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Biomedical subjects

S C Ghivizzani

Publications and source records attributed to S C Ghivizzani.

At least 37 records · Page 2Linked to original sources

Gene therapy for autoimmune disorders.

Although many autoimmune disorders do not have a strong genetic basis, their treatment may nevertheless be improved by gene therapies. Most strategies seek to transfer genes encoding immunomodulatory products that will alter host immune responses in a beneficial manner. Used in this fashion, genes serve as biological delivery vehicles for the products they encode. By this means gene therapy overcomes obstacles to the targeted delivery of proteins and RNA, and improves their efficacy while providing a longer duration of effect, and, potentially, greater safety. Additional genetic strategies include DNA vaccination and the ablation of selected tissues and cell populations. There is considerable evidence from animal studies that gene therapies work: examples include the treatment of experimental models of rheumatoid arthritis, multiple sclerosis, diabetes, and lupus. Pre-clinical success in treating animal models of rheumatoid arthritis has led to the first clinical trial of gene therapy for an autoimmune disease. In this Phase I study, a cDNA encoding the interleukin-1 receptor antagonist was transferred to the knuckle joints of patients with advanced rheumatoid arthritis. Two additional clinical trials are in progress. It is likely that gene therapy will provide effective new treatments for a wide range of autoimmune disorders.

Animals↗

Genetic enhancement of fracture repair: healing of an experimental segmental defect by adenoviral transfer of the BMP-2 gene.

This study evaluated the ability of gene transfer to enhance bone healing. Segmental defects were created surgically in the femora of New Zealand white rabbits. First generation adenoviruses were used as vectors to introduce into the defects genes encoding either human bone morphogenetic protein-2 (BMP-2) or, as a negative control, firefly luciferase. Representative specimens were evaluated histologically after 8 weeks. Healing of the defects was monitored radiographically for 12 weeks, after which time the repair tissue was evaluated biomechanically. By radiological criteria, animals receiving the BMP-2 gene had healed their osseous lesions after 7 weeks, whereas those receiving the luciferase gene had not. Histologic examination of representative rabbits at 8 weeks confirmed ossification across the entire defect in response to the BMP-2 gene, whereas the control defect was predominantly fibrotic and sparsely ossified. At the end of the 12-week experiment, the control femora still showed no radiological signs of stable healing. The difference in radiologically defined healing between the experimental and control groups was statistically significant (P < 0. 002). Biomechanical testing of the femora at 12 weeks demonstrated statistically significant increases in the mean bending strength (P < 0.005) and bending stiffness (P < 0.05) of the animals treated with the BMP-2 gene. Direct, local adenoviral delivery of an osteogenic gene thus led to the healing of an osseous lesion that otherwise would not do so. These promising data encourage the further development of genetic approaches to enhancing bone healing. Gene Therapy (2000) 7, 734-739.

Adenoviridae↗

Ex vivo gene therapy to produce bone using different cell types.

Gene therapy and tissue engineering promise to revolutionize orthopaedic surgery. This study comprehensively compares five different cell types in ex vivo gene therapy to produce bone. The cell types include a bone marrow stromal cell line, primary muscle derived cells, primary bone marrow stromal cells, primary articular chondrocytes, and primary fibroblasts. After transduction by an adenovirus encoding for bone morphogenetic protein-2, all of the cell types were capable of secreting bone morphogenetic protein-2. However, the bone marrow stromal cell line and muscle derived cells showed more responsiveness to recombinant human bone morphogenetic protein-2 than did the other cell types. In vivo injection of each of the cell populations transduced to secrete bone morphogenetic protein-2 resulted in bone formation. Radiographic and histologic analyses corroborated the in vitro data regarding bone morphogenetic protein-2 secretion and cellular osteocompetence. This study showed the feasibility of using primary bone marrow stromal cells, primary muscle derived cells, primary articular chondrocytes, primary fibroblasts, and an osteogenesis imperfecta stromal cell line in ex vivo gene therapy to produce bone. The study also showed the advantages and disadvantages inherent in using each cell type.

Adenoviridae↗

Vector systems for gene transfer to joints.

The prospects for the development of gene therapy treatments for certain orthopaedic diseases have been fueled by advances in the understanding of the molecular components of these disorders. These studies have identified molecules that could have therapeutic or reparative effects in certain settings. The ability to transfer and appropriately express the genes encoding these molecules is dependent on the availability of effective gene transfer vectors. Numerous vector systems have been used to transfer and express genes in joints with varied levels of success. The current review is designed to briefly outline the basics of the different gene transfer vector systems available for use by researchers in the orthopaedic fields.

