Picker L J, Warnock R A, Burns A R, Doerschuk C M, Berg E L, Butcher E C
Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235-9072.
Cell. 1991 Sep 6;66(5):921-33. doi: 10.1016/0092-8674(91)90438-5.
LECAM-1 (leukocyte-endothelial cell adhesion molecule 1), the lymphocyte lectin ("selectin") homing receptor for peripheral lymph nodes (PLNs), participates in the earliest interactions of polymorphonuclear neutrophilic leukocytes (PMNs) with inflamed venules. Here, we present evidence that LECAM-1 mediates this function through a novel mechanism--presentation of oligosaccharide ligands to the inducible vascular selectins endothelial-leukocyte adhesion molecule (ELAM-1) and granule membrane protein 140 (GMP-140). PMN, but not lymphocyte, LECAM-1 is modified with the vascular selectin ligand sialyl Lewis x (sLex) and specifically binds ELAM-1-transfected cells. Although only a small fraction of total cell surface sLex, LECAM-1-associated sLex appears to play a prominent role in PMN interactions with cell-associated ELAM-1 and GMP-140, as anti-LECAM-1 monoclonal antibodies or selective removal of cell surface LECAM-1 inhibits PMN binding to vascular selectin transfectants by up to 70%. The enhanced function of LECAM-1-associated sLex may reflect the striking concentration, shown here, of LECAM-1 on PMN surface microvilli, the site of initial cellular contact.
LECAM-1（白细胞-内皮细胞黏附分子1），即外周淋巴结（PLN）的淋巴细胞凝集素（“选择素”）归巢受体，参与多形核中性粒细胞（PMN）与炎症小静脉的最早相互作用。在此，我们提供证据表明，LECAM-1通过一种新机制介导这一功能——向可诱导的血管选择素内皮细胞-白细胞黏附分子（ELAM-1）和颗粒膜蛋白140（GMP-140）呈递寡糖配体。PMN而非淋巴细胞的LECAM-1被血管选择素配体唾液酸化路易斯x（sLex）修饰，并特异性结合转染了ELAM-1的细胞。尽管细胞表面总的sLex中只有一小部分，但与LECAM-1相关的sLex似乎在PMN与细胞相关的ELAM-1和GMP-140的相互作用中起重要作用，因为抗LECAM-1单克隆抗体或选择性去除细胞表面的LECAM-1可使PMN与血管选择素转染体的结合抑制高达70%。与LECAM-1相关的sLex功能增强可能反映了此处所示的LECAM-1在PMN表面微绒毛（初始细胞接触部位）上的显著聚集。
