. In the present study, we describe the construction of the recombinant adenovirus Adp16, expressing the p16 gene, to evaluate the effects of transient p16 replacement in the context of bladder carcinoma. To identify candidate target cell lines, we screened a panel of bladder cancer cell lines for p16 and retinoblastoma (RB) protein expression. We demonstrate that Adp16 can mediate high-efficiency p16 replacement to the p16-negative cell lines EJ and UMUC-3. In addition, the reconstitution of p16 to the highly transducible p16-negative, RB-positive bladder cancer cell line EJ caused a profound inhibition of cell proliferation mediated by arrest in the G1 phase of the cell cycle. In contrast, the p16-positive, RB-negative cell line J82 was unaffected by this treatment. However, when adenovirally mediated p16 replacement was combined with the chemotherapeutics cisplatin and paclitaxel, a marked chemoresistance was observed in genetically corrected cells. This work has implications for future gene therapy strategies based on p16 replacement.

Adenoviridae↗
PubMed1997

Adenoviral-mediated delivery of gastrin-releasing peptide receptor results in specific tumor localization of a bombesin analogue in vivo.

Radioimmunotherapy is hindered by a variety of factors linked to the utilization of monoclonal antibodies. These limitations include restricted tumor penetration as well as low levels of intratumoral antigen expression. To address the latter problem, we used a gene therapy approach to induce tumor cells to express enhanced levels of receptor with high binding affinity for a radiolabeled peptide. In this regard, a radiolabeled bombesin analogue was used in conjunction with a recombinant adenoviral vector encoding the murine gastrin-releasing peptide receptor (mGRPr). A panel of human carcinoma cell lines was infected in vitro with the recombinant adenoviral vector encoding the mGRPr vector to examine the induced binding of a 125I-labeled bombesin peptide. All cell lines examined displayed high levels of induced peptide binding, with approximately 60-80% of the radioactivity bound to the cells, in a live-cell binding assay. The human ovarian carcinoma cell line SKOV3.ip1 was chosen for in vivo analysis of radiolabeled bombesin analogue tumor localization in biodistribution and pharmacokinetic studies in athymic nude mice. Genetic induction of mGRPr in vivo resulted in selective tumor uptake of the radiolabeled peptide and high tumor:blood ratios. The biodistribution results compared favorably to those obtained with 131I-labeled e21 anti-erbB-2 monoclonal antibody in animals bearing i.p. SKOV3.ip1 tumors that endogenously express erbB-2. Thus, a novel method to combine gene transfer and radioimmunotherapy may result in augmented tumor cell targeting of radiopharmaceuticals.

Adenoviridae↗
PubMed1996

Molecular conjugate-mediated gene transfer into isolated human kidneys.

Advances in systemic immunosuppressive therapy for solid organ transplantation have done little to decrease the percentage of allografts that eventually will develop chronic rejection. However, one of the promises of modern molecular biology includes the ability to introduce new genetic information into mammalian hosts. The ability to deliver genes and control their expression in the adult kidney has been described in appropriate animal models. Consequently, gene transfer technology represents a realistic therapeutic approach to modify the allogeneic kidney before engraftment in an effort to decrease the incidence of posttransplant dysfunction. To bridge the gap between animal studies and the clinical application of this technology, we report the first genetic transfection of isolated human kidneys under conditions of organ preservation. Polymerase chain reaction, reversed transcription polymerase chain reaction, and in situ hybridization techniques demonstrated that an adenovirus-polylysine-deoxyribonucleic acid (DNA) complex can be used to insert a complementary DNA expression vector encoding beta-galactosidase into the intact human kidney. Immunohistochemical and in situ enzymatic analyses determined further that gene delivery and expression were localized in proximal tubular epithelial cells. Consequently, targeting of genes to perturb mediators of the local inflammatory response may represent a rational therapeutic interventional strategy in chronic rejection of the kidney.

Adenoviridae↗
PubMed1996

Targeted gene transfer to human hematopoietic progenitor cell lines through the c-kit receptor.

