Molecular mechanisms underlying lymphocyte-specific cell trafficking into lymph nodes-Functional analysis of genes specifically expressed in high endothelial venules (HEV)

我们成功地从戊型肝炎病毒（HEV）感染的小鼠外周和肠系膜淋巴结中分离出内皮细胞（HEV细胞），并构建了HEV特异性3 '端cDNA文库。然后，我们从每个文库中随机测序了约1，500个cDNA克隆，并将获得的核苷酸序列与类似地从其他组织获得的30个不同cDNA文库中发现的核苷酸序列以及EST数据库中登记的核苷酸序列进行了比较。从这个分析中，我们发现了几个分子选择性表达的戊型肝炎病毒细胞，而不是正常的内皮细胞。它们包括mac 25/TAF/PSF、SGP-2、DARC、富含亮氨酸的α2糖蛋白和Ig-hepta。此外，一些趋化因子如SLC、ELC、BLC、fractalkine、KC和趋化因子在mRNA和蛋白水平上由HEV表达。这些趋化因子，除了KC可以吸引选择性淋巴细胞亚群在体外，因此是战略上有用的招募这些亚群进入淋巴结。此外，与拉霍亚的Minoru教授合作，我们已经成功克隆了一种新的选择性表达于HEV的GlcNAc-6-O-磺基转移酶。这种酶对于形成L-选择素结合糖部分6-磺基唾液酸刘易斯X是必需的，并且可能在L-选择素依赖性淋巴细胞归巢到淋巴结中起关键作用。

We have successfully isolated endothelial cells from HEV (HEV cells) of peripheral and mesenteric lymph nodes of mice and constructed HEV-specific 3'-end cDNA libraries. We then randomly sequenced about 1,500 cDNA clones from each library and compared the obtained nucleotide sequences with those found in 30 different cDNA libraries similarly obtained from other tissues and also with those registered in the EST database. From this analysis, we found several molecules selectively expressed by HEV cells but not normal endothelial cells. They include mac25/TAF/PSF, SGP-2, DARC, leucine-rich α2 glycoprotein and Ig-hepta. In addition, a few chemokines such as SLC, ELC, BLC, fractalkine, KC and lymphotactin are expressed by HEV at mRNA and protein levels. These chemokines except KC can attract selective lymphocyte subsets in vitro, and hence are strategically useful for recruiting these subsets into lymph nodes. In addition, in collaboration with Prof.M.Minoru of La Jolla, we have successfully cloned a novel GlcNAc-6-O-sulfotransferase selectively expressed inHEV.This enzyme is essential for the formation of an L-selectiin binding sugar moiety, 6-sulfo sialyl Lewis X, and is likely to play a crucial role in the L-selectin-dependent lymphocyte homing into lymph nodes.