High-efficiency gene transfer mediated by adenovirus-polylysine-DNA complexes.
Explore the source record for details and available documents.
Adenoviridae↗
Biomedical subjects
D T Curiel
Publications and source records attributed to D T Curiel.
Immune response to a carcinoembryonic antigen polynucleotide vaccine.
We have constructed a DNA plasmid encoding the full length complementary DNA for human carcinoembryonic antigen (CEA) driven by the cytomegalovirus early promoter/enhancer (plasmid DNA encoding human CEA) and demonstrated that this plasmid can function as a polynucleotide vaccine. This polynucleotide vaccine induced humoral and/or cellular immune responses specific for human CEA in all 5 immunized mice. Lymphoblastic transformation data with the use of enriched T-cell populations detected the presence of CEA-specific memory T-cells in 3 of 5 mice. Lymphocytes from 2 of 5 mice had interleukin 2/interleukin 4 release in response to CEA. CEA specificity was confirmed by the absence of reactivity to a control antigen and lack of CEA reactivity among mice vaccinated with a control plasmid encoding chloramphenicol acetyltransferase. Four of 5 mice vaccinated with plasmid DNA encoding human CEA demonstrated anti-CEA antibody responses. This immune response compared favorably with a positive control group of mice immunized with vaccinia-CEA by a dose and schedule previously shown to induce immunoprotection and therapy against a human CEA expressing syngeneic murine colon carcinoma model. Studies are ongoing to establish the construct, dose, and schedule to elicit optimal CEA-specific immune response as well as immunoprotection and therapy against human CEA expressing syngeneic murine adenocarcinoma models.
Animals↗
Efficient foreign gene expression in Epstein-Barr virus-transformed human B-cells.
Epstein-Barr virus (EBV) is a herpesvirus that transforms B-cells (B-LCL) and has undergone intense scrutiny owing to its association with Burkitt's lymphoma, nasopharyngeal carcinoma, and immunoblastic lymphomas. B-LCL have also proven useful in the study of human immunology. We describe a novel system for inducing efficient foreign gene expression in B-LCL using biotinylated adenovirus as an endosome-disrupting agent. Plasmid DNA is coupled to the exterior of viral particles by streptavidin-polylysine chimeric proteins. Up to 67% of B-LCL may be induced to express foreign genes in vitro in transient expression systems, and gene expression lasts for at least 17 days. We have expressed firefly luciferase, beta-galactosidase (beta-gal), chloramphenicol acetyltransferase, HIV gag, and env genes, as well as infectious HIV, and the EBV-specific BZLF gene in B-LCL with this system. In vivo delivery of a beta-gal reporter gene to B-LCL was documented in a SCID mouse model. Potential applications include study of genetic regulation of EBV infection and transformation events, study of potential gene therapies for EBV-related B-cell tumors, and production of antigen-presenting cells for use in immunologic assays. Because of the high percentage of cells transformed and the length of foreign gene expression, the possibility of examining foreign gene expression in transient assays, without selection for clonal populations, exists.
Animals↗
Gene therapy for B-cell lymphoma in a SCID mouse model using an immunoglobulin-regulated diphtheria toxin gene delivered by a novel adenovirus-polylysine conjugate.
Despite advances in conventional therapy, many lives continue to be lost to common forms of B-cell cancers, including leukemias, lymphomas and multiple myeloma. We propose a novel approach to therapy of such cancers using controlled expression of a diphtheria toxin gene (DT-A) to kill malignant cells. We have previously demonstrated selective killing of various cell types, in vitro and in vivo, by cell-specific, transcriptionally controlled expression of this gene. Organ-specific ablation in otherwise healthy transgenic mice has convincingly demonstrated the exquisite specificity achievable by this technique. In the studies now described, DT-A was delivered in vitro and in vivo using a novel gene delivery system employing DNA physically attached to the exterior of adenovirus. After demonstrating the efficacy of gene delivery to Epstein-Barr virus transformed human B-cells in vitro, in vivo work was performed using a SCID mouse model for B-cell lymphoma, in which protection against tumor was observed. The concepts of tissue-regulated toxin gene therapy, and this novel adenovirus gene delivery system are discussed.
Adenoviridae↗
Surfactant protein A-directed toxin gene kills lung cancer cells in vitro.