In this report, we describe a novel gene therapy approach for hematopoietic stem/progenitor cells using a specific receptor-mediated gene transfection procedure to target c-kit+ cell lines. The vector consists of plasmid DNA containing a luciferase reporter gene that is condensed by electrostatic forces with polylysine (PL) covalently linked to streptavidin (binds biotinylated ligand) and PL covalently linked to adenovirus (AD; to achieve endosomal lysis) with the final addition of biotinylated steel factor (SLF-biotin). Targeted transfection of growth factor-dependent hematopoietic progenitor cell lines that express c-kit showed specific luciferase gene expression over cell lines that did not express c-kit. This effect was dependent on the dose of SLF-biotin and was competed by excess SLF or with monoclonal antibodies that recognize c-kit and block the binding of SLF to its receptor. Maximum transfection efficiency (> 90%) requires a 2-hour incubation period of the vector with the cells, and maximum gene expression occurred 30 hours later. Removal of the endosomalytic agent, AD, from the vector resulted in the loss of gene expression. Vector targeting was versatile and could be changed by the addition of other biotinylated ligands. In principle, this vector should be broadly applicable to deliver genes to hematopoietic stem/progenitor cells in vitro and in vivo.

Adenoviridae↗
PubMed1996

Adenoviral-mediated delivery of herpes simplex virus thymidine kinase results in tumor reduction and prolonged survival in a SCID mouse model of human ovarian carcinoma.

The herpes simplex virus thymidine kinase gene is the most widely utilized toxin for selective killing of carcinoma cells. Expression of the viral thymidine kinase gene renders cells sensitive to the toxic effects of nucleoside analogs such as ganciclovir. An advantage of this system is the "bystander effect" whereby thymidine kinase transduced tumor cells elicit a toxic effect on surrounding nontransduced tumor cells. Ovarian carcinoma appears to be an ideal candidate for gene therapy as the majority of women present with advanced stage disease, have poor prognosis for long-term survival and have the disease confined within the peritoneal cavity. Therefore the utility of an adenoviral vector to elicit an in vitro bystander effect in ovarian carcinoma cells and the therapeutic efficacy of such a system in vivo was undertaken. Immunocompetent animals were utilized to determine the maximum dose of adenovirus that could be administered without any undesirable side effects and that preimmunization had no effects on subsequent challenge. SCID mice were orthotopically transplanted with human ovarian carcinoma cells and, after establishment of tumor, given a recombinant adenovirus expressing either the herpes simplex virus thymidine kinase or the Escherichia coli beta-galactosidase gene. Half the animals from each viral group were treated with either a ganciclovir regiment (50 mg/kg daily for 14 days) or an equal volume of serum-free media. A subset of mice were killed following drug treatment and analyzed for tumor reduction. The remaining animals were followed daily for survival. The animals treated with the recombinant adenovirus expressing the herpes simplex virus thymidine kinase gene and ganciclovir had significant reduction in overall tumor burden and demonstrated statistically significant prolongation in overall survival.

Adenoviridae↗
PubMed1996

Targeted gene delivery by tropism-modified adenoviral vectors.

The utility of adenoviral vectors for gene therapy is currently limited due, in part, to the widespread distribution of the cellular receptor for the adenovirus fiber that precludes the targeting of specific cell types. In order to develop a targeted adenovirus, it is therefore necessary both to ablate endogenous viral tropism and to introduce novel tropism. We hypothesized that these two goals could be achieved by employing a neutralizing anti-fiber antibody, or antibody fragment, chemically conjugated to a cell-specific ligand. To test this concept, we chose to target the folate receptor, which is overexpressed on the surface of a variety of malignant cells. Therefore, we conjugated folate to the neutralizing Fab fragment of an anti-fiber monoclonal antibody. This Fab-folate conjugate was complexed with an adenoviral vector carrying the luciferase reporter gene and was shown to redirect adenoviral infection of target cells via the folate receptor at a high efficiency. Furthermore, when complexed with an adenoviral vector carrying the gene for herpes simplex virus thymidine kinase, the Fab-folate conjugate mediated the specific killing of cells that overexpress the folate receptor. This work thus represents the first demonstration of the retargeting of a recombinant adenoviral vector via a non-adenoviral cellular receptor.

Adenoviridae↗
PubMed1996

Gene therapy strategies for novel cancer therapeutics.

The context of this review highlights current strategies being employed in gene therapy for neoplastic diseases. Three main approaches, mutation compensation, molecular chemotherapy, and genetic immunopotentiation, have been undertaken. Mutation compensation relies on strategies to ablate activated oncogenes or augment tumor-suppressor gene expression. Molecular chemotherapy uses delivery of a toxin gene to tumor cells for eradication. Genetic immunopotentiation augments the host immune response against tumor-associated antigens via delivery of immune stimulatory molecules or delivery of foreign genes. Rapid implementation of a variety of gene therapy strategies have been undertaken for human clinical trials.