Adenoviridae↗

Using gene therapy to protect and restore cartilage.

Numerous gene products have the potential to help protect cartilage from degradation and to repair cartilage that has become damaged as a result of disease or injury. The genes that encode these products thus may serve as chondroprotective and chondroregenerative medicines. To bring these agents into clinical use, it is necessary to screen candidate genes for efficacy under in vitro and in vivo conditions, to determine the best cells to target, and to develop appropriate gene transfer technologies. As discussed in the current review, progress has been made in each of these areas. Various viral and nonviral vectors are able to deliver genes to synoviocytes, articular chondrocytes, and mesenchymal stem cells. There also is evidence to suggest that ex vivo and in vivo approaches can be used for gene transfer to articular cartilage, synovium, and meniscus. Moreover various cytokine antagonists and growth factors have been shown to protect cartilage and stimulate chondrogenesis. In vivo methods and strategies that target synovium may be useful in a chondroprotective mode but because they do not increase the number of chondrogenic cells within lesions, they may be ill-equipped to repair large defects. Ex vivo methods however, provide cells and genes. It also is important to distinguish the treatment of isolated lesions occurring as a result of injury from the treatment of lesions resulting from underlying disease processes. Additional development of these approaches should result in clinically useful genetic methods for the protection and regeneration of cartilagenous tissues.

Animals↗

Gene therapy approaches for treating rheumatoid arthritis.

Current gene therapy approaches for treating rheumatoid arthritis have made use of gene transfer technology as an improved delivery system for emerging proteins and other biologicals whose activities may have therapeutic value. Preclinical research has focused on two primary directions, evaluation of methods of gene delivery and identification of gene products with antiarthritic potential. Although there are reports involving systemic gene delivery, the bulk of effort has focused on local, intraarticular administration using ex vivo and in vivo methods. Viral-based vectors, including adenovirus, adeno-associated virus and herpes simplex virus have the greatest efficiency of gene delivery after intraarticular injection and are capable of generating relevant levels of gene products in several animal models of disease. However, there are limitations to existing generations of these systems that currently preclude their clinical application. Those gene products found to be efficacious in animal models of rheumatoid arthritis include proteins that specifically block the activity of the primary inflammatory cytokines, and include interleukin-1 receptor antagonist and soluble receptors for tumor necrosis factor and interleukin-1. Delivery and expression of genes encoding certain cytokines such as interleukins -4, -10, and -13 and viral interleukin-10, that block synthesis of inflammatory mediators and downregulate aspects of cellular and humoral immune pathways have been found beneficial. Although significant progress has been made, leading to Phase I clinical trials, there remain several hurdles to the routine practice of gene therapy for treatment of rheumatoid arthritis.

Animals↗

Clinical trials in the gene therapy of arthritis.

Gene therapy clinical trials raise important safety issues that complicate their design and require extensive preclinical testing. Human protocols for the treatment of arthritis and most other orthopaedic and rheumatologic indications are complicated additionally by the perception that they are largely acquired, nonlethal conditions. Taking these considerations into account, the first such human study used the local, ex vivo delivery of a gene whose product, the interleukin-1 receptor antagonist, has an outstanding safety profile. This gene was delivered to the metacarpophalangeal joints of postmenopausal women 1 week before these joints were removed during total joint replacement surgery. In addition to providing an additional safety cushion, the surgical removal of the genetically modified joints made available large amounts of tissue to examine for evidence of successful gene transfer and gene expression. This Phase I safety study was approved at the local and federal levels, and its funding was contingent on the establishment of an external monitoring board. This trial now has been completed and a Phase II, efficacy study is being planned. A similar study has begun in Dusseldorf, Germany and results from the first two patients are similar to the results of the American patients. Permission has been given for two additional human trials, one in the United States and one in the Netherlands, in which a gene encoding herpes thymidine kinase will be transferred to the joints of patients with rheumatoid arthritis who then will be administered gancyclovir. This procedure aims to treat the disease by producing a genetic synovectomy. Additional development of human gene therapies for arthritis and other orthopaedic and rheumatic conditions will be aided by the successful completion of these studies.

Animals↗

Cartilage injury and repair.