Human surfactant protein A (SPA) expression is considered a marker of respiratory epithelial differentiation. Non-small cell lung cancers (NSCLC) are respiratory epithelial derivatives, and it was previously shown that a minority of these cancers expressed SPA, presumably a consequence of their respiratory epithelial origin. In the studies reported here, SPA-I gene transcriptional regulatory sequences were localized to a 2.75-kb genomic 5'-flanking region fragment obtained by screening a human genomic library. The 2.75-kb fragment was used to direct a luciferase coding sequence transcriptionally within a plasmid construct. In plasmid transduction experiments, the SPA-directed luciferase plasmid produced significant luciferase activity in the SPA-expressing NSCLC cell line, H441, but only background levels in the non-SPA-expressing A549 cells. Because Northern blot analysis of resected NSCLC showed that the majority expressed SPA, an SPA-transcriptional targeting strategy was investigated using chimeric toxin genes comprising the coding sequence for herpes simplex virus thymidine kinase (HSV-TK) under transcriptional control of SPA or SV40 regulatory sequences. As expected, transduction of the constitutive, SV40-directed plasmid followed by ganciclovir treatment reduced numbers of both the A549 and H441 cells. In contrast, the SPA-directed plasmid reduced only the SPA-expressing H441 cells and had no significant effect on the A549 cells. The results of these in vivo experiments suggest the concept of transcriptionally directing toxin genes with SPA can produce targeted toxicity in NSCLC.
Carcinoma, Non-Small-Cell Lung↗
Trans complementation of an E1A-deleted adenovirus with codelivered E1A sequences to make recombinant adenoviral producer cells.
Replication-incompetent adenovirus is conventionally produced by cells that supply replication-enabling proteins from viral sequences present in trans. As an alternative means of recombinant adenovirus production, replication-enabling E1A sequences were cotransduced into human prostate carcinoma cells infected with an E1A-deleted adenovirus containing a luciferase expression cassette. The replication-enabling plasmid was cotransduced by ionic linkage to the recombinant adenovirus exterior. Cells cotransduced with the replication-enabling plasmid made new adenovirus with titers up to 8 x 10(6) in the supernatants 72-120 hr after transduction. Like the parent virus, the virus present in the cotransduced supernatants and lysates was capable of transferring luciferase activity to new cells. The virus present in the cotransduced cell supernatants was amplified and shown to be identical to the parent virus by genomic analysis. It was concluded that simultaneous addition of a replication-defective adenovirus and a replication-enabling gene sequence in a trans configuration converts some of the cotransduced cells into recombinant adenovirus-producing cells.
Adenovirus E1A Proteins↗
Efficient transfection of primary cells in a canine hemophilia B model using adenovirus-polylysine-DNA complexes.
We have used molecular conjugates containing combinations of DNA, adenovirus, polylysine, and transferrin to transfect primary cells derived from canines with hemophilia B (factor IX deficiency), as well as a canine epithelial cell line. Transfection of canine hemophilia B fibroblasts with molecular conjugates resulted in efficient transfection and expression of luciferase DNA-adenovirus-polylysine (AdpL) conjugates or luciferase DNA-adenovirus-polylysine-transferrin (hTfpL/AdpL) conjugates. No expression in canine hemophilia B fibroblasts was evident after exposure to DNA alone, or DNA conjugated with polylysine and transferrin. Transfection efficiencies of 50% or more could be demonstrated in cells transfected with a beta-galactosidase reporter gene as part of an hTfpL/AdpL molecular conjugate. Transfection with canine factor IX AdpL conjugates or canine factor IX hTfpL/AdpL conjugates resulted in factor IX expression for more than 2 weeks in vitro in hemophilia B canine fibroblasts. Maximum levels of expression of over 700 ng of canine factor IX/10(6) cells/24 hr were demonstrated in fibroblasts after transfection with canine factor IX hTfpL/AdpL conjugates. Similar conjugates were used to transfect hemophilia B canine bone marrow stromal cells and Madin-Darby canine kidney cells that also expressed canine factor IX. The use of molecular conjugates to transfect primary cells may be feasible as a means of in vitro or in vivo gene therapy for hemophilia B, and can be tested in the canine hemophilia B model.
Adenoviridae↗
Strategy for achieving selective killing of carcinomas.