Genes, Tumor Suppressor↗
PubMed1996

Generation of recombinant adenovirus vectors with modified fibers for altering viral tropism.

To expand the utility of recombinant adenovirus vectors for gene therapy applications, methods to alter native viral tropism to achieve cell-specific transduction would be beneficial. To this end, we are pursuing genetic methods to alter the cell recognition domain of the adenovirus fiber. To incorporate these modified fibers into mature virions, we have developed a method based on homologous DNA recombination between two plasmids. A fiber-deleted, propagation-defective rescue plasmid has been designed for recombination with a shuttle plasmid encoding a variant fiber gene. Recombination between the two plasmids results in the derivation of recombinant viruses containing the variant fiber gene. To establish the utility of this method, we constructed a recombinant adenovirus containing a fiber gene with a silent mutation. In addition, we generated an adenovirus vector containing chimeric fibers composed of the tail and shaft domains of adenovirus serotype 5 and the knob domain of serotype 3. This modification was shown to alter the receptor recognition profile of the virus containing the fiber chimera. Thus, this two-plasmid system allows for the generation of adenovirus vectors containing variant fibers. This method provides a rapid and facile means of generating fiber-modified recombinant adenoviruses. In addition, it should be possible to use this system in the development of adenovirus vectors with modified tropism to allow cell-specific targeting.

Adenoviridae↗
PubMed1996

Gene therapy approaches for inherited and acquired lung diseases.

Gene therapy is the treatment of any disorder or pathophysiologic state based upon the transfer of genetic information. The lung represents a major target of gene therapy for the treatment of genetic disorders such as cystic fibrosis and alpha 1-antitrypsin deficiency. Other diseases are also being targeted, including pulmonary inflammation, surfactant deficiency, pulmonary hypertension, lung cancer, and malignant mesothelioma. This review will examine some general concepts regarding gene transfer and gene therapy, provide an overview of the current vectors being developed to achieve safe and efficient gene transfer, and summarize the ongoing work to apply this new technology to the treatment of both inherited and acquired pulmonary diseases. Although tremendous progress has been made in the ability to successfully transfer genes to cells, there are several unresolved problems limiting the clinical application of this technology to human pulmonary disease. However, as vector technology evolves, gene therapy may become a reality for a number of lung diseases.

Animals↗
PubMed1996

erbB-2 knockout employing an intracellular single-chain antibody (sFv) accomplishes specific toxicity in erbB-2-expressing lung cancer cells.

erbB-2 is known to be overexpressed in several human malignancies including lung cancer. Because of its role in neoplastic transformation as well as its association with poor prognosis, this oncogene has been targeted through various anti-cancer methodologies. In this regard, we have recently demonstrated that erbB-2-overexpressing ovarian tumor cell lines transfected with an endoplasmic reticulum form of an anti-erbB-2 single-chain antibody undergo a specific cytotoxicity through the induction of apoptosis. Since certain forms of lung cancer are also associated with overexpression of erbB-2, we evaluated the use of this novel therapeutic in this context. For these studies, several human lung adenocarcinoma cell lines were stably and transiently transfected with the anti-erbB-2 sFv gene. We demonstrate here that the anti-erbB-2 sFv can cause specific cytotoxicity in lung cancer cells. As a first step toward clinical translation of this strategy, we constructed a replication-deficient recombinant adenoviral vector expressing the anti-erbB-2 sFv construct. We further demonstrate that our anti-erbB-2 sFv-encoding adenoviral vector can accomplish high levels of cytotoxicity in lung cancer cells. Based on these results, it is proposed that this strategy of oncoprotein ablation may have use in the treatment of some forms of human lung cancer.

Adenoviridae↗
PubMed1996

Efficient gene transfer to dispersed human pancreatic islet cells in vitro using adenovirus-polylysine/DNA complexes or polycationic liposomes.

