Investigation on receptor systems mediating lymphocyte recirculation

为了鉴定淋巴细胞再循环中的分子，特别是淋巴细胞和HE（高内皮）细胞之间的相互作用，我们试图成功地建立培养的细胞系来自大鼠高内皮微静脉（HEV）。然后，我们开发了一种体外试验，以定量淋巴细胞与HE细胞的相互作用，淋巴细胞再循环中最重要的过程。我们已经做了大量的尝试，以产生单克隆抗体（MAb），可以阻止这种异源细胞的相互作用，并随后获得了两个单克隆抗体，其中一个识别大鼠ICAM-1，其他大鼠LFA-1。通过使用上述体外测定，我们研究了LFA-1和ICAM-1分子在淋巴细胞-HEV相互作用中的贡献程度。我们已经证明，（1）LFA-1和ICAM-1在静息淋巴细胞和HEV之间的相互作用中均不起重要作用。（2）当淋巴细胞被激活时，LFA-1依赖的粘附途径开始起作用，尽管依赖于激活程度，ICAM- 1依赖的粘附途径在淋巴细胞和HE细胞之间的相互作用中有差别地使用。进一步的尝试是确定直接参与淋巴细胞-HE细胞相互作用的分子。

In order to identify molecules involved in lymphocyte recirculation, particularly interactions between lymphocytes and HE (high endothelial) cells, we tried successfully to establish cultured cell lines derived from rat high endothelial venules (HEV). We then developed an in vitro assay with which to quantitate lymphocyte interaction with HE cells, a most important process in lymphocyte recirculation. We have made number of attempts to generate monoclonal antibodies (MAb) which can block this heterocellular interaction, and have subsequently obtained two MAb, one of which recognizes the rat ICAM-1, the other the rat LFA-1. By the use of the in vitro assay described above, we investigated the extent of contribution of the LFA-1 and ICAM-1 molecules in lymphocyte-HEV interaction. We have demonstrated that; (1) neither LFA-1 nor ICAM-1 plays a significant role in interaction between resting lymphocytes and HEV, (2) when lymphocytes are activated, LFA-1 dependent adhesion pathways becomes operative, although, depending on the extent of activation, ICAM- 1 dependent adhesion pathway is differentially used in the interaction between lymphocytes and HE cells. Further attempts are being made to identify molecules directly involved in lymphocyte-HE cell interaction.