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Activation of human leukocytes reduces surface P-selectin glycoprotein ligand-1 (PSGL-1, CD162) and adhesion to P-selectin in vitro
Activation of human leukocytes reduces surface P-selectin glycoprotein ligand-1 (PSGL-1, CD162) and adhesion to P-selectin in vitro
- Source :
- Journal of immunology (Baltimore, Md. : 1950). 165(5)
- Publication Year :
- 2000
-
Abstract
- P-selectin glycoprotein ligand-1 (PSGL-1), the primary ligand for P-selectin, is constitutively expressed on the surface of circulating leukocytes. The objective of this study was to examine the effect of leukocyte activation on PSGL-1 expression and PSGL-1-mediated leukocyte adhesion to P-selectin. PSGL-1 expression was examined via indirect immunofluorescence and flow cytometry before and after leukocyte stimulation with platelet activating factor (PAF) and PMA. Human neutrophils, monocytes, and eosinophils were all demonstrated to have significant surface expression of PSGL-1 at baseline, which decreased within minutes of exposure to PAF or PMA. PSGL-1 was detected in the supernatants of PAF-activated neutrophils by immunoprecipitation. Along with the expression data, this suggests removal of PSGL-1 from the cell surface. Soluble PSGL-1 was also detected in human bronchoalveolar lavage fluids. Down-regulation of PSGL-1 was inhibited by EDTA. However, inhibitors of L-selectin shedding and other sheddase inhibitors did not affect PSGL-1 release, suggesting that PSGL-1 may be shed by an as yet unidentified sheddase or removed by some other mechanism. Functionally, PSGL-1 down-regulation was associated with decreased neutrophil adhesion to immobilized P-selectin under both static and flow conditions, with the most profound effects seen under flow conditions. Together, these data indicate that PSGL-1 can be removed from the surface of activated leukocytes, and that this decrease in PSGL-1 expression has profound effects on leukocyte binding to P-selectin, especially under conditions of flow.
- Subjects :
- P-selectin
Neutrophils
Immunology
Down-Regulation
Cell Separation
Biology
Ligands
Bronchial Provocation Tests
Monocytes
Neutrophil Activation
Flow cytometry
chemistry.chemical_compound
medicine
Cell Adhesion
Leukocytes
Immunology and Allergy
Humans
Enzyme Inhibitors
L-Selectin
Platelet Activating Factor
Edetic Acid
chemistry.chemical_classification
Membrane Glycoproteins
integumentary system
Platelet-activating factor
medicine.diagnostic_test
Adhesion
Sheddase
Allergens
Molecular biology
In vitro
Asthma
Eosinophils
P-Selectin
chemistry
Solubility
Pollen
Tetradecanoylphorbol Acetate
P-selectin glycoprotein ligand-1
Glycoprotein
Rheology
Bronchoalveolar Lavage Fluid
Subjects
Details
- ISSN :
- 00221767
- Volume :
- 165
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Accession number :
- edsair.doi.dedup.....8a25ceb684a58e4b057ac5e083cd1a24