McCarthy D A, Macey M G, Bedford P A, Knight S C, Dumonde D C, Brown K A
School of Biological Sciences, Queen Mary & Westfield College, London, UK.
Immunology. 1997 Oct;92(2):244-51. doi: 10.1046/j.1365-2567.1997.00346.x.
This study investigated whether the high expression of adhesion molecules on enriched preparations of circulating dendritic cells (DCs) was an intrinsic property of the cells or whether it was a consequence of the procedure used to isolate them from blood. Expression of the beta 1, beta 2 integrins (CD11/CD18 family) and other adhesion molecules on DCs in whole blood was compared with that on isolated DCs. Dendritic cells were identified by flow cytometry as leucocytes that were positive for human leucocyte antigen (HLA)-DR, but negative for CD3, CD14, CD16, CD19 and CD56. In contrast to a minority of DCs in whole blood, the majority of isolated DCs expressed the beta 2 integrins and there were a greater number of cells bearing CD44, CD54 and some of the beta 1 integrins (notably CD49b, CD49d, CD49e and CD29). An increase in the proportion of DCs bearing adhesion molecules was generally apparent at the isolation stage when mononuclear cells, which had been incubated overnight, were centrifuged on a metrizamide gradient to enrich for cells of low density. Inclusion of an inhibitor of protein glycosylation and exocytosis (brefeldin A) at all stages of separation partially prevented an increase in the percentage of DCs bearing CD18, C29 and C54 whereas the inclusion of cycloheximide (an inhibitor of polypeptide synthesis) interfered with increases in the percentage of cells bearing CD29 and CD54. Neither of these antagonists had an effect on the intensity of adhesion molecule expression. We suggest that some of the adhesion-dependent functions of isolated DCs are caused, in part, by an upregulation of surface adhesion molecules induced by the enrichment procedure.
本研究调查了循环树突状细胞（DCs）富集制剂上黏附分子的高表达是细胞的固有特性，还是从血液中分离它们所用程序的结果。将全血中DCs上β1、β2整合素（CD11/CD18家族）和其他黏附分子的表达与分离出的DCs上的表达进行了比较。通过流式细胞术将树突状细胞鉴定为人类白细胞抗原（HLA）-DR阳性，但CD3、CD14、CD16、CD19和CD56阴性的白细胞。与全血中少数DCs不同，大多数分离出的DCs表达β2整合素，并且携带CD44、CD54和一些β1整合素（特别是CD49b、CD49d、CD49e和CD29）的细胞数量更多。当过夜孵育的单核细胞在Nycodenz梯度上离心以富集低密度细胞时，在分离阶段，携带黏附分子的DCs比例增加通常很明显。在分离的所有阶段加入蛋白质糖基化和胞吐作用的抑制剂（布雷菲德菌素A）可部分阻止携带CD18、C29和C54的DCs百分比增加，而加入环己酰亚胺（一种多肽合成抑制剂）则会干扰携带CD29和CD54的细胞百分比增加。这两种拮抗剂均对黏附分子表达强度没有影响。我们认为，分离出的DCs的一些黏附依赖性功能部分是由富集程序诱导的表面黏附分子上调引起的。
