Alon R, Feizi T, Yuen C T, Fuhlbrigge R C, Springer T A
Center for Blood Research, Harvard Medical School, Boston, MA 02115, USA.
J Immunol. 1995 May 15;154(10):5356-66.
Selectin interactions with glycolipids have been examined previously under static conditions, whereas physiologic interactions mediated by selectins take place under flow. We find that under physiologic flow conditions, sialyl Lewis(x) (sLe(x)) glycolipid and sialyl Lewisa (sLe(a)) neoglycolipid support tethering and rolling adhesions of Chinese hamster ovary (CHO) cells expressing E-selectin and lymphoid and myeloid cells expressing L-selectin. These selectin-mediated adhesions persist at the highest shear stresses that occur in postcapillary venules in vivo and occur at lower site densities than found for sLe(x) on neutrophils. The interactions are Ca(2+)-dependent and can be specifically and completely blocked with anti-selectin mAbs. Asialo nonfucosylated glycolipids are inactive, and sulfatide supports weak tethering, but not rolling, of L-selectin-expressing cells. Rolling velocities and resistance to detachment are related to the glycolipid site density and fall within the range measured for neutrophil and myeloid cell rolling on substrates containing purified selectins. These observations are the first indication that glycolipids can interact with selectins in physiologic flow conditions, and can contribute to rolling adhesions.
此前已在静态条件下研究了选择素与糖脂的相互作用，而选择素介导的生理相互作用发生在流动状态下。我们发现，在生理流动条件下，唾液酸化路易斯（x）（sLe（x））糖脂和唾液酸化路易斯a（sLe（a））新糖脂支持表达E-选择素的中国仓鼠卵巢（CHO）细胞以及表达L-选择素的淋巴细胞和髓细胞的系留和滚动黏附。这些选择素介导的黏附在体内毛细血管后微静脉中出现的最高剪切应力下持续存在，且发生的位点密度低于中性粒细胞上sLe（x）的位点密度。这些相互作用依赖于Ca（2+），并且可以被抗选择素单克隆抗体特异性地完全阻断。去唾液酸非岩藻糖基化糖脂无活性，硫脂支持表达L-选择素细胞的弱系留，但不支持滚动。滚动速度和抗脱离能力与糖脂位点密度相关，且落在在含有纯化选择素的底物上中性粒细胞和髓细胞滚动所测量的范围内。这些观察结果首次表明，糖脂可以在生理流动条件下与选择素相互作用，并有助于滚动黏附。
