Contribution of Mesenteric Lymph Nodes and GALT to the Intestinal Foxp3+ Regulatory T-Cell Compartment

The overall size of the intestinal Foxp3+Treg pool is not impacted significantly by CCR7, mLN, or GALT during the steady-state. However, mLN/GALT appear to contribute to the Foxp3+ pTreg compartment in the SI, particularly in response to soluble oral antigen. These findings highlight important differences in the regulation of intestinal Tregs between the SI and LI, and suggest that enteric antigens may use mLN/GALT to induce Foxp3+ pTreg in the SI, while directly promoting Foxp3+ pTregs in the LI.