Three-dimensional distribution of intercellular adhesion molecule-1 on lymphocytes in the high endothelial venule analyzed by backscatter electron imaging.
The intercellular adhesion molecule-1 (ICAM-1) is a ligand for the beta2 integrin. It is present on the vascular endothelium and plays an important role in cell to cell interaction in lymphocyte recirculation. ICAM-1 is expressed not only on the endothelium but also on other cells, especially lymphocytes adhering to the endothelium, B cells and mitogen-stimulated T cells. To define the functional role of ICAM-1 in lymphocytes, the three-dimensional distribution of ICAM-1 on the surface of lymphocytes in the rat mesenteric lymph node HEV was investigated by immunoscanning electron microscopy. ICAM-1 expression was closely associated with variations in surface structures of lymphocytes, which showed a cap-like structure, membrane ruffles and slender microvilli. ICAM-1 was preferentially localized on the cell surface including membrane ruffles (about 90% of all counted gold particles), but rarely on the microvilli (10%). The results suggest that activated lymphocytes with variations in surface structures demonstrate moderate expression and preferential localization of ICAM-1. This seems to enable a three-dimensional interaction of the microvilli of one lymphocyte with the surface membrane of another cell and might be a prerequisite for cluster formation between them, as seen in antigen presentation.
Sasaki
K
K
Department of Anatomy, Yamagata University School of Medicine, Yamagata, Japan.
Okouchi
Y
Y
Rothkötter
H J
HJ
Pabst
R
R
D000818:Animals; D004577:Electron Probe Microanalysis; D004729:Endothelium, Lymphatic / Q000378:metabolism* / Q000648:ultrastructure; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D008198:Lymph Nodes / Q000166:cytology / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D016253:Microscopy, Immunoelectron; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms
D018799:Intercellular Adhesion Molecule-1