Carcinomas are malignancies derived from epithelial cells that frequently respond poorly to conventional chemotherapy. Selective expression or transduction of toxin genes to carcinomas, i.e. molecular chemotherapy, may offer important advantages over conventional chemotherapy. As one approach to developing a means of selectively expressing toxin genes, the transcriptional regulatory sequences of a gene expressed in multiple carcinomas were used to direct expression of the herpes simplex virus thymidine kinase (HSVtk) coding sequences. The secretory leukoprotease inhibitor (SLPI) gene was found to be expressed in lung, breast, oropharyngeal, bladder, endometrial, ovarian and colorectal carcinomas. The tissue-specific transcriptional regulatory sequences were isolated and used to construct a chimeric gene in which the SLPI sequences directed HSVtk expression. SLPI-expressing carcinomas were reduced in number by transduction of the SLPI-directed toxin plasmid plus ganciclovir, but the same treatment had no effect on a cell line that did not express SLPI. These results suggest that SLPI-directed therapeutic genes could be used for directing toxicity to carcinoma tissues, especially if combined with other targeting strategies.
Adenoviridae↗
Strategies to achieve targeted gene delivery via the receptor-mediated endocytosis pathway.
Gene transfer to eukaryotic cells may be accomplished by capitalizing on endogenous cellular pathways of macromolecular transport. In this regard, molecular conjugate vectors have been developed which deliver DNA via the receptor-mediated endocytosis pathway. An attractive feature of this vector system is the potential to achieve targeted gene delivery based upon flexible incorporation of a targeting ligand. In this review we describe steps that have been taken to optimize this vector system. Specific strategies include the incorporation of mechanisms to achieve conjugate escape from the endosome and the derivation of methods to eliminate sources of nonspecificity. These developments have demonstrated the potential to construct a vector system in which multiple independent components may function in a concerted manner to accomplish targeted high efficiency gene delivery. In their present state of development, molecular conjugate vectors may have many potential applications for in vitro use.
Adenoviridae↗
Receptor-mediated gene delivery employing lectin-binding specificity.
Selective targeting of malignant cells will be necessary to implement many of the gene therapy strategies being designed to combat cancer. Targeting can be achieved by transductional or transcriptional approaches. Transductional targeting can be accomplished by exploiting differences in the molecules or receptors expressed on the cell surface of malignant versus normal cells. Given that malignant cells can be distinguished from normal by differences in the expression of cell surface carbohydrates, we hypothesized that transductional targeting would be feasible by molecular conjugate vectors which achieve cell binding by virtue of lectins directed against the cell surface glycocalyx. We have shown that gene transfer can be accomplished by these novel lectin-targeted molecular conjugate vectors and that lectin binding specificities may serve as a means for potential targeting of cancer cells for the purposes of gene therapy.
Animals↗
Intracellular single-chain antibody directed against erbB2 down-regulates cell surface erbB2 and exhibits a selective anti-proliferative effect in erbB2 overexpressing cancer cell lines.
Overexpression of the tyrosine kinase receptor erbB2 is important in the pathogenesis of a variety of neoplasms. Based on this concept, targeted anti-cancer strategies have been designed to selectively eradicate erbB2 overexpressing tumor cells. These strategies have employed either monoclonal antibodies or antibody toxin molecules with specificity for the cell surface erbB2 protein. As an alternative strategy, anti-erbB2 single-chain immunoglobulin (sFv) genes were constructed to direct expression of intracellular anti-erbB2 antibodies. Expression of an endoplasmic reticulum (ER) form of the anti-erbB2 sFv resulted in a profound down-regulation of cell surface erbB2 in an erbB2 overexpressing ovarian carcinoma cell line. In addition, expression of the intracellular antibody resulted in marked inhibition of tumor cell proliferation. Whereas stable transfectants expressing the anti-erbB2 sFv could be dervied from non-erbB2 overexpressing cancer cell lines, expression of the intracellular antibody was incompatible with long-term survival of the erbB2 overpressing tumor cells. The ability to selectively 'knock-out' erbB2 demonstrates that cell surface localization of erbB2 is essential to its ability to induce aberrant cellular proliferation in tumor cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Molecular conjugate vectors mediate efficient gene transfer into gastrointestinal epithelial cells.
Transfer of genes to the gastrointestinal epithelium would be advantageous from investigational and therapeutic standpoints. Efficient transfer of DNA to the intestinal epithelial cells, however, has been problematic with conventional viral and nonviral vectors. As an alternative, we have utilized molecular conjugate vectors to transfer DNA to enterocytes via the receptor-mediated endocytosis pathway. We were able to achieve efficient transfection of transformed (Caco2 cells) and nontransformed gastrointestinal cells derived from neonatal piglets utilizing molecular conjugate vectors. Analysis of heterologous gene expression revealed that enterocytes could serve as a secretory cellular source of alpha 1-antitrypsin and factor IX. Transient expression of heterologous DNA persisted for up to 2 weeks following transfection. Our observations suggest that molecular conjugate vectors may represent a promising strategy in the transfer of genes to cells of the gastrointestinal tract.
