L-selectin ligands expressed by human leukocytes are HECA-452 antibody-defined carbohydrate epitopes preferentially displayed by P-selectin glycoprotein ligand-1.
L-selectin ligands expressed by human leukocytes are HECA-452 antibody-defined carbohydrate epitopes preferentially displayed by P-selectin glycoprotein ligand-1.
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DOI：
10.4049/jimmunol.163.9.5070
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发表时间：
1999-11
影响因子：
4.4
通讯作者：
L. Tu;Patricia G. Murphy;Xuan Li;T. Tedder
中科院分区：
文献类型：
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作者：
L. Tu;Patricia G. Murphy;Xuan Li;T. Tedder
白细胞在炎症部位表达对白细胞-白细胞相互作用至关重要的L-选择素配体。主要的白细胞L-选择素配体是P-选择素糖蛋白配体-1（PSGL-1），其显示用于L-选择素识别的适当的唾液酸刘易斯x（sLex）样碳水化合物决定簇。在人白细胞表达的sLex-like决定簇中，有一个独特的碳水化合物表位，由HECA-452 mAb定义。HECA-452 Ag是由血管内皮细胞表达的L-选择素配体的关键组分。然而，尚未评估HECA-452 Ag在人白细胞L-选择素配体上的表达。在这项研究中，HECA-452 mAb在多个实验系统中阻断了88-99%的中性粒细胞在表达L-选择素的贴壁细胞上滚动或附着。功能阻断性抗PSGL-1 mAb也可抑制89- 98%的L-选择素与中性粒细胞的结合。此外，HECA-452和抗PSGL-1 mAb阻断了大多数P-选择素与中性粒细胞的结合。Western blot分析显示，从中性粒细胞免疫沉淀的PSGL-1显示HECA-452 mAb反应性决定簇，PSGL-1是HECA-452 Ag展示的主要支架。白细胞L-选择素配体也含有硫酸化的决定簇，因为培养配体轴承细胞与NaClO 3废除L-选择素结合。与此一致，人中性粒细胞表达编码与选择素配体生成相关的五种不同磺基转移酶的mRNA：CHST 1、CHST 2、CHST 3、TPST 1和HEC-GlcNAc 6ST。因此，PSGL-1上展示的HECA-452定义的碳水化合物决定簇代表了中性粒细胞表达的主要L-选择素和P-选择素配体。
Leukocytes express L-selectin ligands critical for leukocyte-leukocyte interactions at sites of inflammation. The predominant leukocyte L-selectin ligand is P-selectin glycoprotein ligand-1 (PSGL-1), which displays appropriate sialyl Lewis x (sLex)-like carbohydrate determinants for L-selectin recognition. Among the sLex-like determinants expressed by human leukocytes is a unique carbohydrate epitope defined by the HECA-452 mAb. The HECA-452 Ag is a critical component of L-selectin ligands expressed by vascular endothelial cells. However, HECA-452 Ag expression on human leukocyte L-selectin ligands has not been assessed. In this study, the HECA-452 mAb blocked 88-99% of neutrophil rolling on, or attachment to, adherent cells expressing L-selectin in multiple experimental systems. A function-blocking anti-PSGL-1 mAb also inhibited L-selectin binding to neutrophils by 89-98%. In addition, the HECA-452 and anti-PSGL-1 mAbs blocked the majority of P-selectin binding to neutrophils. Western blot analysis revealed that PSGL-1 immunoprecipitated from neutrophils displayed HECA-452 mAb-reactive determinants and that PSGL-1 was the predominant scaffold for HECA-452 Ag display. Leukocyte L-selectin ligands also contained sulfated determinants since culturing ligand-bearing cells with NaClO3 abrogated L-selectin binding. Consistent with this, human neutrophils expressed mRNA encoding five different sulfotransferases associated with the generation of selectin ligands: CHST1, CHST2, CHST3, TPST1, and HEC-GlcNAc6ST. Therefore, the HECA-452-defined carbohydrate determinant displayed on PSGL-1 represented the predominant L-selectin and P-selectin ligand expressed by neutrophils.