Tissue-specific expression of Le(Y) antigen in high endothelial venules of human lymphoid tissues.

In this study, we demonstrated that the anti-Le(Y) antibody (BM-1) especially reacted with high endothelial venules (HEVs) in peripheral lymph nodes of blood group O individuals. The Le(Y) expression on HEVs showed a unique tissue-specific pattern, i.e., a large amount of the Le(Y) expression in peripheral lymph nodes and no or small amounts in mesenteric lymph node. Statistical analysis showed that there was the significant difference between the percentage of Le(Y)-positive HEVs in peripheral lymph nodes and mesenteric lymph nodes. No expression of Le(Y) was observed in vessels of Payer's patch, thymus, spleen and other non-lymphoid organs. In blood group A or B individuals, the reactivity between HEVs and anti-Le(Y) antibody increased after enzyme digestion with alpha-N-acetylgalactosaminidase or alpha-galactosidase. These findings show that the expression of difucosylated blood group ABH antigens are especially expressed on HEVs in peripheral lymph nodes. Furthermore, the tissue-specific pattern suggests that these antigens may be related to intercellular adhesion between lymphocytes and HEVs.