Crutchfield K L, Shinde Patil V R, Campbell C J, Parkos C A, Allport J R, Goetz D J
Department of Biomedical Engineering, The University of Memphis, Tennessee, USA.
J Leukoc Biol. 2000 Feb;67(2):196-205. doi: 10.1002/jlb.67.2.196.
Neutrophils can attach to E-selectin under flow. Proposed ligands for E-selectin carry SLe(x)-type glycans. The leukocyte beta2 integrins are glycosylated with SLe(x). Thus, we speculated that beta2 integrins could support attachment to E-selectin. To test this hypothesis, we coated 10-microm-diameter microspheres with purified CD11b/CD18 (alphaMbeta2) and investigated the adhesion of the resulting alphaMbeta2 microspheres to E-selectin. Under in vitro flow conditions, the alphaMbeta2 microspheres attached to Chinese hamster ovary cells expressing E-selectin (CHO-E) and 4-h interleukin-1beta-activated human umbilical vein endothelial cells (HUVEC). At a shear stress of 1.8 dynes/cm2, the attachment events were eliminated by pretreatment of the cellular monolayers with a mAb to E-selectin. alphaMbeta2 microspheres did not attach to untransfected CHO cells or unactivated HUVEC at 1.8 dynes/cm2. Taken together, the results strongly suggest that the CD11b/CD18-E-selectin bond has sufficient biophysical properties to mediate attachment of neutrophil-sized particles to E-selectin under flow.
中性粒细胞在流动状态下可与E-选择素结合。E-选择素的潜在配体带有SLe(x)型聚糖。白细胞β2整合素被SLe(x)糖基化。因此，我们推测β2整合素可能支持与E-选择素的结合。为验证这一假设，我们用纯化的CD11b/CD18（αMβ2）包被直径为10微米的微球，并研究所得αMβ2微球与E-选择素的黏附情况。在体外流动条件下，αMβ2微球可与表达E-选择素的中国仓鼠卵巢细胞（CHO-E）以及经4小时白细胞介素-1β激活的人脐静脉内皮细胞（HUVEC）结合。在剪切应力为1.8达因/平方厘米时，用抗E-选择素单克隆抗体预处理细胞单层可消除黏附事件。在1.8达因/平方厘米时，αMβ2微球不与未转染的CHO细胞或未激活的HUVEC结合。综上所述，结果强烈表明CD11b/CD18-E-选择素键具有足够的生物物理特性，可介导中性粒细胞大小的颗粒在流动状态下与E-选择素的结合。
