Brazil Jennifer C, Sumagin Ronen, Stowell Sean R, Lee Goo, Louis Nancy A, Cummings Richard D, Parkos Charles A
Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA;
Department of Pathology, Emory University, Atlanta, Georgia, USA.
J Leukoc Biol. 2017 Sep;102(3):753-762. doi: 10.1189/jlb.1MA0117-013R. Epub 2017 Jun 9.
PMN-expressed fucosylated glycans from the Lewis glycan family, including Lewis-x (Le) and sialyl Lewis-x (sLe), have previously been implicated in the regulation of important PMN functions, including selectin-mediated trafficking across vascular endothelium. Although glycans, such as Le and sLe, which are based on the type 2 sequence (Galβ1-4GlcNAc-R), are abundant on PMNs, the presence of type 1 Galβ1-3GlcNAc-R glycans required for PMN expression of the closely related stereoisomer of Le, termed Lewis-A (Le), has not, to our knowledge, been reported. Here, we show that Le is abundantly expressed by human PMNs and functionally regulates PMN migration. Using mAbs whose precise epitopes were determined using glycan array technology, Le function was probed using Le-selective mAbs and lectins, revealing increased PMN transmigration across model intestinal epithelia, which was independent of epithelial-expressed Le Analyses of glycan synthetic machinery in PMNs revealed expression of β1-3 galactosyltransferase and α1-4 fucosyltransferase, which are required for Le synthesis. Specificity of functional effects observed after ligation of Le was confirmed by failure of anti-Le mAbs to enhance migration using PMNs from individuals deficient in α1-4 fucosylation. These results demonstrate that Le is expressed on human PMNs, and its specific engagement enhances PMN migration responses. We propose that PMN Le represents a new target for modulating inflammation and regulating intestinal, innate immunity.
来自路易斯聚糖家族的中性粒细胞表达的岩藻糖基化聚糖，包括路易斯-x（Le）和唾液酸路易斯-x（sLe），先前已被认为参与调节重要的中性粒细胞功能，包括选择素介导的跨血管内皮运输。尽管基于2型序列（Galβ1-4GlcNAc-R）的聚糖，如Le和sLe，在中性粒细胞上大量存在，但据我们所知，与Le紧密相关的立体异构体路易斯-A（Le）的中性粒细胞表达所需的1型Galβ1-3GlcNAc-R聚糖的存在尚未见报道。在此，我们表明Le在人中性粒细胞中大量表达并在功能上调节中性粒细胞迁移。使用通过聚糖阵列技术确定其精确表位的单克隆抗体，利用Le选择性单克隆抗体和凝集素探究Le的功能，结果显示中性粒细胞跨模型肠上皮的迁移增加，这与上皮表达的Le无关。对中性粒细胞中聚糖合成机制的分析揭示了Le合成所需的β1-3半乳糖基转移酶和α1-4岩藻糖基转移酶的表达。使用来自α1-4岩藻糖基化缺陷个体的中性粒细胞，抗Le单克隆抗体未能增强迁移，从而证实了Le连接后观察到的功能效应的特异性。这些结果表明Le在人中性粒细胞上表达，其特异性结合增强了中性粒细胞迁移反应。我们提出中性粒细胞Le代表了调节炎症和调节肠道固有免疫的新靶点。
