Expression of interleukin-12 in synovial tissue from patients with rheumatoid arthritis.

点击翻译按钮获取中文摘要

The importance of interleukin-12 as a factor in the interferon-gamma (IFN-gamma) -dominant T cell cytokine response in the synovial tissue of patients with rheumatoid arthritis (RA) was examined. Synovial tissues from RA patients more strongly expressed IL-12 p40 mRNA than did osteorthritis (OA) tissues, as determined by RT-PCR.Dissociated tissue cells from RA patients sspontaneously released detectable amounts of IL-12 p70 in culture, whereas production of IL-12 by OA tissues was limited. By immunohistochemical analysis, IL-12-producing cells were localized mainly in the sublining layr of RA synovium, and mostly expressed the CD68 antigen. Levels of IFN-gamma production by RA synovial tissue cells were potently and selectively enhanced by IL-12. The ability of IL-2-expanding synovial T cells to produce IFN-gamma was augmented by costimulation with IL-12 and diminished by anti-IL-12, while it was not affected by IL-4. These dada suggest that IL-12, produced mainly by macrophage-lineage cells, may be involved in IFN-gamma dominant cytokine production by infiltrating T cells in joints with chronic RA.