Induction of collagen-induced arthritis
Native chicken CII was obtained from Sigma-Aldrich (St. Louis, MO). CII was dissolved in 0.01 M acetic acid and emulsified in Complete Freund’s Adjuvant (CFA). CFA was prepared by mixing 5 mg heat-killed Mycobacterium tuberculosis (H37Ra; Difco Laboratories, Detroit, MI) and 1 mL Incomplete Freund’s Adjuvant (Sigma-Aldrich). Mice were immunized intradermally at the base of the tail with 200 mg of CII in CFA on days 0 and 21. Arthritis was evaluated visually, and changes in each paw were scored on a scale of 0 to 3 as follows; 0 = normal, 1 = slight swelling and/or erythema, 2 = pronounced swelling, 3 = ankylosis. The score was summed-up for each limb (maximum score = 12).