A 4-trifluoromethyl analogue of celecoxib inhibits arthritis by suppressing innate immune cell activation

To induce collagen-induced arthritis (CIA), DBA1/J mice were immunized with bovine type II collagen (CII) in Freund's adjuvant. Collagen antibody-induced arthritis (CAIA) was induced in C57BL/6 mice by injecting anti-CII antibodies. Mice received 10 μg/g of TFM-C or celecoxib every other day. The effects of TFM-C on clinical and histopathological severities were assessed. The serum levels of CII-specific antibodies were measured by ELISA. The effects of TFM-C on mast cell activation, cytokine producing capacity by macophages, and neutrophil recruitment were also evaluated.TFM-C inhibited the severity of CIA and CAIA more strongly than celecoxib. TFM-C treatments had little effect on CII-specific antibody levels in serum. TFM-C suppressed the activation of mast cells in arthritic joints. TFM-C also suppressed the production of inflammatory cytokines by macrophages and leukocyte influx in thioglycollate-induced peritonitis.These results indicate that TFM-C may serve as an effective new disease-modifying drug for treatment of arthritis, such as rheumatoid arthritis.In the past decade, a series of potent new biologic therapeutics have demonstrated remarkable clinical efficacy in several autoimmune diseases, including rheumatoid arthritis (RA). In the case of RA, a chronic progressive autoimmune disease that targets joints and occurs in approximately 0.5 to 1% of adults, biologic agents, such as TNF inhibitors, have proven effective in patients not responding to disease-modifying anti-rheumatic drugs, such as methotrexate. However, about 30% of patients treated with a TNF inhibitor are primary non-responders. Moreover, a substantial proportion of patients experience a loss of efficacy after a primary response to a TNF inhibitor (secondary non-responders) [1-3]. More recently, as new therapies have become available, including biological agents targeting IL-6, B cells and T cells, it has become clear that a notable proportion of patients respond to these new biological age