Biomedical subjects

P D Robbins

Publications and source records attributed to P D Robbins.

At least 37 records · Page 2Linked to original sources

PubMed2003

Human adenovirus type 35: nucleotide sequence and vector development.

In this report, we describe the complete 34,794 base pair genomic sequence of the human adenovirus serotype 35 (Ad35) Holden strain. The viral genome exhibits a compact organization similar to other adenoviral serotypes, with overlapping genes on both strands. In all, 47 open reading frames (ORFs) were identified, including early (E1, 2, 3, 4) and late (L1, 2, 3, 4, 5) regions conserved among the adenoviridae family. In addition, 14 ORFs were identified that do not encode known adenoviral genes. Comparison of the predicted translational products of the conserved genes with those of other adenoviruses revealed that Ad35 has high homology to Ad7, Ad3, Ad21, Ad17, and simian Ads25. Based on the complete Ad35 DNA sequence, E3-, E1-, and E1/E3-deleted Ad35-based vector systems were developed. An HEK293-derived cell line was established for the propagation of the E1-deleted Ad35 vector, avoiding the emergence of replication-competent adenovirus. Moreover, production of the E1-deleted recombinant Ad35 vector was achieved by transient transduction of a plasmid encoding the Ad35 E1B gene in HEK293 cells. Testing showed that the Ad35-based vector efficiently infects both human and rhesus macaque dendritic cells. Our novel Ad35-based vectors and their corresponding packaging cell lines will provide a versatile and powerful system for DNA-based vaccine development and gene therapy applications.

Adenovirus E1 Proteins↗

PubMed2003

The contralateral effect conferred by intra-articular adenovirus-mediated gene transfer of viral IL-10 is specific to the immunizing antigen.

We have demonstrated previously that local, adenoviral-mediated gene transfer of vIL-10 to a single joint of rabbits and mice with experimental arthritis can suppress disease in both the treated and untreated contralateral joints. These therapeutic effects observed in distant untreated joints following local intra-articular gene delivery have been termed the 'contralateral effect'. To begin to understand the underlying immunologic mechanism that confers this effect, a dual-antigen model of antigen-induced arthritis (AIA) in rabbit knee joints was utilized. Rabbits were immunized against two antigens, ovalbumin and keyhole limpet hemocyanin, and AIA generated by intra-articular injection of each antigen into contralateral knees. Intra-articular adenovirus-mediated gene transfer of vIL-10 significantly reduced intra-articular leukocytosis and cartilage matrix degradation, while preserving near normal levels of cartilage matrix synthesis within treated joints. However, no antiarthritic effect was conferred in the contralateral control joints that received only a marker gene, in contrast to the results seen in a single-antigen AIA model. These results suggest that the distant antiarthritic effects associated with local gene delivery to joints are antigen-specific, and not due to vIL-10-induced generalized immunosuppression of the animal.

Adenoviridae↗

PubMed2003

TNF receptor gene therapy results in suppression of IgG2a anticollagen antibody in collagen induced arthritis.

BACKGROUND: Therapeutic strategies to block tumour necrosis factor alpha (TNFalpha) activity in experimental autoimmune arthritis models and rheumatoid arthritis (RA) have proved highly successful, and provide sustained beneficial effects. OBJECTIVE: To examine whether TNFalpha inhibition has immunological activity beyond the reduction of inflammation in collagen induced arthritis (CIA), an established experimental model of RA. METHODS: Arthritic DBA/1 mice received single periarticular injections of retroviral constructs encoding human TNF receptor (TNF-R) into the affected arthritic paw, at the onset of arthritis. Severity of arthritis, antibodies to collagen type II (CII), and extent of pathological joint damage of arthritic paws were compared between TNF-R and media treated (control) animals 3, 7, 14, 21, and 49 days after disease onset. RESULTS: Severity of CIA was significantly decreased in TNF-R treated animals compared with controls, 14-34 days after disease onset. Joint destruction was reduced in TNF-R injected joints and in the uninjected contralateral and ipsilateral paws of TNF-R treated animals. Seven days after disease onset, TNF-R treated mice had lower levels of inflammatory Th1 driven IgG2a antibodies to CII (p<0.05) than controls. This altered the anticollagen IgG2a:IgG1 ratio towards Th2 driven IgG1. CONCLUSIONS: Local TNF-R gene therapy in CIA appears to have systemic effects on the anti-CII antibodies. The overall influence of TNF-R gene therapy is that it inhibits the progression of CIA mainly by suppressing the inflammatory Th1 response rather than by stimulating a Th2 response. Therefore, periarticular TNF-R gene therapy may have excellent therapeutic potential in RA.