Articular cartilage is a complex structure that, once damaged, has little capacity for permanent repair. The problem lies in the inability of the body to regenerate tissue with the appropriate macromolecular constituents and architecture of normal hyaline cartilage. Although full-thickness defects are capable of stimulating a repair response, the resulting fibrocartilage is inferior and cannot withstand long-term, repetitive use. Numerous surgical approaches that involve penetration of subchondral bone offer short-term to moderate-term relief of symptoms, whereas other approaches have seen significant improvement through transplantation of osteochondral and periosteal tissue and implantation of autologous chondrocytes. Despite these procedures, articular cartilage damage continues to be an unmet clinical problem. Improvements in biochemical and molecular biologic techniques may allow advances in the understanding of chondrocyte and cartilage biology and may provide innovative and novel approaches to stimulating the repair of articular cartilage through biologic means.

Animals↗

Potential applications of gene therapy in sports medicine.

Gene therapy has the potential to improve greatly the management of sports medicine injuries. By the expeditious introduction of the appropriate genes to sites of injury, it should prove possible to initiate healing responses in those tissues that normally fail to heal, to accelerate healing in tissues which do naturally heal, and to improve the quality of the repair tissue. In addition, genes with anti-inflammatory properties offer novel possibilities for the control of chronic, sports related inflammation. None of these applications of gene therapy in sports medicine is yet in the clinic. It would seem, however, only a matter of time before the first clinical trials emerge. Their acceptance will be facilitated by the two human protocols that are presently underway for the treatment of rheumatoid arthritis. The present status of sports medicine gene therapy is summarized in Table 3.

Athletic Injuries↗

The Marshall R. Urist Young Investigator Award. Orthopaedic applications of gene therapy. From concept to clinic.

Gene therapy offers new possibilities for the clinical management of orthopaedic conditions that are difficult to treat by traditional surgical or medical means. To bring the potential of this novel technology into the clinic, a research program was initiated that aimed to identify orthopaedically useful genes and develop methods for delivering them to suitable sites under conditions in which gene expression remains at therapeutic levels for the appropriate periods of time; this program is now 10 years old. Rheumatoid arthritis was selected as the lead disease. Preclinical studies evaluating the local and systemic delivery of numerous different genes by in vivo and ex vivo methods in murine and lapin models led to the development of a human gene therapy protocol for arthritis. In this protocol, a gene encoding the human interleukin-1 receptor antagonist protein is transferred to the metacarpophalangeal joints of female patients with rheumatoid arthritis. The first patient was treated this way in July 1996. This is not only the first orthopaedic application of human gene therapy, but also the first use of gene therapy approved for a nonlethal disease. In addition to providing additional therapeutic options for the treatment of rheumatoid arthritis, the experimental data from this study suggest that gene transfer approaches may improve the treatment of osteoarthritis, the repair of cartilage, ligaments, tendons, menisci, intervertebral discs and bone, and the management of disorders such as osteoporosis and osteogenesis imperfecta. They also show promise as a means for developing novel and improved animal models of orthopaedic diseases. If the current rate of progress continues, wide clinical application of gene therapy in various orthopaedic indications should occur within the next 5 to 10 years.

Animals↗

Direct adenoviral gene transfer of viral IL-10 to rabbit knees with experimental arthritis ameliorates disease in both injected and contralateral control knees.

IL-10, a cytokine produced primarily by macrophages, B lymphocytes, and Th2 cells, has both immunostimulatory and immunosuppressive properties. A homologue of IL-10 encoded by EBV, known as viral IL-10 (vIL-10), is also able to suppress the immune response, but may lack some of the immunostimulatory properties of IL-10. To evaluate the potential of vIL-10 to block the progression of rheumatoid arthritis, we have utilized a replication-defective adenovirus vector to deliver the gene encoding vIL-10 to the knee joints of rabbits with Ag-induced arthritis. Intraarticular expression of vIL-10 significantly reduced leukocytosis, cartilage matrix degradation, and levels of endogenous rabbit TNF-alpha, as well as the degree of synovitis, while maintaining high levels of cartilage matrix synthesis. Interestingly, an antiarthritic effect was also observed in opposing contralateral control knee joints that received only a marker gene. An adenoviral vector carrying the enhanced green fluorescent protein marker gene was used to demonstrate that a morphologically similar subset of cells infected in the injected knee joint are able to traffic to the uninjected contralateral knee joint. Our results suggest that direct, local intraarticular delivery of the vIL-10 gene may have polyarticular therapeutic effects.

Adenoviruses, Human↗

Lessons learned from gene transfer approaches.

