Hendriks H R, Duijvestijn A M, Kraal G
Department of Cell Biology, Medical Faculty, Free University, Amsterdam, The Netherlands.
Eur J Immunol. 1987 Dec;17(12):1691-5. doi: 10.1002/eji.1830171203.
Occlusion of the afferent lymph flow to the lymph node (LN) results in both flattening of the endothelium of high endothelial venules (HEV) and a severe decrease in numbers of lymphocytes in transit across the walls of the flattened HEV. In the present study we have used the in vitro lymphocyte-binding assay to investigate the ability of HEV in rat LN to bind lymphocytes at various time points after occlusion of the afferent lymph flow. In addition the specificity of T and B lymphocyte adherence to HEV of such operated LN was studied. In normal LN, lymphocytes adhered to virtually all HEV using the in vitro binding assay. However, 1 and 2 weeks after operation lymphocytes bound to only 50-60% of the HEV and by 3-6 weeks 20-30%. The total numbers of lymphocytes bound to these HEV had also diminished to 10% of the control value 3-6 weeks after operation. Morphometric analysis showed that this was not only due to a reduction in the area of HEV endothelium available for lymphocyte adherence by flattening of the high endothelial cells, but also to a strong decrease in the numbers of bound lymphocytes per unit area high endothelium. In spite of the reduction in numbers of adhering lymphocytes the T/B cell ratio did not change. The results show that the reduction in lymphocyte binding of HEV in operated LN is a rapid event, probably due to loss of high endothelial cell determinants involved in binding of lymphocytes. The decrease in lymphocyte binding clearly precedes flattening of HEV endothelium suggesting that the height of high endothelial cells is of secondary importance to lymphocyte adherence.
阻断淋巴结（LN）的输入淋巴流会导致高内皮微静脉（HEV）的内皮细胞变扁平，并且穿过扁平HEV壁迁移的淋巴细胞数量严重减少。在本研究中，我们使用体外淋巴细胞结合试验来研究大鼠LN的HEV在阻断输入淋巴流后不同时间点结合淋巴细胞的能力。此外，还研究了此类手术处理的LN中T和B淋巴细胞黏附于HEV的特异性。在正常LN中，使用体外结合试验时，淋巴细胞几乎黏附于所有HEV。然而，手术后1周和2周，淋巴细胞仅与50%-60%的HEV结合，到3-6周时，这一比例为20%-30%。手术后3-6周，与这些HEV结合的淋巴细胞总数也降至对照值的10%。形态计量分析表明，这不仅是由于高内皮细胞变扁平导致可供淋巴细胞黏附的HEV内皮面积减少，还由于每单位面积高内皮上结合的淋巴细胞数量大幅减少。尽管黏附淋巴细胞的数量减少，但T/B细胞比例并未改变。结果表明，手术处理的LN中HEV淋巴细胞结合能力的降低是一个快速事件，可能是由于参与淋巴细胞结合的高内皮细胞决定簇丢失所致。淋巴细胞结合能力的降低明显先于HEV内皮细胞变扁平，这表明高内皮细胞的高度对淋巴细胞黏附来说是次要的。
