Fig. 7.
IVIG/F241A induces Treg-cell activation by signaling through the IL-33/ST2 axis. (A and B) C57BL/6 wild-type mice were treated with PBS or IVIG (1 g/kg) and then challenged with K/BxN serum. To block IL-33 signaling, mice received an anti-ST2 blocking antibody (100 µg i.v.) or isotype control. Clinical scores of rheumatoid arthritis are shown (A). On day 5 post disease induction, mice were killed and splenic Treg cells were analyzed by flow cytometry (B). (C) EAE was induced in C57BL/6 wild-type mice by immunization with MOG35–55 peptide. Mice were treated i.v. with PBS or nonsialylated F241A (0.033 g/kg) four times, on days 5, 10, 15, and 20. Each injection was preceded by an i.v. injection of an anti-ST2 blocking antibody. Shown are clinical scores of EAE. (D) EAE mice were killed and cells were isolated from draining lymph nodes. Treg cells and their Foxp3 and ST2 expression was analyzed by flow cytometry. Means ± SEM are plotted; *P < 0.05; ***P < 0.001 determined by Tukey’s post hoc test.