Homing receptors on human and rodent lymphocytes--evidence for a conserved carbohydrate-binding specificity.

Lymphocyte recirculation begins with the attachment of circulating cells to the structurally distinctive postcapillary venules of lymphoid organs termed high-endothelial venules (HEVs). In both rodents and humans, the attachment of lymphocytes to the HEVs of peripheral lymph nodes (PNs) on the one hand and gut-associated lymphoid tissues (GALTs) on the other appears to involve discrete adhesive structures on the surfaces of the interacting cells. In rodents, we previously showed that a carbohydrate-binding receptor at the lymphocyte surface participates in the attachment to the HEV of peripheral nodes. The studies reported herein document the involvement of a similar receptor in the selective attachment of human peripheral blood lymphocytes to the HEVs of PNs. We argue that the close functional relationship between the human and rodent receptors indicates that this component of the adhesive interaction has been conserved through evolution.