The establishment of gene delivery systems that result in efficient transfection of the pancreatic beta-cells may generate an important tool for the study of IDDM and may also represent one critical step toward a clinical application of gene transfer for the prevention or early treatment of the disease. Using the reporter gene vectors pCAT and pCMV beta-gal, we have investigated the efficiency of transfection mediated by calcium phosphate precipitation, the monocationic liposome Lipofectin, the polycationic liposome Lipofectamine, and adenovirus-polylysine (AdpL) DNA complexes in human, mouse, rat, and fetal porcine islet cells. In all species studied, calcium phosphate-mediated transfection resulted in lower chloramphenicol acetyl transferase (CAT) activities than the other methods. Intact human, mouse, and rat islets were poorly transfected by Lipofectin, Lipofectamine, and AdpL. When dispersed by trypsin treatment, however, human, mouse, rat, and fetal pig islect cells were efficiently transfected by Lipofectamine. Moreover, transfection of dispersed human and mouse islet cells using AdpL, also resulted in high CAT activities. The percentage of cells staining positively for beta-galactosidase after transfection with Lipofectamine was 49% for mouse, 56% for rat, and 57% for dispersed human islet cells. Transfection of human islet cells using AdpL, however, yielded 70% beta-gal-positive cells. Fluorescence-activated cell sorting-purified rat islet alpha- and beta-cells were transfected with similar efficiency using Lipofectamine. CAT expression in human islet cells transfected with either Lipofectamine or AdpL reached a peak value after 5-7 days, followed by a gradual decline. It is concluded that transfection with AdpL or Lipofectamine are both efficient means to achieve transient expression of gene constructs in human and mouse islet cells, while for rat and fetal porcine islet cells, Lipofectamine is the most efficient of the agents investigated in this study.

Analysis of Variance↗
PubMed1996

Polynucleotide-mediated immunization therapy of cancer.

The novel observations that intramuscular injection of plasmid DNA preparations could result in myocyte gene expression and induce immune responses to encoded immunogens has generated intense interest in the form of gene therapy. This phenomena can occur with both DNA and RNA reagents, and can be used in immune protection (vaccine) or therapy strategies. Immunization with DNA plasmids has generated protective immunity to a wide variety of pathogens and tumor cells in murine animal models. Immune response has occurred in a broad range of animal species following intramuscular injection of plasmid DNA encoding various immunogens as well as following other routes of administration (intravenous, intradermal, etc). The mechanisms responsible for induction of the immune response are as yet unclear, but responses include antibody production, T-cell proliferation, lymphokine release, generation of cytolytic T cells, and delayed hypersensitivity reactions. Plasmid DNA production and purification methods are relatively easy to standardize, and dual expressing plasmids allow incorporation of immune enhancement molecules or second immunogens. Plasmid DNA encoding nontransforming tumor-associated antigens are in development with a National Institutes of Health-approved protocol for carcinoembryonic antigen in colorectal cancer patients. Transforming tumor-associated antigens (eg, HER2/neu) may be approached with RNA or replicative RNA constructs for immunization. The efficacy of this immune approach will soon be examined in clinical trials in patients with cancer and the acquired immunodeficiency syndrome.

Animals↗
PubMed1996

Efficient delivery of triplex forming oligonucleotides to tumor cells by adenovirus-polylysine complexes.

Oligonucleotides (ODNs) show great promise in their ability to specifically inhibit single gene expression but must cross the cell membrane, escape the endosomal vesicle, and possibly traverse the nuclear membrane to arrive at their intracellular target molecules. In an attempt to improve the delivery of phosphodiester triplex forming ODNs to malignant cells, we have constructed adenovirus-polylysine (AdpL)-ODN complexes designed to take advantage of the receptor mediated endocytosis of adenoviruses to transfer the ODNs to the cell nucleus. Treatment of several different types of tumor cells in culture by AdpL-ODN complex resulted in superior uptake and persistence of the ODNs compared to both free ODN and cationic lipid-ODN complexes. Nuclear uptake peaks at 4 h and intact ODN persists in the nucleus with a half-life of 12 h. ODN concentrations of 20-70 microM are achieved at 24 h in all monolayer cell lines evaluated to date. ODNs are detected in 50-100% of the total cell population by immunohistochemistry with apparent uptake into vesicles and nuclear localization. Luciferase expression of a co-delivered reporter plasmid suggests that these ODNs are free in the nucleus. AdpL-ODN complexes will provide a valuable tool for delivering unmodified ODNs to the nucleus of malignant cells.

Adenoviruses, Human↗