Animals↗

PubMed2002

IL-1Ra and vIL-10 gene transfer using retroviral vectors ameliorates particle-associated inflammation in the murine air pouch model.

OBJECTIVE: This study examined anti- inflammatory gene therapy to ameliorate tissue responses to ultra high molecular weight polyethylene (UHMWPE) particles in the murine air pouch. METHODS: Retroviruses encoding human interleukin- 1 receptor antagonist (IL-1Ra), viral interleukin-10 (vIL-10), or LacZ (reporter) genes were injected into murine air pouches stimulated by UHMWPE particles. Pouch membranes and fluids were harvested at 1, 3 and 7 days post gene-transduction, and assayed for markers of inflammation using histological, molecular, and immunological techniques. RESULTS: Real time RT-PCR and ELISA showed a strong production of IL-1beta in pouch tissue and lavage fluid induced by particle stimulation, accompanied by a lower expression of IL-6, TNF-alpha and IL-4. Transduction of IL-1Ra or vIL-10 genes resulted in a significant reduction of IL-1beta both at the mRNA and at the protein level. The gene therapy also resulted in diminution of IL-6 and TNF-alpha expression. In addition, significant elevation of TGF-beta expression was observed in IL-1Ra transduced pouches. Histological analysis revealed that the membranes of pouches transduced with vIL-10 or IL-1Ra were significantly less inflamed than the membranes of non-viral and LacZ-transduced pouches, with less cellular proliferation and lowered monocyte/macrophage influx. CONCLUSIONS: IL-1Ra or vIL-10 gene transduction was effective in ameliorating local inflammation by reducing the IL-1 production and subsequent cellular events elicited in response to UHMWPE particles in this model. These findings suggest that IL-1 directed gene therapy might be excellent therapeutic candidates to prevent or retard the inflammatory response to wear debris that contributes to the pathology of aseptic loosening.

Air↗

PubMed2002

Treatment of experimental equine osteoarthritis by in vivo delivery of the equine interleukin-1 receptor antagonist gene.

Osteoarthritis in horses and in humans is a significant social and economic problem and continued research and improvements in therapy are needed. Because horses have naturally occurring osteoarthritis, which is similar to that of humans, the horse was chosen as a species with which to investigate gene transfer as a potential therapeutic modality for the clinical treatment of osteoarthritis. Using an established model of equine osteoarthritis that mimics clinical osteoarthritis, the therapeutic effects resulting from intra-articular overexpression of the equine interleukin-1 receptor antagonist gene through adenoviral-mediated gene transfer were investigated. In vivo delivery of the equine IL-IRa gene led to elevated intra-articular expression of interleukin-1 receptor antagonist for approximately 28 days, resulting in significant improvement in clinical parameters of pain and disease activity, preservation of articular cartilage, and beneficial effects on the histologic parameters of synovial membrane and articular cartilage. Based on these findings, gene transfer of interleukin-1 receptor antagonist is an attractive treatment modality for the equine patient and also offers future promise for human patients with osteoarthritis.

Adenoviridae↗

PubMed2002

Redirecting adenovirus to pulmonary endothelium by cationic liposomes.

Somatic gene transfer to the pulmonary endothelium may be a useful strategy for modifying the phenotype of endothelium and/or vascular smooth muscle in disorders such as primary pulmonary hypertension, ARDS or pulmonary metastatic disease. Adenoviral (Ad) vectors, although highly efficient in liver gene transfer, have proven to be limited for pulmonary gene transfer with respect to efficiency, in part because of difficulty in assuring significant residence time in the lung and/or paucity of receptors for adenovirus on the endothelium. A recent study has shown that the use of a bispecific antibody to endothelial cells and Ad vectors efficiently redirects Ad vectors to pulmonary endothelium and improves gene expression in the lung. In this study, we report that pulmonary gene transfer by Ad vectors can also be improved significantly via the use of cationic liposomes. Preinjection of cationic liposomes followed by adenovirus led to a significant increase in the level of gene expression in the lung. The improvement in pulmonary gene transfer was associated with a decrease in the level of gene expression in the liver. Gene expression in the lung lasted for up to 2 weeks. This protocol, together with genetic modification of adenovirus, may prove to be useful for pulmonary gene transfer for the treatment of pulmonary diseases. This method may also be extended to pulmonary gene transfer using other types of viral vectors via vascular route.

