Immobilized IL-8 triggers progressive activation of neutrophils rolling in vitro on P-selectin and intercellular adhesion molecule-1
Immobilized IL-8 triggers progressive activation of neutrophils rolling in vitro on P-selectin and intercellular adhesion molecule-1
复制标题
DOI：
10.4049/jimmunol.167.7.4017
复制
发表时间：
2001-10-01
影响因子：
4.4
通讯作者：
Lawrence, MB
中科院分区：
文献类型：
--
作者：
DiVietro, JA;Smith, MJ;Lawrence, MB
趋化因子IL-8在血管内皮细胞的管腔侧被发现，在炎症期间它被假定为固定。在这项研究中，我们观察到在静态粘附实验中，固定IL-8可以刺激中性粒细胞牢固地粘附在含有ICAM-1的底物上。然后将可溶性IL-8灌注到在p -选择素（P-sel）和ICAM-1上滚动的中性粒细胞上，证实了溶液中的IL-8可以快速引起滚动的中性粒细胞的停止。为了模拟内皮细胞管腔表面表达IL-8的血管壁，将IL-8与P-sel和ICAM-1一起以确定的位点密度固定在表面。中性粒细胞在P-sel、ICAM-1和IL-8表面平均滚动200 μ m，然后在2 dynes/cm(2)壁剪切应力下通过ICAM-1- β(2)整合素相互作用牢固粘附。将表面上IL-8的密度从60个增加到350个/ μ m(2)，中性粒细胞在牢固粘附之前滚动的平均距离和时间减少了50%。IL-8暴露后，滚动中性粒细胞的icam -1- β(2)整合素相互作用的时间动力学表明存在两类β(2)整合素- icam -1相互作用，与p - self - p -sel糖蛋白配体-1相互作用相比，低强度相互作用的暂停时间增加65%，高强度相互作用的暂停时间比选择素相互作用多400%。根据IL-8位点密度和阻滞时间之间的比例关系，中性粒细胞可能需要对血管壁呈现的临界数量的IL-8分子进行取样，然后才能形成足够数量的高亲切度β(2)整合素键，以实现牢固的粘附。
The chemokine IL-8 is found on the luminal side of vascular endothelial cells, where it is postulated to be immobilized during inflammation. In this study, we observed that immobilized IL-8 can stimulate neutrophils to firmly adhere to a substrate containing ICAM-1 in a static adhesion assay. Soluble IL-8 was then perfused over neutrophils rolling on P-selectin (P-sel) and ICAM-1, confirming that IL-8 in solution can quickly cause rolling neutrophils to arrest. To mimic a blood vessel wall with IL-8 expressed on the luminal surface of endothelial cells, IL-8 was immobilized along with P-sel and ICAM-1 at defined site densities to a surface. Neutrophils rolled an average of 200 mum on surfaces of P-sel, ICAM-1, and IL-8 before firmly adhering through ICAM-1-beta (2) integrin interactions at 2 dynes/cm(2) wall shear stress. Increasing the density of IL-8 from 60 to 350 sites/mum(2) on the surface decreased by 50% the average distance and time the neutrophils rolled before becoming firmly adherent. Temporal dynamics of ICAM-1-beta (2) integrin interactions of rolling neutrophils following IL-8 exposure suggest the existence of two classes of beta (2) integrin-ICAM-1 interactions, a low avidity interaction with a 65% increase in pause times as compared with P-sel-P-sel glycoprotein ligand-1 interactions, and a high avidity interaction with pause times 400% greater than the selectin interactions. Based on the proportionality between IL-8 site density and time to arrest, it appears that neutrophils may need to sample a critical number of IL-8 molecules presented by the vessel wall before forming a sufficient number of high avidity beta (2) integrin bonds for firm adhesion.