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

In this study, we demonstrated that the anti-LeYantibody (BM-1) especially reacted with high endothelial venules (HEVs) in peripheral lymph nodes of blood group O individuals. The LeYexpression on HEVs showed a unique tissue-specific pattern, i.e., a large amount of the LeYexpression 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 LeY-positive HEVs in peripheral lymph nodes and mesenteric lymph nodes. No expression of LeYwas 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-LeYantibody increased after enzyme digestion with α-N-acetylgalactosaminidase or α-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.