| Abstract: | To characterize the role of tumor necrosis factor (TNF)-α in regulating synovial T cell growth, cell cycle progression associated with TNF-α in mitogen-activated synovial T cells of patients with rheumatoid arthritis (RA) were analyzed. After mitogen stimulation, the majority of synovial T cells in RA patients accumulated in S-phase. Anti-human TNF-α monoclonal antibody and soluble recombinant human TNF receptor (rhTNFR) can block S-phase accumulation. Furthermore, synovial fluid (SF) from RA patients was able to inhibit the proliferation of these S-phase-accumulated T cells. These data indicate that TNF-α could regulate activated synovial T cell growth by driving them into S-phase. Combined with the activities of other components of SF, TNF-α seems to play an important role in down-regulating activated synovial T cells in RA patients. In addition, the elevated level of soluble TNFR in the SF of disease-active RA patients is believed to be associated with the promotion of synovial T cell responses. |
