Identification of a carbohydrate-based endothelial ligand for a lymphocyte homing receptor.
Lymphocyte attachment to high endothelial venules within lymph nodes is mediated by the peripheral lymph node homing receptor (pnHR), originally defined on mouse lymphocytes by the MEL-14 mAb. The pnHR is a calcium-dependent lectin-like receptor, a member of the LEC-CAM family of adhesion proteins. Here, using a soluble recombinant form of the homing receptor, we have identified an endothelial ligand for the pnHR as an approximately 50-kD sulfated, fucosylated, and sialylated glycoprotein, which we designate Sgp50 (sulfated glycoprotein of 50 kD). Recombinant receptor binding to this lymph node-specific glycoprotein requires calcium and is inhibitable by specific carbohydrates and by MEL-14 mAb. Sialylation of the component is required for binding. Additionally, the glycoprotein is precipitated by MECA-79, an adhesion-blocking mAb reactive with lymph node HEV. A related glycoprotein of approximately 90 kD (designated as Sgp90) is also identified.
Imai
Y
Y
Department of Anatomy, University of California, San Francisco 94143-0452.
Singer
M S
MS
Fennie
C
C
Lasky
L A
LA
Rosen
S D
SD
D000818:Animals; D050260:Carbohydrate Metabolism; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000302:isolation & purification / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D008024:Ligands; D008198:Lymph Nodes / Q000502:physiology*; D008214:Lymphocytes / Q000276:immunology / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D008970:Molecular Weight; D016201:Receptors, Lymphocyte Homing / Q000502:physiology*; D013431:Sulfates / Q000378:metabolism; D013462:Sulfur Radioisotopes; D014316:Tritium
D015815:Cell Adhesion Molecules; D008024:Ligands; D016201:Receptors, Lymphocyte Homing; D013431:Sulfates; D013462:Sulfur Radioisotopes; D014316:Tritium