Fig. 2.

F241A induces antiinflammatory responses through engagement of type II Fc receptors. (A) C57BL/6 wild-type mice were treated with PBS, IL-4ic, or F241A (0.033 g/kg) and challenged 1 h later with K/BxN sera. Blood was collected from these mice 6 d posttreatment, and IL-6 levels in the sera were analyzed by ELISA. (B) Clinical scores of mice were monitored reflecting the severity of serum-induced arthritis. (C) SIGN-R1^−/− and hDC-SIGN⁺ mice were treated with sialylated wild-type Fc (sFc) or F241A (both 0.033 g/kg) and challenged 1 h later with K/BxN serum. Clinical examination of the mice was conducted daily until day 6 post K/BxN challenge, demonstrating the development and severity of arthritic inflammation. Means ± SEM are plotted; **P < 0.01; ***P < 0.001 determined by Tukey’s post hoc test.