Adenoviridae↗

PubMed2002

Inhibition of cartilage destruction by double gene transfer of IL-1Ra and IL-10 involves the activin pathway.

The objective of the study was to determine the effects and the molecular background of interleukin-1 receptor antagonist (IL-1Ra) and vIL-10 double gene transfer into human synovial fibroblasts from patients with rheumatoid arthritis (RA) using the SCID mouse model for cartilage erosion in RA. RA synovial fibroblasts were transduced with retro- or adenoviruses encoding IL-1Ra and/or viral IL-10 (vIL-10). SCID mice were engrafted subcutaneously with IL-1Ra and vIL-10 transduced human rheumatoid synovial fibroblasts and normal cartilage. In parallel, gene expression analysis before and after gene transfer using RNA arbitrarily primed PCR in combination with cDNA array was performed. vIL-10 and IL-1Ra double gene transfer resulted in inhibition of cartilage invasion and degradation by RA synovial fibroblasts when compared with control transduced and non-transduced implants. Expression of key genes that were altered after double gene transfer were related to the activin pathway. The results demonstrate not only that virus-based gene transfer using a combination of two joint-protective genes is a feasible approach to inhibit cartilage degradation by activated RA synovial fibroblasts, but also that the underlying molecular effects include modulation of the activin pathway.

Actins↗

PubMed2002

Therapeutic and specific antitumor immunity induced by co-administration of immature dendritic cells and adenoviral vector expressing biologically active IL-18.

Interleukin-18 is a potent cytokine expressed early in the immune response following cleavage in activated composes. We have investigated the in vivo antitumor effects of intratumoral (i.t.) administration of an adenoviral vector expressing biologically active murine interleukin (IL)-18 (Ad.PTH.IL-18). Substantial antitumor effects were observed when established MCA205 fibrosarcoma was treated in syngeneic immunocompetent mice with intratumoral injection of Ad.PTH.IL-18 (P = 0.0025 versus control vector treatment), generating potent cytotoxic T lymphocytes (CTLs) in culture. In contrast, the antitumor effect was absent, and cytotoxic activity was significantly less (P = 0.021) in gld mice (Fas ligand deficient). To enhance the in vivo antitumor activity of the treatment using Ad.PTH.IL-18, we co-injected immature DC and Ad.PTH.IL-18 i.t. into established, day 7 MCA205 fibrosarcoma and MC38 adenocarcinoma. Co-injection of both Ad.PTH.IL-18 and DC was associated with complete abrogation of injected tumors. Furthermore, the antitumor effects were also observed on distant tumors inoculated i.d. in the contralateral flank of the animal. The induced cytolytic activity was tumor-specific and MHC class I-restricted. As we have previously demonstrated in vitro (Tanaka F et al, Cancer Res 2000; 60: 4838-4844) and consistent with these findings in vivo, NK, T and dendritic cells coactivately mediate the IL-18 enhanced antitumor effect. This study suggests that the coactivate strategy could be used in the clinical setting to treat patients with cancer. do

Adenosarcoma↗

PubMed2001

A proapoptotic peptide for the treatment of solid tumors.

We have designed a novel peptide, DP1, which is able to mediate significant induction of apoptosis in solid tumors by local injection. This peptide, comprised of a protein transduction domain (PTD), PTD-5, fused to an antimicrobial peptide, (KLAKLAK)2, was able to trigger rapid apoptosis in a variety of cell lines in vitro, including MCA205 murine fibrosarcomas and human head and neck tumors. Furthermore, direct injection of DP1 into day 7 established MCA205 tumors in C57BL/6 mice resulted in the induction of tumor apoptosis and subsequent reduction in tumor volume. These results suggest that DP1 may be used clinically to treat accessible solid tumors or as an adjuvant therapy in conjunction with radiotherapy, standard chemotherapy, immunotherapy, or surgical debulking.

