Plasmin reduces human T cell arrest on endothelial-like cells by cleaving bound CCL21 from the cell surface.

CCL21 is a key homeostatic chemokine best known for its role in lymphocyte homing and compartmentalization in the lymph node. CCL21 also plays a role in trans-endothelial migration and is known to be bound to the surface of endothelial cells in high endothelial venules and inflamed tissues. The effects of CCL21 are highly dependent on its form; full-length CCL21 can bind to the surface of endothelial cells and induce lymphocyte arrest and transendothelial migration, whereas truncated CCL21 cannot.