Adenocarcinoma↗
Optimization of methods to achieve mRNA-mediated transfection of tumor cells in vitro and in vivo employing cationic liposome vectors.
Direct in vivo transfection of tumor nodules in situ via liposome-DNA complexes has been employed as a strategy to accomplish antitumor immunization. To circumvent the potential safety hazards associated with systemic localization of delivered DNA, the utility of mRNA transcript-mediated gene delivery was explored. Capped, polyadenylated mRNA transcripts encoding the firefly luciferase and Escherichia coli lacZ reporter genes were derived by in vitro transcription. Transfection of the human breast cancer cell line MDA-MB-435 in vitro was accomplished employing cationic liposome-mRNA complexes. Evaluation of a panel of cationic liposome preparations demonstrated significant differences in the capacity of the various preparations to accomplish mRNA-mediated transfection. Quantitative evaluation of in vitro transfection demonstrated that target cells could be transfected at a high level of efficiency. The mRNA liposome-complexes were evaluated for in vivo transfection of tumor nodules in human xenografts in athymic nude mice. It could be demonstrated the liposome-mRNA complexes were comparable in efficacy to liposome-DNA complexes in accomplishing in situ tumor transfection. Thus, mRNA may be considered as an alternative to plasmid DNA as a gene transfer vector for genetic immunopotentiation applications.
Breast Neoplasms↗
Binding-incompetent adenovirus facilitates molecular conjugate-mediated gene transfer by the receptor-mediated endocytosis pathway.
Molecular conjugate vectors may be constructed that accomplish high efficiency gene transfer by the receptor-mediated endocytosis pathway. In order to mediate escape from lysosomal degradation, we have incorporated adenoviruses into the functional design of the conjugate. In doing so, however, we have introduced an additional ligand, which can bind to receptors on the cell surface, undermining the potential for cell specific targeting. To overcome this, we have treated the adenovirus with a monoclonal anti-fiber antibody, which renders the virus incapable of binding to its receptor. The result is a multi-functional molecular conjugate vector, which has preserved its binding specificity while at the same time being capable of preventing lysosomal degradation of endosome-internalized conjugate-DNA complexes. This finding indicates that adenoviral binding is not a prerequisite for adenoviral-mediated endosome disruption.
Adenoviruses, Simian↗
Receptor-mediated gene transfer to airway epithelial cells in primary culture.
A variety of methods have been utilized for gene transfer to the cells of the airway epithelium. These have included DNA-mediated mechanisms of gene transfer as well as recombinant viral vectors. Despite the availability of these methods, limitations in their utility warrant the development of alternate systems. As an alternative, receptor-mediated endocytosis using transferrin-polylysine conjugates has been shown to transduce immortalized airway epithelial cells efficiently via a physiologic pathway. When transferrin-polylysine conjugates were used to transduce airway epithelial cells grown in primary culture, however, gene transfer occurred inefficiently. Investigation into this relative inefficiency centered on endosomal entrapment of the conjugate-DNA complex. Pretreatment of the cells with chloroquine, which causes vacuolization and disruption of the endosome, or co-delivery of adenoviral particles, which serves to lyse the endosomal membrane, were both associated with greatly improved gene transfer efficiency. These studies established that the relative refractory state of the airway epithelial cells in primary culture was secondary to the retention of the internalized material within the endosome. We thus explored the efficiency of conjugates that possessed a mechanism to escape this endosomal entrapment; adenovirus-polylysine conjugates and transferrin-polylysine/adenovirus-polylysine conjugates were thus employed. Gene transfer efficiency improved significantly with the adenovirus-containing conjugates. These data support the concept that conjugates can be synthesized that mediate highly efficient gene transfer to airway epithelial cells in primary culture via the receptor-mediated endocytosis pathway.
Adenoviridae↗
Gene therapy: principles and potentials.
Explore the source record for details and available documents.
Genetic Therapy↗
Adenovirus facilitation of molecular conjugate-mediated gene transfer.
Explore the source record for details and available documents.
Adenoviridae↗
Transferrinfection: a highly efficient way to express gene constructs in eukaryotic cells.
Explore the source record for details and available documents.
Adenoviridae↗