Amino Acid Sequence↗

PubMed2001

Approaches to enhancing the retroviral transduction of human synoviocytes.

This report concerns a clinical trial for rheumatoid arthritis (RA), approved by the US National Institutes of Health and the Food and Drug Administration. An amphotropic retrovirus (MFG-IRAP) was used ex vivo to transfer a cDNA encoding human interleukin-1 receptor antagonist (IL-1Ra) to synovium. The protocol required the transduced cells to secrete at least 30 ng IL-1Ra/10(6) cells per 48 h before reimplantation. Here we have evaluated various protocols for their efficiency in transducing cultures of human rheumatoid synoviocytes. The most reliably efficient methods used high titer retrovirus (approximately 10(8) infectious particles/ml). Transduction efficiency was increased further by exposing the cells to virus under flow-through conditions. The use of dioctadecylamidoglycylspermine (DOGS) as a polycation instead of Polybrene (hexadimethrine bromide) provided an additional small increment in efficiency. Under normal conditions of static transduction, standard titer, clinical grade retrovirus (approximately 5 x 10(5) infectious particles/ml) failed to achieve the expression levels required by the clinical trial. However, the shortfall could be remedied by increasing the time of transduction under static conditions, transducing under flow-through conditions, or transducing during centrifugation.

Arthritis, Rheumatoid↗

PubMed2001

Demonstration of direct effects of growth hormone on neonatal cardiomyocytes.

The cellular and molecular basis of growth hormone (GH) actions on the heart remain poorly defined, and it is unclear whether GH effects on the myocardium are direct or mediated at least in part via insulin-like growth factor (IGF-1). Here, we demonstrate that the cultured neonatal cardiomyocyte is not an appropriate model to study the effects of GH because of artifactual loss of GH receptors (GHRs). To circumvent this problem, rat neonatal cardiomyocytes were infected with a recombinant adenovirus expressing the murine GHR. Functional integrity of GHR was suggested by GH-induced activation of the cognate JAK2/STAT5, MAPK, and Akt intracellular pathways in the cells expressing GHR. Although exposure to GH resulted in a significant increase in the size of the cardiomyocyte and increased expression of c-fos, myosin light chain 2, and skeletal alpha-actin mRNAs, there were no significant changes in IGF-1 or atrial natriuretic factor mRNA levels in response to GH stimulation. In this model, GH increased incorporation of leucine, uptake of palmitic acid, and abundance of fatty acid transport protein mRNA. In contrast, GH decreased uptake of 2-deoxy-d-glucose and levels of Glut1 protein. Thus, in isolated rat neonatal cardiomyocytes expressing GHR, GH induces hypertrophy and causes alterations in cellular metabolic profile in the absence of demonstrable changes in IGF-1 mRNA, suggesting that these effects may be independent of IGF-1.

Adenoviridae↗

PubMed2001

Interleukin 12 gene therapy of cancer by peritumoral injection of transduced autologous fibroblasts: outcome of a phase I study.

A phase I dose-escalation clinical trial of peritumoral injections of interleukin 12 (IL-12)-transduced autologous fibroblasts was performed in patients with disseminated cancer for whom effective treatment does not exist. The goals of this study were to assess the safety and toxicities as well as the efficacy, and ancillarily the immunomodulatory effects, of peritumoral IL-12 gene transfer. Primary dermal fibroblasts cultured from the patients were transduced with retroviral vector carrying human IL-12 genes (p35 and p40) as well as the neomycin phosphotransferase gene (TFG-hIL-12-Neo). Patients received four injections at intervals of 7 days. Nine patients were enrolled in this dose-escalation study, with secreted IL-12 doses ranging from 300 ng/24 hr for the first three patients to 1000, 3000, and 5000 ng/24 hr for two patients in each subsequent dosage level. Although a definite statement cannot be made, there appears to be perturbation of systemic immunity. Also, the locoregional effects mediated by tumor necrosis factor alpha (TNF-alpha) and CD8+ T cells were observed with tumor regression. Treatment-related adverse events were limited to mild to moderate pain at the injection site; clinically significant toxicities were not encountered. Transient but clear reductions of tumor sizes were observed at the injected sites in four of nine cases, and at noninjected distant sites in one melanoma patient. Hemorrhagic necrosis of tumors was observed in two melanoma patients. These data indicate that gene therapy by peritumoral injection of IL-12-producing autologous fibroblasts is feasible, and promising in patients with advanced cancer.

