Defining therapeutic targets by using adenovirus: blocking NF-kappaB inhibits both inflammatory and destructive mechanisms in rheumatoid synovium but spares anti-inflammatory mediators.
The role of the transcription factor NF-kappaB in the pathogenesis of rheumatoid arthritis has long been a subject of controversy. We used an adenoviral technique of blocking NF-kappaB through overexpression of the inhibitory subunit IkappaBalpha, which has the advantage that it can be used in the diseased tissue itself, with >90% of the synovial macrophages, fibroblasts, and T cells infected. We found that the spontaneous production of tumor necrosis factor alpha and other pro-inflammatory cytokines is NF-kappaB-dependent in rheumatoid synovial tissue, in contrast to the main anti-inflammatory mediators, like IL-10 and -11, and the IL-1 receptor antagonist. Of even more interest, IkappaBalpha overexpression inhibited the production of matrix metalloproteinases 1 and 3 while not affecting their tissue inhibitor. Blocking NF-kappaB in the rheumatoid joint thus has a very beneficial profile, reducing both the inflammatory response and the tissue destruction. The adenoviral technique described here has widespread applicability, allowing rapid testing of the effects of blocking a potential therapeutic target in either cultures of normal cells or in the diseased tissue itself.
D000256:Adenoviridae / Q000276:immunology*; D000893:Anti-Inflammatory Agents / Q000378:metabolism*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D020672:I-kappa B Proteins; D007249:Inflammation / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D008666:Metalloendopeptidases / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000276:immunology*; D013583:Synovial Membrane / Q000276:immunology*; D013997:Time Factors; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism