Fig. 1.

Programmatic outline of DC and DC precursor trafficking routes. DCs develop from precursors that originate from primary lymphoid tissues (PLT) such as the BM and the thymus. Precursors and committed DCs enter the circulation and seed peripheral tissues and SLOs (see also Figure 2 for an overview of the hematogenous route). From peripheral tissues, they can access afferent lymph upon receiving a mobilization signal and travel to the draining LN (see also Figure 3 for migration to the draining LN and Figure 4 for migration within the LN). Leukocytes leave LNs via the efferent lymph and are collected in the TD, which eventually guides DCs and their precursors back into the circulation. For individual migratory routes for specific DCs and their precursors refer to table 1.