Fig. 1.

Adoptive transfer of Salmonella-CFA/I-induced CD25⁺CD4⁺ T cells confers protection against EAE, but is abrogated upon in vivo neutralization of TGF-β. CD25⁺CD4⁺ and CD25⁻CD4⁺ T cells obtained from mice previously orally immunized with Salmonella-CFA/I (strain H696) or Salmonella vector (strain H647) were adoptively transferred into naive SJL mice. A, Schematic of adoptive transfer, EAE challenge with PLP_139–151, and in vivo neutralization with anti-TGF-β mAb or isotype MOPC 21 IgG1 control Ab is shown; PT, pertussis toxin. EAE clinical scores following adoptive transfer, EAE challenge, and in vivo treatment with IgG1 Ab or anti-TGF-β mAb of recipients given B,C, CD25⁺CD4⁺ and CD25⁻ CD4⁺ T cells (purity plots in inset) from H696-immunized mice; and D, E, CD25⁺CD4⁺ and CD25⁻ CD4⁺ T cells (purity plots in inset) from H647-immunized mice are shown. Data depict mean clinical scores combined from three experiments: *, p < 0.001; **, p < 0.05 versus PBS/IgG1or PBS/α-TGF-β mAb-treated mice; ⁺, p < 0.001; ⁺⁺, p < 0.05 for CD25⁺ versus CD25⁻.