Ager A, Mistry S
Department of Cell and Structural Biology, University of Manchester, GB.
Eur J Immunol. 1988 Aug;18(8):1265-74. doi: 10.1002/eji.1830180818.
The interaction between lymphocytes and cultured high endothelial venule endothelium has been studied using light and electron microscopy. High endothelial cells (HEC) in monolayer culture bound lymphocytes 15-200-fold more efficiently than aortic endothelium, aortic fibroblasts or serum-coated glass. Light microscopy of lymphocytes bound to HEC showed two populations. Type I lymphocytes were phase-light, round and revealed no intracellular detail. Type II lymphocytes were phase-dark and flattened. The nucleus and cytoplasm of type II cells were clearly visible under high power light microscopy. The relative positions of these two populations were determined by electron microscopy. Type I lymphocytes were attached to the surface of HEC and type II lymphocytes were flattened underneath. The transition from type I to type II was accompanied by a loss of surface microvilli and a redistribution of intracellular organelles. This suggested that lymphocytes actively migrated across the HEC layer in this assay. The relationship between migrated lymphocytes and total adherent cells was determined by analysis of surface phenotype. Lymphocytes did not adhere randomly from the cell population plated. After 60 min there was an enrichment for B over T lymphocytes and the adherent T cell population was itself enriched for CD8+ cells over CD4+ cells. Migrated cells were, however, a random subpopulation of lymphocytes which adhered to HEC. This is clear evidence that migration was preceded by specific binding to HEC. Lymphocyte adhesion was independent of viable HEC showing that it was a passive event on the part of the endothelium. Lymphocyte migration was, however, completely dependent on viable high endothelium. We conclude that cultured HEC provide a biologically relevant, 3-dimensional matrix which supports the specific adhesion of lymphocytes and actively promotes lymphocyte migration. These observations suggest to us that cultured high endothelium provides a novel in vitro model for the study of lymphocyte migration into lymph nodes from the blood.
利用光学显微镜和电子显微镜研究了淋巴细胞与培养的高内皮微静脉内皮之间的相互作用。单层培养的高内皮细胞（HEC）结合淋巴细胞的效率比主动脉内皮、主动脉成纤维细胞或血清包被的玻璃高15 - 200倍。光学显微镜观察到与HEC结合的淋巴细胞有两类。I型淋巴细胞在相差显微镜下呈亮相、圆形，细胞内细节不明显。II型淋巴细胞在相差显微镜下呈暗相且扁平。在高倍光学显微镜下可清晰看到II型细胞的细胞核和细胞质。通过电子显微镜确定了这两类细胞的相对位置。I型淋巴细胞附着于HEC表面，II型淋巴细胞则在其下方扁平铺展。从I型到II型的转变伴随着表面微绒毛的丧失和细胞内细胞器的重新分布。这表明在该实验中淋巴细胞能主动穿过HEC层。通过分析表面表型确定了迁移淋巴细胞与总黏附细胞之间的关系。淋巴细胞并非从接种的细胞群体中随机黏附。60分钟后，B淋巴细胞相对于T淋巴细胞有所富集，并且黏附的T细胞群体中CD8 +细胞相对于CD4 +细胞也有所富集。然而，迁移的细胞是黏附于HEC的淋巴细胞的随机亚群。这清楚地证明迁移之前淋巴细胞与HEC发生了特异性结合。淋巴细胞黏附不依赖于活的HEC，表明这是内皮细胞的被动事件。然而，淋巴细胞迁移则完全依赖于活的高内皮。我们得出结论，培养的HEC提供了一种生物学相关的三维基质，它支持淋巴细胞的特异性黏附并积极促进淋巴细胞迁移。这些观察结果表明，培养的高内皮为研究淋巴细胞从血液迁移到淋巴结提供了一种新的体外模型。
