Spatial distribution of L-selectin (CD62L) on human lymphocytes and transfected murine L1-2 cells.
We have examined the topographical distribution of L-selectin on surface membrane domains of human lymphocytes and murine L1-2 cells transfected to express human L-selectin. L-selectin was immunolocalized using murine monoclonal DREG 200 Fab antibody and a 12 nm colloidal gold-conjugated secondary antibody. Cell surface morphology and surface distribution of gold-labelled L-selectin were visualized using backscatter electron images obtained by high-resolution, field emission scanning electron microscopy. The topographical morphologies of lymphocytes of both types were complex. The surface of human lymphocytes was composed of both microvilli and ruffles; that of the murine cells was composed of long microvilli and few, if any, ruffles. L-selectin on human lymphocytes was observed primarily as focal clusters on the apical surfaces of ruffles and microvilli. Similarly, on the transfected murine cells, L-selectin was detected predominantly on the apical surface of microvilli. We conclude that L-selectin has a common spatial distribution and clustered organization on all leukocytes examined to-date, and that these features of receptor expression likely facilitate rolling of circulating leukocytes on the endothelial surface.
Hasslen
S R
SR
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, USA.
von Andrian
U H
UH
Butcher
E C
EC
Nelson
R D
RD
Erlandsen
S L
SL
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D019041:L-Selectin / Q000032:analysis* / Q000235:genetics; D008214:Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D008855:Microscopy, Electron, Scanning; D014162:Transfection
D019041:L-Selectin