Glycosaminoglycans interact selectively with chemokines and modulate receptor binding and cellular responses
Glycosaminoglycans interact selectively with chemokines and modulate receptor binding and cellular responses
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DOI：
10.1021/bi990711d
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发表时间：
1999-09-28
期刊：
影响因子：
2.9
通讯作者：
Wells, TNC
中科院分区：
文献类型：
--
作者：
Kuschert, GSV;Coulin, F;Wells, TNC
趋化因子在炎症过程中选择性地募集和激活各种细胞。细胞表面糖胺聚糖（GAG）和趋化因子之间的相互作用驱动趋化因子在炎症部位形成触移性或固定化梯度，从而指导这种募集。趋化因子与人脐静脉内皮细胞（HUVEC）上的糖胺聚糖结合，亲和力在微摩尔范围内：RANTES > MCP-1 > IL-8 > MIP-1 α。这种结合可以被可溶性糖胺聚糖竞争：肝素、硫酸肝素、硫酸软骨素和硫酸皮肤素。RANTES结合显示糖胺聚糖之间最广泛的区别（700倍），而MIP-1 α的选择性最低。在使用硫酸肝素珠作为固定化糖胺聚糖来源的测定中获得了几乎相同的结果。趋化因子与糖胺聚糖片段的结合具有强烈的长度依赖性，并且最佳地需要N-和O-硫酸化。等温滴定量热法数据证实了这些结果; IL-8结合肝素片段的Kd为0.39-2.63 μ M，并且需要5个糖单位来结合趋化因子的每个单体。在来自表达G蛋白偶联趋化因子受体CXCR 1、CXCR 2和CCR 1的细胞的膜中，可溶性GAG抑制趋化因子配体与其受体的结合。与此一致，肝素和硫酸肝素可以抑制IL-8诱导的中性粒细胞钙通量。因此，趋化因子可以与细胞表面和可溶性糖胺聚糖形成复合物;这些相互作用具有不同的功能。可溶性GAG趋化因子复合物不能结合受体，导致生物活性的阻断。以前，我们已经表明，细胞表面糖胺聚糖目前趋化因子的G-蛋白偶联受体，通过增加局部浓度的蛋白质。一个模型，它汇集了所有这些数据。趋化因子-GAG相互作用的选择性表明，选择性破坏趋触梯度可能是炎性疾病中可实现的治疗方法。
Chemokines selectively recruit and activate a variety of cells during inflammation. Interactions between cell surface glycosaminoglycans (GAGs) and chemokines drive the formation of haptotactic or immobilized gradients of chemokines at the site of inflammation, directing this recruitment. Chemokines bind to glycosaminoglycans on human umbilical vein endothelial cells (HUVECs) with affinities in the micromolar range: RANTES > MCP-1 > IL-8 > MIP-1 alpha. This binding can be competed with by soluble glycosaminoglycans: heparin, heparin sulfate, chondroitin sulfate, and dermatan sulfate. RANTES binding showed the widest discrimination between glycosaminoglycans (700-fold), whereas MIP-1 alpha was the least selective. Almost identical results were obtained in an assay using heparin sulfate beads as the source of immobilized glycosaminoglycan. The binding of chemokines to glycosaminoglycan fragments has a strong: length dependence, and optimally requires both N- and O-sulfation. Isothermal titration calorimetry data confirm these results; IL-8 binds heparin fragments with a K-d of 0.39-2.63 mu M, and requires five saccharide units to bind each monomer of chemokine. In membranes from cells expressing the G-protein-coupled chemokine receptors CXCR1, CXCR2, and CCR1, soluble GAGs inhibit the binding of chemokine ligands to their receptors, Consistent with this, heparin and heparin sulfate could inhibit IL-8-induced neutrophil calcium flux. Chemokines can therefore form complexes with both cell surface and soluble GAGs; these interactions have different functions. Soluble GAG chemokines complexes are unable to bind the receptor, resulting in a block of the biological activity. Previously, we have shown that cell surface GAGs present chemokines to the G-protein-coupled receptors, by increasing the local concentration of protein. A model is presented which brings together all of these data. The selectivity in the chemokine-GAG interaction suggests selective disruption of the haptotactic gradient may be an achievable therapeutic approach in inflammatory disease.