Afferent lymph-derived T cells and dendritic cells use different CCR7-dependent routes for lymph node entry and intranodal migration

Overview & Synopsis

By establishing micromanipulator-guided injections into afferent lymph vessels of the popliteal lymph node (LN) in living mice, we demonstrate, using two-photon microscopy, that lymph-derived T cells entered LN parenchyma primarily from peripheral medullary sinuses while dendritic cells (DCs) transmigrated through the floor of the afferent side subcapsular sinus. Transmigrating DCs induced local changes of the subcapsular sinus floor thereby allowing the concomitant entry of T cells at these sites. Signals mediated by the chemokine receptor CCR7 were absolutely required for the directional migration of both DC and T cells into the T cell zone but were dispensable for parenchymal entry of lymph-derived T cells and dendrite probing of DC.