Institute for Hygiene, University of Münster, D-48149 Münster, Germany.
Institute of Infectiology, University of Münster, D-48149 Münster, Germany.
J Lipid Res. 2013 Mar;54(3):692-710. doi: 10.1194/jlr.M031781. Epub 2012 Dec 17.
Glycosphingolipids (GSLs) of the globo-series constitute specific receptors for Shiga toxins (Stxs) released by certain types of pathogenic Escherichia coli strains. Stx-loaded leukocytes may act as transporter cells in the blood and transfer the toxin to endothelial target cells. Therefore, we performed a thorough investigation on the expression of globo-series GSLs in serum-free cultivated Raji and Jurkat cells, representing B- and T-lymphocyte descendants, respectively, as well as THP-1 and HL-60 cells of the monocyte and granulocyte lineage, respectively. The presence of Stx-receptors in GSL preparations of Raji and THP-1 cells and the absence in Jurkat and HL-60 cells revealed high compliance of solid-phase immunodetection assays with the expression profiles of receptor-related glycosyltransferases, performed by qRT-PCR analysis, and Stx2-caused cellular damage. Canonical microdomain association of Stx GSL receptors, sphingomyelin, and cholesterol in membranes of Raji and THP-1 cells was assessed by comparative analysis of detergent-resistant membrane (DRM) and nonDRM fractions obtained by density gradient centrifugation and showed high correlation based on nonparametric statistical analysis. Our comprehensive study on the expression of Stx-receptors and their subcellular distribution provides the basis for exploring the functional role of lipid raft-associated Stx-receptors in cells of leukocyte origin.
糖鞘脂（GSLs）的globoside 系列构成了由某些致病性大肠杆菌菌株释放的志贺毒素（Stxs）的特异性受体。载有 Stx 的白细胞可能在血液中充当转运细胞，并将毒素转移到内皮靶细胞。因此，我们在无血清培养的 Raji 和 Jurkat 细胞中对 globoside 系列 GSLs 的表达进行了彻底研究，分别代表 B 淋巴细胞和 T 淋巴细胞的后代，以及 THP-1 和 HL-60 细胞，分别代表单核细胞和粒细胞谱系。Stx 受体在 Raji 和 THP-1 细胞的 GSL 制剂中的存在以及在 Jurkat 和 HL-60 细胞中的不存在，揭示了固相免疫检测分析与 qRT-PCR 分析中受体相关糖基转移酶表达谱的高度一致性，以及 Stx2 引起的细胞损伤。通过比较密度梯度离心获得的去污剂抗性膜（DRM）和非 DRM 部分，评估了 Raji 和 THP-1 细胞中 Stx GSL 受体、神经鞘磷脂和胆固醇的典型微区缔合，并基于非参数统计分析显示出高度相关性。我们对 Stx 受体的表达及其亚细胞分布的综合研究为探索白细胞来源细胞中脂质筏相关 Stx 受体的功能作用提供了基础。
