Search PubMed⌕ Search

Biomedical subjects

J D Harris

Publications and source records attributed to J D Harris.

At least 19 recordsLinked to original sources
PubMed2002

Inhibition of atherosclerosis in apolipoprotein-E-deficient mice following muscle transduction with adeno-associated virus vectors encoding human apolipoprotein-E.

Apolipoprotein E (apoE) is a multifunctional plasma glycoprotein involved in lipoprotein metabolism and a range of cell signalling phenomena. ApoE-deficient (apoE(-/-)) mice exhibit severe hypercholesterolaemia and are an excellent model of human atherosclerosis. ApoE somatic gene transfer and bone marrow transplantation in apoE(-/-) mice results in reversal of hypercholesterolaemia, inhibition of atherogenesis and regression of atherosclerotic plaque density. Replication defective adeno-associated virus vectors (rAAVs) are an attractive system currently in clinical trial for muscle-based heterologous gene therapy to express secreted recombinant plasma proteins. Here we have applied rAAV transduction of skeletal muscle to express wild-type (epsilon3) and a defective receptor-binding mutant (epsilon2) human apoE transgene in apoE(-/-) mice. In treated animals, apoE mRNA was present in transduced muscles and, although plasma levels of recombinant apoE fell below the detection levels of our ELISA (ie <10 ng/ml), circulating antibodies to human apoE and rAAV were induced. Up to 3 months after a single administration of rAAV/apoE3, a significant reduction in atherosclerotic plaque density in aortas of treated animals was observed (approximately 30%), indicating that low-level rAAV-mediated apoE3 expression from skeletal muscle can retard atherosclerotic progression in this well-defined genetic model.

Animals↗
PubMed2000

Effectiveness of zona pellucida protein ZPB as an immunocontraceptive antigen.

Immunization of female mammals with native zona pellucida (ZP) proteins is known to cause infertility. Since each human ZP protein is now available as a purified recombinant protein, is it possible to compare the immunocontraceptive potential of each ZP protein. A breeding study was conducted in cynomolgus monkeys (Macaca fasicularis) after immunization with recombinant human ZP (rhZP) proteins (ZPA, ZPB, ZPC) separately and in combinations. This study demonstrated that immunization with recombinant human ZPB (rhZPB) protein caused cynomolgus monkeys to become infertile for 9-35 months. A second study was conducted in baboons (Papio cynocephalus), which yielded a similar result. The baboons immunized with rhZPB became infertile for 9 to > 20 months. During the time of maximum antibody titre, some animals experienced disruption of the menstrual cycle, but eventually all of the animals resumed normal menstrual cycles. Control animals and animals immunized with other rhZP proteins all became pregnant before any of the rhZPB-treated animals. This is the first study in which a recombinant ZP protein has consistently induced infertility in a primate without permanent disruption of the normal menstrual cycle.

Animals↗
PubMed1999

Gene therapy with autologous, interleukin 2-secreting tumor cells in patients with malignant melanoma.

We vaccinated metastatic melanoma patients with irradiated, autologous melanoma cells genetically engineered to secrete interleukin 2 (IL-2) to investigate whether an anti-tumor immune response would be induced. Melanoma cell cultures were established from surgical specimens and were engineered to secrete IL-2 by infection with recombinant retrovirus. Twelve patients were vaccinated subcutaneously one, two, or three times with approximately 10(7) irradiated, autologous, IL-2-secreting tumor cells. Treatment was well tolerated, with local reactions at 11 of 24 injection sites and minor systemic symptoms of fever and headache after 6 injections. One patient developed anti-tumor DTH after the first vaccination and showed an increased response after the second vaccination. Anti-autologous tumor CTLs could be detected prevaccination in the peripheral blood of seven patients and their activity increased after vaccination in four patients. No UICC-defined clinical responses were seen, but three patients had stable disease for 7-15 months, one of whom has not yet progressed (15+ months). Thus, patient vaccination with autologous, genetically engineered tumor cells is feasible and safe. Anti-tumor DTH and CTLs can be induced in some patients with such a vaccine.

Adult↗
PubMed1999

Functional evidence of novel tumor suppressor genes for cutaneous malignant melanoma.

