FIGURE 9.

IL-13 produced from mice adoptively transferred with T_reg cells from Salmonella-CFA/I_IC (AP331)-immunized mice protects against EAE. Cell-sorted 6 × 10⁵ T_reg cells from Salmonella vector (H647)- and AP331-immunized SJL mice were adoptively transferred (i.v.) into naïve SJL recipient mice, and one day later, EAE was induced with PLP_139–151. To neutralize IL-13, rabbit antiserum (0.5 ml) was given one day before EAE induction, and two additional doses (0.25 ml each) were given on days 1 and 5 post-EAE challenge (thick arrows). Equivalent volumes of normal rabbit serum (NRS) were given to control groups. In vivo neutralization of IL-13 of recipient mice given AP331-induced T_reg cells reversed the protection conferred by these T cells, and their clinical scores resembled mice adoptively transferred with H647-induced T_reg cells. Anti-IL-13 treatment had no impact upon EAE in PBS-treated or mice adoptively transferred with T_reg cells from H647-immunized mice. NRS treatments had no negative impact upon the various treated groups. Depicted results are from a total of 5 mice/group. *, P < 0.001, for anti-IL-13 vs. NRS treatment with the adoptively transferred T_reg cell groups; ^†, P < 0.001 for PBS vs. anti-IL-13 and NRS treatment with the adoptively transferred T_reg cell groups.