Figure 2: Simplified view of Tregs interacting with other immunocytes at a peripheral lymphoid organ or at a site of inflammation. Known immunocytes (other T cells, monocytes/macrophages, DCs, B lymphocytes) that may interact with Tregs are depicted as well as most candidate interaction molecules. It is now evident that DCs are very important for the maintenance of the regulatory function of Tregs [39,40], and there is evidence that CD8 T regulatory cells as well as B regulatory cells may play a role in the immune circuit [103,104]; neither population is shown here.