Recent technological advances allow the transfer of genes to the synovial lining of joints. As well as opening novel opportunities for therapy, these techniques provide valuable new tools for the study of synovitis and other aspects of the biology of joints in health and disease. This article reviews briefly the results of experiments in which selected genes have been transferred to the knee joints of healthy rabbits and rabbits with antigen-induced arthritis.

Animals↗

The role of gene therapy. Fact or fiction?

Current research in molecular biology and genetics has dramatically advanced the understanding of the cellular events involved in homeostasis, disease, injury, and healing processes of the tissues of the musculoskeletal system. Recently, genetic predispositions to diseases have been described which offer novel means to address musculoskeletal disorders. Growth factors and cytokines have been identified as key elements in both the injured and healing states. Gene therapy offers an elegant solution to the delivery of therapeutic proteins to the site of disease or injury.

Cytokines↗

Adenoviral gene transfer of the interleukin-1 receptor antagonist protein to human islets prevents IL-1beta-induced beta-cell impairment and activation of islet cell apoptosis in vitro.

The beta-cells in the pancreatic islets of Langerhans are the targets of autoreactive T-cells and are destroyed in type 1 diabetes. Macrophage-derived interleukin-1beta (IL-1beta) is important in eliciting beta-cell dysfunction and initiating beta-cell damage in response to microenvironmental changes within islets. In particular, IL-1beta can impair glucose-stimulated insulin production in beta-cells in vitro and can sensitize them to Fas (CD95)/FasL-triggered apoptosis. In this report, we have examined the ability to block the detrimental effects of IL-1beta by genetically modifying islets by adenoviral gene transfer to express the IL-1 receptor antagonist protein. We demonstrate that adenoviral gene delivery of the cDNA encoding the interleukin-1 receptor antagonist protein (IL-1Ra) to cultured islets results in protection of human islets in vitro against IL-1beta-induced nitric oxide formation, impairment in glucose-stimulated insulin production, and Fas-triggered apoptosis activation. Our results further support the hypothesis that IL-1beta antagonism in in situ may prevent intra-islet proinsulitic inflammatory events and may allow for an in vivo gene therapy strategy to prevent insulitis and the consequent pathogenesis of diabetes.

Adenoviridae↗

Direct adenovirus-mediated gene transfer of interleukin 1 and tumor necrosis factor alpha soluble receptors to rabbit knees with experimental arthritis has local and distal anti-arthritic effects.

Adenoviral vectors were used to deliver genes encoding a soluble interleukin 1 (IL-1)-type I receptor-IgG fusion protein and/or a soluble type I tumor necrosis factor alpha (TNFalpha) receptor-IgG fusion protein directly to the knees of rabbits with antigen-induced arthritis. When tested individually, knees receiving the soluble IL-1 receptor had significantly reduced cartilage matrix degradation and white blood cell infiltration into the joint space. Delivery of the soluble TNFalpha receptor was less effective, having only a moderate effect on white blood cell infiltration and no effect on cartilage breakdown. When both soluble receptors were used together, there was a greater inhibition of white blood cell infiltration and cartilage breakdown with a considerable reduction of synovitis. Interestingly, anti-arthritic effects were also seen in contralateral control knees receiving only a marker gene, suggesting that sustained local inhibition of disease activity in one joint may confer an anti-arthritic effect on other joints. These results suggest that local intra-articular gene transfer could be used to treat systemic polyarticular arthritides.

Adenoviridae↗

Blocking cytokines with genes.

The pathophysiology of rheumatoid arthritis (RA) is primarily driven by proinflammatory cytokines such as interleukin-1 (IL-1) and tumor necrosis factor alpha. Several biological agents have been identified that effectively block the activity of these cellular messengers, and administration of these agents to animal models of RA and human patients has been found to have therapeutic benefit. The application of gene therapy for the treatment of RA and other articular diseases is being explored to overcome current limitations with delivery of therapeutics to joint tissues. To date, laboratory research has focused on two main areas: (1) evaluation of gene delivery approaches and (2) identification of therapeutic gene products. Considerable progress has been reported with the use of local gene delivery to synovial cells by both in vivo and ex vivo methods and by systemic administration of gene delivery vectors via the circulation. Gene products that have therapeutic efficacy in animal models of RA include: IL-1 receptor antagonist, soluble IL-1 receptor I, soluble tumor necrosis factor receptor II, viral IL-10, and transforming growth factor beta, among others. The success of these laboratory studies has led to the implementation of a Phase I clinical trial to asses the safety and feasibility of using gene therapy in the treatment of RA.

Animals↗