L-selectin-mediated lymphocyte rolling on MAdCAM-1

Abstract

THE L-selectin, a cell surface C-type lectin, directs lymphocyte traffic to lymph nodes¹, and contributes to lymphocyte homing to Peyer's patches^2,3 and to leukocyte interactions with inflamed venules^4,5. Here we report that the mucosal vascular addressin MAdCAM-1, a mucosal endothelial adhesion molecule with immunoglobulin- and mucin-like domains⁶, is a facultative ligand for L-selectin. MAdCAM-1 isolated from mesenteric lymph nodes, but not from cultured endothelioma cells, bears N-glycanase-resistant sialic acid-containing carbohydrate which supports adhesion of L-selectin-transfected lymphoid cells under shear. Interacting lymphoid cells display a 'rolling' behaviour similar to the selectin-dependent rolling of neutrophils observed in inflamed venules. MAdCAM-1 is also a ligand for the lymphocyte integrin homing receptor for Peyer's patches, α4βll (ref. 7), and may be uniquely adapted to support both selectin-mediated lymphocyte rolling and integrin-mediated adhesion and arrest in vivo.