TY - JOUR
T1 - Activation of human leukocytes reduces surface P-selectin glycoprotein ligand-1 (PSGL-1, CD162) and adhesion to P-selectin in vitro
AU - Davenpeck, K. L.
AU - Brummet, M. E.
AU - Hudson, S. A.
AU - Mayer, R. J.
AU - Bochner, B. S.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2000/9/1
Y1 - 2000/9/1
N2 - 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 (PAP) 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 PAP or PMA. PSGL-1 was detected in the supernatants of PAP-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.
AB - 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 (PAP) 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 PAP or PMA. PSGL-1 was detected in the supernatants of PAP-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.
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U2 - 10.4049/jimmunol.165.5.2764
DO - 10.4049/jimmunol.165.5.2764
M3 - Article
C2 - 10946308
AN - SCOPUS:0034284237
SN - 0022-1767
VL - 165
SP - 2764
EP - 2772
JO - Journal of Immunology
JF - Journal of Immunology
IS - 5
ER -