Oral Salmonella vaccination enhances the percentage of Treg cells expressing FoxP3 in both the mucosal and systemic compartments. A, CLN lymphocytes taken from SJL mice 14 days after EAE challenge (treated with H696, H647, or PBS 6 days postchallenge) and were examined by FACS for the presence of CD25+CD4+ T cells. Each group showed stimulation of Treg cells, but mice treated with H647 or H696 had increased numbers, and these were >90% FoxP3+. B, A kinetic analysis was performed on spleen, MLN, PP, SMLN, and deep CLN. Increases in FoxP3+ Treg cells were observed for Salmonella-treated groups. *, p < 0.001 for PBS vs H647 and PBS vs H696. C and D, Oral vaccination with H696 only (no PLP139–151 challenge) results in FoxP3+ Treg cells in spleen, MLN, PP, SMLN, and (C and D) CLN peaking ~2 wk after immunization (mean of five mice per group ± SEM).