Adult↗

PubMed2001

A conserved XIAP-interaction motif in caspase-9 and Smac/DIABLO regulates caspase activity and apoptosis.

X-linked inhibitor-of-apoptosis protein (XIAP) interacts with caspase-9 and inhibits its activity, whereas Smac (also known as DIABLO) relieves this inhibition through interaction with XIAP. Here we show that XIAP associates with the active caspase-9-Apaf-1 holoenzyme complex through binding to the amino terminus of the linker peptide on the small subunit of caspase-9, which becomes exposed after proteolytic processing of procaspase-9 at Asp315. Supporting this observation, point mutations that abrogate the proteolytic processing but not the catalytic activity of caspase-9, or deletion of the linker peptide, prevented caspase-9 association with XIAP and its concomitant inhibition. We note that the N-terminal four residues of caspase-9 linker peptide share significant homology with the N-terminal tetra-peptide in mature Smac and in the Drosophila proteins Hid/Grim/Reaper, defining a conserved class of IAP-binding motifs. Consistent with this finding, binding of the caspase-9 linker peptide and Smac to the BIR3 domain of XIAP is mutually exclusive, suggesting that Smac potentiates caspase-9 activity by disrupting the interaction of the linker peptide of caspase-9 with BIR3. Our studies reveal a mechanism in which binding to the BIR3 domain by two conserved peptides, one from Smac and the other one from caspase-9, has opposing effects on caspase activity and apoptosis.

Amino Acid Motifs↗

PubMed2001

Effective treatment of established murine collagen-induced arthritis by systemic administration of dendritic cells genetically modified to express IL-4.

Dendritic cells (DC) are APCs that are able to stimulate or inhibit immune responses, depending on levels of expression of MHC class I and II costimulatory molecules and cytokines. Our previous studies have suggested that the observed contralateral effect, where injection of a vector carrying certain immunomodulatory genes into one joint resulted in inhibition of arthritis in untreated joints, is mediated by in vivo modification of DC. Therefore, we have examined the ability of genetically modified DC to suppress established murine collagen-induced arthritis (CIA) after i.v. delivery. IL-4 has been shown to partially reduce the severity of CIA after repeated injection of recombinant protein or by injection of an adenoviral vector expressing IL-4. Here we demonstrate that i.v. injection of immature DC, infected with an adenoviral vector expressing IL-4, into mice with established CIA resulted in almost complete suppression of disease, with no recurrence for up to 4 wk posttreatment. Injection i.v. of fluorescently labeled DC demonstrated that the cells rapidly migrated to the liver and spleen after 6 h and to the lymph nodes by 24 h. In culture, spleen cells from DC/IL-4-treated mice produced less IFN-gamma after stimulation by collagen than did control groups. In addition, DC/IL-4 administration decreased the level of specific Abs against type II collagen, in particular the IgG2 Th1 isotype 14 days posttreatment. These results demonstrate the ability to treat effectively established murine arthritis by systemic administration of DC expressing IL-4.

Adenoviridae↗

PubMed2001

Future of adenoviruses in the gene therapy of arthritis.

Recombinant adenoviruses are straightforward to produce at high titres, have a promiscuous host-range, and, because of their ability to infect nondividing cells, lend themselves to in vivo gene delivery. Such advantages have led to their widespread and successful use in preclinical studies of arthritis gene therapy. While adenoviral vectors are well suited to 'proof of principle' experiments in laboratory animals, there are several barriers to their use in human studies at this time. Transient transgene expression limits their application to strategies, such as synovial ablation, which do not require extended periods of gene expression. Moreover, there are strong immunological barriers to repeat dosing. In addition, safety concerns predicate local, rather than systemic, delivery of the virus. Continued engineering of the adenoviral genome is producing vectors with improved properties, which may eventually overcome these issues. Promising avenues include the development of 'gutted' vectors encoding no endogenous viral genes and of adenovirus-AAV chimeras. Whether these will offer advantages over existing vectors, which may already provide safe, long-term gene expression following in vivo delivery, remains to be seen.

Adenoviruses, Human↗

PubMed2001

Direct adenovirus-mediated insulin-like growth factor I gene transfer enhances transplant chondrocyte function.

