Dynamic expression of L-selectin in cell-to-cell interactions between neutrophils and endothelial cells in vitro.
Neutrophil-endothelial cell interactions are regulated by cell adhesion molecules and their cognate ligands. It has been proposed that L-selectin and Mac-1 (CD11b/CD18), two neutrophil adhesion receptors, have sequential roles in neutrophil extravasation during inflammation. In this model, L-selectin mediates rolling and initial adherence of neutrophils to endothelial cells, while Mac-1 strengthens this initial adherence and also facilitates migration of neutrophils through endothelial cells. L-selectin and Mac-1 expression are known to be inversely regulated. Here an in vitro culture system has been developed to investigate in situ expression of L-selectin during cell-to-cell interactions between neutrophils and endothelial cell monolayers by confocal immunofluorescence analysis. Neutrophils underwent profound cell shape change from round to polarized cell morphology with pseudopod formation after 5 to 15 min coculture with IL-1-stimulated human endothelial cells. L-selectin was redistributed to the pseudopod of the polarized neutrophils in correlation with such cellular changes. During initial cell attachment, neutrophils bound to IL-1-stimulated endothelial cells expressed a high level of L-selectin in a polarized pattern. L-selectin expression decreased over time during neutrophil-endothelial cell interactions.
Liu
Q
Q
Department of Biology, University of Minnesota, Duluth, Minnesota, 55812, USA. qliu1@d.umn.edu
Kishimoto
T K
TK
Mainolfi
E
E
Deleon
R P
RP
Myers
C
C
Moretz
R C
RC
D000328:Adult; D002450:Cell Communication; D048429:Cell Size; D002478:Cells, Cultured; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D019041:L-Selectin / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D013997:Time Factors
D007375:Interleukin-1; D019041:L-Selectin