Rheumatoid arthritis (RA) is an autoimmune disease in which immune cells attack a bone, and finally joint functions are lost. In this study, we analyzed cytokine expression patterns which are relevant to RA (Experiment 1) and effects of anti-mouse TNF-α antibody (Experiment 2) in CIA (collagen-induced arthritis) mice. CIA was induced by immunizing DBA mice with type II collagen/Adjuvant (CFA or IFA) on day 0 (primary sensitization) and 21 (secondary sensitization). In experiment 1, the joint of tarsi of the hind limb were collected at 14 time points during day 0 and 49 and the expression of cytokines was measured with CBA assay and real time PCR. In experiment 2, the expression of cytokines at day 49 was measured following administration of anti-mouse TNF-α antibody intraperitoneally 3 times per week after the secondary immunization.
The results of the present experiment 1 showed that cytokines expression (IL-1β, TNF-α, IL-6) was peaked at day 31 to 38. Treatment with anti-mouse TNF-α antibody significantly decreased the expression of these cytokines compared with the vehicle group (Experiment 2). Thus, it is considered that our experiment system used in this study is useful for investigation of RA therapeutic drugs.