Cell-based cartilage-resurfacing procedures may be enhanced by the addition of insulin-like growth factor I (IGF-I) to the transplant biomatrix. Given the relatively short half-life of IGF-I in biological systems, however, maintenance of effective concentrations of this peptide necessitates either high initial doses, or repeated treatment. This study investigated IGF-I delivery via adenoviral gene therapy, targeting graftable articular chondrocytes. Cultured articular chondrocytes were infected with an E1-deleted adenoviral vector containing IGF-I-coding sequence under CMV promoter control. Increased adenovirus-IGF-I concentrations resulted in coordinate increase in IGF-I mRNA and ligand expression; however, chondrocyte matrix synthesis was maximized by the lower adenovirus-IGF-I concentration (100 MOI) without additional increase at 200 or 500 MOI. Using 100 MOI, infected monolayers produced medium IGF-I content of at least 10 ng/ml in each 48-hr period for 28 days, reaching a day 4 peak concentration of 66 +/- 4.0 ng/ml. These concentrations were sufficient to produce significant stimulation of normal cartilage matrix gene expression. The concentration of secreted matrix products in medium from infected monolayers was increased up to 8-fold over uninfected control cultures. Moreover, compared with uninfected cultures, cells in infected cultures were more resistant to de-differentiation over time under serum-starved conditions, maintaining a normal chondrocyte molecular phenotype for at least 28 days. These data indicate that cultured chondrocytes are readily transduced by recombinant adenoviral vectors. The adenoviral-IGF transgene is abundantly expressed and its product secreted at therapeutic concentrations for at least 28 days, resulting in increased matrix biosynthesis and maintenance of the chondrocytic phenotype. Combined, this information suggests that there may be significant value in preimplantation adenoviral-IGF gene therapy for chondrocytes destined for cartilage resurfacing.

Adenoviridae↗

PubMed2001

Herpesvirus-mediated systemic delivery of nerve growth factor.

Sustained systemic dissemination of therapeutic proteins from peripheral sites is an attractive prospect for gene therapy applications. Replication-defective genomic herpes simplex virus type 1 (HSV-1) vectors were evaluated for their ability to express nerve growth factor (NGF) as a model gene product both locally and systemically. Intra-articular inoculation of NGF expression vectors in rabbits resulted in significant increases in joint lavage and blood plasma NGF that persisted for 1 year. A rhesus macaque injected intra-articularly displayed a comparable increase in plasma NGF for at least 6 months, at which time the serum NGF levels of this animal were sufficient to cause differentiation of PC12 cells in culture, but not to increase footpad epidermis innervation. Long-term reporter transgene expression was observed primarily in ligaments, a finding confirmed by direct inoculation of patellar ligament. Patellar ligament inoculation with a NGF vector resulted in elevated levels of circulating NGF similar to those observed following intra-articular vector delivery. These results represent the first demonstration of sustained systemic release of a transgene product using HSV vectors, raising the prospect of new applications for HSV-1 vectors in the treatment of systemic disease.

Animals↗

PubMed2001

Gene transfer of p53 to arthritic joints stimulates synovial apoptosis and inhibits inflammation.

Rheumatoid arthritis (RA) is an autoimmune disease that primarily affects joints. During the pathogenesis of rheumatoid arthritis, the synovial lining becomes dramatically thickened and hyperplastic. This highly aggressive tissue invades and destroys articular cartilage and bone. Several lines of evidence suggest that the proliferation of the synovial tissue may be due to disruption in the control of the cell cycle or apoptotic pathways. In particular, mutations in the tumor suppressor protein p53 have been found in synovial tissue from RA joints. We have examined the effects of overexpression of p53 by adenoviral infection in synovial cells in culture and in synovial tissue in vivo in a rabbit model of arthritis. Here we demonstrate that p53 overexpression resulted in significant apoptosis in human and rabbit synovial cells in culture. Furthermore, intraarticular injection of Ad-p53 resulted in extensive and rapid induction of synovial apoptosis in the rabbit knee without affecting cartilage metabolism. Interestingly, a significant reduction in the leukocytic infiltrate was observed within 24 h postinfection of Ad.p53. These results suggest that intraarticular gene transfer of p53 is able to induce synovial apoptosis as well as reduce inflammation and thus may be useful clinically for the treatment of RA.

Adenoviridae↗