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
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DOI：
10.4049/jimmunol.165.5.2764
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发表时间：
2000-09-01
影响因子：
4.4
通讯作者：
Bochner, BS
中科院分区：
文献类型：
--
作者：
Davenpeck, KL;Brummet, ME;Bochner, BS
P-选择素糖蛋白配体-I（PSGL-1）是P-选择素的主要配体，组成性表达于循环白细胞表面。本研究的目的是研究白细胞活化对PSGL-1表达以及PSGL-1介导的白细胞与P-选择素粘附的影响，在用血小板活化因子（PAF）和PMA刺激白细胞之前和之后，通过间接免疫荧光和流式细胞术检测PSGL-1的表达。人中性粒细胞、单核细胞和嗜酸性粒细胞在基线时均表现出PSGL-1的显著表面表达，其在暴露于PAF或PMA的几分钟内降低。免疫共沉淀法检测PAF激活的中性粒细胞上清液中PSGL-1的表达。沿着表达数据，这表明PSGL-1从细胞表面去除。在人支气管肺泡灌洗液中也检测到可溶性PSGL-1。EDTA可抑制PSGL-1的下调，但L-选择素脱落抑制剂和其他脱落酶抑制剂不影响PSGL-1的释放，提示PSGL-1可能通过一种未鉴定的脱落酶脱落或通过其他机制被去除。在功能上，PSGL-1下调与中性粒细胞粘附固定P-选择素在静态和流动条件下，最深刻的影响下流动条件下看到的减少。总之，这些数据表明，PSGL-1可以从活化的白细胞表面除去，并且PSGL-1表达的这种降低对白细胞与P-选择素的结合具有深远的影响，特别是在流动条件下。
P-selectin glycoprotein ligand-l (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 Set 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 leukocyte, and that this decrease in PSGL-1 expression has profound effects on leukocyte binding to P-selectin, especially under conditions of flow.