ABSTRACT
OBJECTIVE: To investigate the effects of retrovirus-based gene delivery of inhibitory cytokines and cytokine inhibitors into human synovial fibroblasts in the SCID mouse model of rheumatoid arthritis (RA). METHODS: The MFG vector was used for gene delivery of tumor necrosis factor alpha receptor (TNFalphaR) p55, viral interleukin-10 (IL-10), and murine IL-10 into RA synovial fibroblasts. The effect on invasion of these cells into human articular cartilage and on perichondrocytic cartilage degradation was examined after 60 days of coimplantation into the SCID mouse. RESULTS: TNFalphaR p55 gene transfer showed only a limited effect on inhibition of RA synovial fibroblast invasiveness and cartilage degradation. In contrast, invasion of the RA synovial fibroblasts into the coimplanted cartilage was strongly inhibited by both viral and murine IL-10. Perichondrocytic cartilage degradation was not affected by either form of IL-10. CONCLUSION: The data show that cytokines can be successfully inserted into the genome of human RA synovial fibroblasts using a retroviral vector delivery system, and that the SCID mouse model of human RA is a valuable tool for examining the effects of gene transfer. In addition, inhibition of more than one cytokine pathway may be required to inhibit both synovial- and chondrocyte-mediated cartilage destruction in RA.
Subject(s)
Antigens, CD/genetics , Arthritis, Rheumatoid/therapy , Gene Transfer Techniques , Interleukin-10/genetics , Moloney murine leukemia virus , Receptors, Tumor Necrosis Factor/genetics , Animals , Arthritis, Rheumatoid/pathology , Cartilage/pathology , Chondrocytes/cytology , Chondrocytes/physiology , DNA Primers , Disease Models, Animal , Fibroblasts/physiology , Fibroblasts/transplantation , Gene Expression , Humans , Lac Operon , Mice , Mice, SCID , Receptors, Tumor Necrosis Factor, Type I , Synovial Membrane/cytology , Synovial Membrane/physiology , Transduction, GeneticABSTRACT
Rheumatoid arthritis (RA) is characterized by progressive destruction of synovial cartilage. In vitro, degradation of cartilage is stimulated by IL-1, a proinflammatory cytokine, which is released from RA synovial fibroblasts (RA-SF). To determine whether gene therapy using the gene encoding the naturally occurring inhibitor of IL-1, IL-1 receptor antagonist (IL-1Ra) is feasible, IL-1 Ra-transduced RA-SF were coimplanted with normal human cartilage in SCID mice. The IL-1 Ra-transduced RA-SF continued to secrete IL-1Ra over a 60-day period. Cartilage that was coimplanted with RA-SF transduced with a marker gene exhibited progressive, chondrocyte-mediated cartilage degradation, whereas no such degradation was observed in cartilage that was coimplanted with RA-SF transduced with IL-1 Ra. Thus, gene therapy using a retrovirus-based gene delivery system appears to be a feasible approach to effectively modifying the local synovial environment.
Subject(s)
Arthritis, Rheumatoid/genetics , Arthritis, Rheumatoid/therapy , Cartilage, Articular/pathology , Gene Transfer Techniques , Receptors, Interleukin-1/genetics , Receptors, Interleukin-1/physiology , Synovial Membrane/immunology , Animals , Arthritis, Rheumatoid/pathology , Cartilage, Articular/immunology , Cartilage, Articular/transplantation , Cells, Cultured , Fibroblasts/immunology , Fibroblasts/transplantation , Humans , Mice , Mice, SCID , Synovial Membrane/pathology , Synovial Membrane/transplantationABSTRACT
Rheumatoid arthritis (RA) has been thought to be largely a T-cell-mediated disease. To evaluate the role of T-cell-independent pathways in RA, we examined the interaction between isolated RA synovial fibroblasts and normal human cartilage engrafted into SCID mice in the absence of T cells and other human cells. The expression of cartilage-de grading enzymes and adhesion molecules was examined by immunohistochemistry and in situ hybridization techniques. The RA synovial fibroblasts invaded the cartilage and kept their transformed appearing cellular shape. They expressed VCAM-1 and produced the cathepsins L and B at the site of invasion. We conclude that RA synovial fibroblasts maintain their invasive and destructive behavior over longer periods of time in the absence of human T cells, indicating that T-cell-independent pathways play a significant role in rheumatoid joint destruction.