Losses of heterozygosity involving chromosomes 9 and 10 are frequent events in the development and progression of cutaneous malignant melanoma. To investigate whether specifically deleted chromosomal regions encode tumor suppressor genes (TSGs), we introduced normal chromosome 10 into the tumorigenic human metastatic melanoma cell line UACC-903 by microcell fusion. In addition, two chromosome 9 derivatives that were microdeleted in the region of the p16INK4A/p15INK4B locus were transferred to determine whether an additional melanoma TSG or TSGs reside on chromosome 9p, as indicated by previous melanoma allele loss studies. In comparison to parental cells, microcell hybrids generated with chromosomes 9 (microdeleted) and 10 displayed reduced anchorage-independent growth in soft agar and markedly reduced tumorigenicity in athymic (nu/nu) mice. These data define a TSG or TSGs that function independently of p15/p16 on chromosome 9 and provide evidence for a TSG (or TSGs) on chromosome 10 that may be important in melanoma development.

Agar↗
PubMed1999

Expression and purification of recombinant human zona pellucida proteins.

Recombinant human zona pellucida (rhZP) proteins (minus the N-terminal leader and the C-terminal transmembrane-like domain) were expressed in four different expression systems: bacteria, yeast, insect cells, and Chinese Hamster Ovary (CHO) cells. The recombinant proteins in each system were engineered with a C-terminal six histidine (His6) segment that was used to purify the proteins by metal affinity [either nickel (Ni) or cobalt (Co)] column chromatography. Each of the rhZP proteins was a candidate antigen as an immunocontraceptive vaccine. However, the rhZP proteins produced in bacteria, yeast and insect cell culture could only be purified after being solubilized by strong denaturants. After purification the final products of each of these expression systems required 6 M urea to maintain solubility. However, the rhZP proteins expressed by CHO cells were secreted into the media, and the soluble proteins could be purified to near homogeneity. In this report the expression and purification procedures used to produce and isolate these secreted proteins are described.

Animals↗
PubMed1996

Strategies for targeted gene therapy.

Genetic intervention for the therapy of human disease has long been a dream for scientists and clinicians alike, and the first steps towards reality have already been taken in clinical trials involving over 1000 patients around the world. The technology used in these initial experiments has limited potential for therapeutic effect and it is now appreciated that improvements in targeting gene delivery and gene expression are both required before real clinical benefit is achieved. The enormous advances made in the fields of molecular genetics and molecular biology of the last few years have set the scene for their translation into novel approaches to gene transfer and control, for gene therapy applications.

Adenoviridae↗
PubMed1996

IL-12 stimulation but not B7 expression increases melanoma killing by patient cytotoxic T lymphocytes (CTL).

Recent studies have demonstrated that rodent tumour cells engineered to secrete a variety of cytokines, or to express foreign antigens, MHC molecules or co-stimulatory molecules, are rejected by syngeneic animals. These observations have led to the initiation of a number of clinical trials using genetically modified tumour cells, to attempt to stimulate a patient anti-tumour immune response. In this study, a protocol has been developed to test in vitro the specific cytotoxic anti-tumour response generated from melanoma patient lymphocytes. The results showed that IL-12 in combination with IL-2 enhanced the autologous anti-melanoma CTL response, whereas B7.1 antigen expression on tumour cells did not increase anti-melanoma CTL generation. This method could be used to design more appropriate genetically modified tumour vaccines.

B7-1 Antigen↗
PubMed1996

Mapping of epitopes on porcine zona pellucida-3 alpha by monoclonal antibodies inhibiting oocyte-sperm interaction.

Zona pellucida glycoprotein 3 alpha (ZP3 alpha) has been designated as the primary sperm receptor ligand in porcine gamete interaction. In this study, epitopes were mapped on porcine ZP3 alpha (pZP3 alpha) by using monoclonal antibodies (mAbs) possessing in vitro contraceptive efficacy. Using Western blots, we tested recombinant pZP3 alpha fragments expressed as fusion proteins in Escherichia coli and corresponding to pZP3 alpha precursor protein amino acid residues 18-142 (F1), 140-243 (F2), 239-363 (F3), and 359-462 (F4), for reactivities with mAbs. MAb-403 reacted with F3, and mAbs-412 and -421 with F2. MAb-420 showed weak reactivity with F1. Synthesis of overlapping 12-mer peptides further resolved the epitope for mAb-420 to amino acid residues 133-144, mAb-421 to 157-168, mAb-412 to 205-216, and mAb-403 to 301-312. MAbs-412 and -420 inhibited the binding of boar sperm to zona-encased porcine oocytes. These results, the first to define peptide epitopes of pZP3 alpha, should assist in the design of a synthetic peptide-based immunocontraceptive vaccine.

