Location is only part of the story

Gut-associated lymphoid tissue is particularly efficient at generating induced regulatory T cells (iT_reg cells). In Mucosal Immunology, Pabst and colleagues use reciprocal lymph node (LN) transplantation to determine the roles of node-intrinsic and node-extrinsic factors in the generation of iT_reg cells. Gut-draining LNs (mesenteric and celiac) maintain efficient iT_reg cell–generating capacity even when transplanted to the popliteal fossa. Popliteal LNs transplanted to the mesenteries acquire iT_reg cell–generating capacity, suggesting an influence of gut-draining antigens, but they are not as efficient as mesenteric LNs, so node-intrinsic factors must also be important. Depletion studies indicate that cooperation between stromal cells and dendritic cells are critical for the efficient iT_reg cell-generating capacity of gut-draining LNs. Therefore both the position of the LN in the body as well as the inherent properties of the cells in the LN determine its function.

Mucosal Immunol. (14 August 2013) doi:10.1038/mi.2013.54