Discrete Steps in Binding and Signaling of Interleukin-8 with Its Receptor*
Discrete Steps in Binding and Signaling of Interleukin-8 with Its Receptor*
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IL-8 与其受体结合和信号传导的离散步骤*
DOI：
--
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发表时间：
1996
影响因子：
4.8
通讯作者：
S. Qin
中科院分区：
文献类型：
--
作者：
Lijun Wu;N. Ruffing;Xiaojie Shi;W. Newman;D. Soler;C. Mackay;S. Qin
趋化因子结合和通过受体发出信号的机制是复杂的，人们对其知之甚少。在本研究中，我们试图解剖这些过程，并绘制两个CXC趋化因子（白介素-8）受体CXCR1（正式IL-8RA）和CXCR2（正式IL-8RB）的重要功能域，使用受体的阻断单克隆抗体（mab）和CXCR1和CXCR2之间的一系列嵌合体。一组针对CXCR1或CXCR2的特异性单克隆抗体，通过表达这两种受体的转染物免疫小鼠而产生，被证明能有效阻断IL-8和/或生长相关癌基因α (GROα)介导的配体结合、趋化性、弹性蛋白酶释放和CXCR1和CXCR2转染物和/或人中性粒细胞的VCAM-1结合。特别令人感兴趣的是抗cxcr1单抗7D9，它抑制趋化性、弹性蛋白酶释放和VCAM-1结合，但对配体结合没有可检测到的影响。利用一系列CXCR1/2嵌合体抗原和合成肽定位了这些阻断单抗的表位。除7D9外，大部分抗CXCR1抗体定位于氨基酸序列WDFDDL (CXCR1残基10-15)，所有抗CXCR2抗体定位于氨基酸序列FEDFW （CXCR2残基6-10）。mAb 7D9的表位主要涉及CXCR1前45个残基内的一个区域，它似乎是构象敏感的。这些结果支持了IL-8与其受体的结合和信号传导至少在涉及受体不同结构域的两个离散步骤中发生的模型。该模型与以下观点是一致的：配体结合后受体的离散构象变化是触发各种生物反应所必需的。此外，我们还测定了每个CXCR1/2嵌合受体对IL-8和GROα的配体结合和趋化性能。研究发现，它们在赋予IL-8和GROα配体结合和趋化反应的能力方面各不相同，可以得出两个结论。1) CXCR1的n端片段是受体亚型选择性的主要决定因素，这与先前使用兔/人CXCR1/2嵌合体的研究一致；2) GROα在CXCR2中结合的特异性决定因素涉及前15个残基远端的N端序列以及受体的其他部分。
The mechanisms by which chemokines bind and signal through their receptors are complex and poorly understood. In the present study, we sought to dissect these processes and to map important functional domains of the two CXC chemokine (interleukin-8) receptors, CXCR1 (formally IL-8RA) and CXCR2 (formally IL-8RB), using blocking monoclonal antibodies (mAbs) to the receptors and a series of chimeras between CXCR1 and CXCR2. A panel of specific mAbs against CXCR1 or CXCR2, generated by immunizing mice with transfectants expressing either receptor, were shown to effectively block IL-8- and/or growth-related oncogene α (GROα) -mediated ligand binding, chemotaxis, elastase release, and VCAM-1 binding in CXCR1 and CXCR2 transfectants and/or human neutrophils. Of particular interest was an anti-CXCR1 mAb, 7D9, that inhibited chemotaxis, elastase release, and VCAM-1 binding but had no detectable effects on ligand binding. The epitopes of these blocking mAbs were mapped by using a series of CXCR1/2 chimera transfectants and synthetic peptides. Most of the anti-CXCR1 antibodies, except 7D9, mapped to the amino acid sequence WDFDDL (CXCR1 residues 10-15), and all the anti-CXCR2 antibodies mapped to the amino acid sequence FEDFW (CXCR2 residues 6-10). The epitope of mAb 7D9 mainly involved a region within the first 45 residues of CXCR1, and it appeared to be conformation-sensitive. These results support a model in which the binding and signaling of IL-8 with its receptor occur in at least two discrete steps involving distinct domains of the receptor. This model is consistent with the notion that discrete conformational changes of the receptor secondary to ligand binding are required to trigger various biological responses. Moreover, the ligand binding and chemotaxis properties of each CXCR1/2 chimeric receptor to IL-8 and GROα were determined. It was found that each is distinct in its ability to confer ligand binding and chemotactic response to IL-8 and GROα, and two conclusions could be made. 1) The N-terminal segment of CXCR1 is a dominant determinant of receptor subtype selectivity, consistent with previous studies using rabbit/human CXCR1/2 chimeras; and 2) the specificity determinant for GROα binding in CXCR2 involves sequences in the N terminus, distal to the first 15 residues, as well as other parts of the receptor.
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DOI：
10.1016/s0021-9258(18)53442-6
发表时间：
1993-03
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
P. Samama;S. Cotecchia;T. Costa;R. Lefkowitz
通讯作者：
P. Samama;S. Cotecchia;T. Costa;R. Lefkowitz
影响因子：
4.4
作者：
M. Mulligan;M. Jones;M. Bolanowski;M. Baganoff;C. L. Deppeler;D. M. Meyers;U. Ryan;P. Ward
通讯作者：
M. Mulligan;M. Jones;M. Bolanowski;M. Baganoff;C. L. Deppeler;D. M. Meyers;U. Ryan;P. Ward
影响因子：
15.9
作者：
Ponath, PD;Qin, SX;Mackay, CR
通讯作者：
Mackay, CR
在内毒素诱导的胸膜炎兔模型中，IL-8 的中和可抑制中性粒细胞流入。
DOI：
--
发表时间：
1994
期刊：
Journal of immunology (Baltimore, Md. : 1950)
影响因子：
--
作者：
Broaddus,VC;Boylan,AM;Hoeffel,JM;Kim,KJ;Sadick,M;Chuntharapai,A;Hebert,CA
通讯作者：
Hebert,CA