Animals↗
PubMed1996

The expression and localization of zona pellucida glycoproteins and mRNA in cynomolgus monkeys (Macaca fascicularis).

The zona pellucida (ZP) is an extracellular matrix composed of multiple glycoproteins that surrounds all mammalian oocytes. Analysis of the genes encoding the ZP proteins indicates that there are three classes ZPA (largest), ZPB (intermediate) and ZPC (smallest). Polyclonal antibodies developed against recombinant proteins of human and pig ZP have been used to identify immunohistochemically the components of the ZP of cynomolgus monkeys during the course of follicular development. Digoxigenin-labelled cDNA probes specific for the mRNA encoding ZPA, ZPB or ZPC were used to probe sections of cynomolgus monkey ovaries by in situ hybridization. mRNA encoding ZPA was identified in growing follicles at all stages and was seen in the granulosa cells of mature preovulatory follicles. ZPB protein and mRNA encoding ZPB were present in oocytes in secondary follicles and to a lesser extent in tertiary follicles, but were not found in primordial, primary or antral follicles or granulosa cells. ZPC protein and mRNA encoding ZPC were present in oocytes at all stages of folliculogenesis. These results suggest that each component of the ZP is produced and secreted at specific stages of folliculogenesis and that granulosa cells may be contributing to the synthesis of ZPA and ZPC.

Animals↗
PubMed1996

Suicide gene expression induced in tumour cells transduced with recombinant adenoviral, retroviral and plasmid vectors containing the ERBB2 promoter.

In order to exploit the tumour-specific nature of ERBB2 expression for genetic prodrug-activation therapy, we have generated recombinant adenoviral, retroviral and plasmid vectors containing an expression cassette consisting of the ERBB2 promoter and herpes simplex virus thymidine kinase coding sequence. In the case of the adenoviral vectors, the expression cassette was introduced into the E1 or E3 region of the genome. All of the vectors were capable of sensitizing ERBB2-positive cells to the action of ganciclovir. In contrast to the retroviral and plasmid vectors, however, transduction with the adenoviral vectors also resulted in sensitization of ERBB2-negative cells to ganciclovir, infection of cell lines with a beta-galactosidase expressing adenovirus showed that the sensitizing effect was not due to adenoviral infection per as in all but one of the cell lines tested. This study demonstrates that the ERBB2 promoter can be used to induce ERBB2-dependent sensitization to ganciclovir when in the context of retroviral and plasmid vectors. Observations made in this study do, however, suggest that adenoviral vectors may not be the ideal system to engineer conditional expression, and possible explanation for this phenomenon are discussed.

Adenoviridae↗
PubMed1994

User fees.

Explore the source record for details and available documents.

Canada↗
PubMed1994

Cloning and characterization of zona pellucida genes and cDNAs from a variety of mammalian species: the ZPA, ZPB and ZPC gene families.

Full length zona pellucida cDNAs from cat, dog and pig that are homologous to the ZP2/rc75 genes from mouse, human and rabbit, a full length zona pellucida cDNA from cat and a gene and full length cDNA from human that are homologous to the rc55/ZP3 alpha genes from rabbit and pig, and full length zona pellucida cDNAs from cat, cow, dog, pig and rabbit that are homologous to the ZP3 genes from mouse, hamster, human and marmoset have been cloned and characterized. The members of these gene families are herein referred to as ZPA, ZPB and ZPC genes to avoid the confusion that currently exists in the zona pellucida of nomenclature. This report is the first to describe the presence all three major zona pellucida genes within individual mammalian species. Within the ZPA, ZPB and ZPC gene families, the DNA and deduced amino acid sequences are highly homologous to each other, and are most homologous between members of the same order within the class mammalia. These results imply that all or most mammalian species express the ZPA, ZPB and ZPC proteins, which form the zona pellucida layer surrounding the oocyte.

Animals↗