Brady H R, Spertini O, Jimenez W, Brenner B M, Marsden P A, Tedder T F
Renal Division, Brigham and Women's Hospital, Harvard Center for the Study of Kidney Diseases, Boston, MA 02115.
J Immunol. 1992 Oct 1;149(7):2437-44.
The role of L-selectin (LAM-1) as a regulator of leukocyte adhesion to kidney microvascular glomerular endothelial cells was assessed in vitro by using L-selectin-directed mAb and an L-selectin cDNA-transfected cell line. The initial attachment of neutrophils, monocytes, and lymphocytes to TNF-activated bovine glomerular endothelial cells was significantly inhibited by the anti-LAM1-3 mAb. Under static conditions, anti-LAM1-3 mAb inhibited neutrophil adhesion by 15 +/- 5%, whereas the anti-LAM1-10 mAb, directed against a functionally silent epitope of L-selectin, was without effect. The binding of a CD18 mAb inhibited adhesion by 47 +/- 6%. In contrast, when the assays were carried out under nonstatic conditions or at 4 degrees C, the anti-LAM1-3 mAb generated significantly greater inhibition (approximately 60%). CD18-dependent adhesion was minimal (approximately 10%) under these conditions. TNF-activated glomerular endothelial cells also supported adhesion of a mouse pre-B cell line transfected with L-selectin cDNA, but not wild-type cells. This process was also inhibited by the anti-LAM1-3 mAb. Leukocyte adhesion to unstimulated endothelial cells was independent of L-selectin, but, after TNF stimulation, L-selectin-mediated adhesion was observed at 4 h, with maximal induction persisting for 24 to 48 h. Leukocyte adhesion was not observed if glomerular endothelial cells were exposed to TNF in the presence of RNA or protein synthesis inhibitors. Leukocyte attachment to TNF-activated glomerular endothelial cells was also partially inhibited by treatment of the cells with mannose-6-phosphate or phosphomannan monoester, a soluble complex carbohydrate, or by prior treatment of glomerular endothelial cells with neuraminidase, suggesting that the glomerular endothelial cell ligand shares functional characteristics with those expressed by lymph node and large vessel endothelial cells. These data suggest that TNF activation induced the biosynthesis and surface expression of a ligand(s) for L-selectin on glomerular endothelial cells, which supports neutrophil, monocyte, and lymphocyte attachment under nonstatic conditions.
通过使用针对L-选择素的单克隆抗体和L-选择素cDNA转染细胞系，在体外评估了L-选择素（LAM-1）作为白细胞与肾微血管肾小球内皮细胞黏附调节因子的作用。抗LAM1-3单克隆抗体显著抑制了中性粒细胞、单核细胞和淋巴细胞对肿瘤坏死因子（TNF）激活的牛肾小球内皮细胞的初始黏附。在静态条件下，抗LAM1-3单克隆抗体抑制中性粒细胞黏附达15±5%，而针对L-选择素功能沉默表位的抗LAM1-10单克隆抗体则无作用。抗CD18单克隆抗体的结合抑制黏附达47±6%。相反，当在非静态条件下或4℃进行测定时，抗LAM1-3单克隆抗体产生的抑制作用显著增强（约60%）。在这些条件下，依赖CD18的黏附作用最小（约10%）。TNF激活的肾小球内皮细胞也支持转染了L-选择素cDNA的小鼠前B细胞系的黏附，但不支持野生型细胞的黏附。这一过程也受到抗LAM1-3单克隆抗体的抑制。白细胞对未刺激的内皮细胞的黏附不依赖于L-选择素，但在TNF刺激后，在4小时时观察到L-选择素介导的黏附，最大诱导持续24至48小时。如果肾小球内皮细胞在存在RNA或蛋白质合成抑制剂的情况下暴露于TNF，则未观察到白细胞黏附。用甘露糖-6-磷酸或磷酸甘露聚糖单酯（一种可溶性复合碳水化合物）处理细胞，或先用神经氨酸酶处理肾小球内皮细胞，也可部分抑制白细胞对TNF激活的肾小球内皮细胞的黏附，这表明肾小球内皮细胞配体与淋巴结和大血管内皮细胞表达的配体具有共同的功能特征。这些数据表明，TNF激活诱导了肾小球内皮细胞上L-选择素配体的生物合成和表面表达，在非静态条件下支持中性粒细胞、单核细胞和淋巴细胞的黏附。
