PT - JOURNAL ARTICLE AU - Shyjan, A M AU - Bertagnolli, M AU - Kenney, C J AU - Briskin, M J TI - Human mucosal addressin cell adhesion molecule-1 (MAdCAM-1) demonstrates structural and functional similarities to the alpha 4 beta 7-integrin binding domains of murine MAdCAM-1, but extreme divergence of mucin-like sequences. DP - 1996 Apr 15 TA - The Journal of Immunology PG - 2851--2857 VI - 156 IP - 8 4099 - http://www.jimmunol.org/content/156/8/2851.short 4100 - http://www.jimmunol.org/content/156/8/2851.full SO - J. Immunol.1996 Apr 15; 156 AB - The mucosal vascular addressin, mucosal addressin cell adhesion molecule-1 (MAdCAM-1), is an Ig family adhesion receptor preferentially expressed by venular endothelial cells at sites of lymphocyte extravasation in murine mucosal lymphoid tissues and lamina propria. MAdCAM-1 specifically binds both human and mouse lymphocytes that express the homing receptor for Peyer's patches, the integrin alpha 4 beta 7. Functional expression cloning was used to isolate a cDNA from a macaque mesenteric lymph node library that encodes the homologue to murine MAdCAM-1. The macaque cDNA was subsequently used to clone the human homologue as well. Expression of human MAdCAM-1 RNA is restricted to mucosal tissues, gut-associated lymphoid tissues and spleen. Human MAdCAM-1 selectively binds both murine and human lymphocyte cell lines expressing alpha 4 beta 7. Human and macaque MAdCAM-1 have two Ig-like domains that are similar to the two amino-terminal integrin binding domains of murine MAdCAM-1. The conservation of sequences within the region homologous to the mucin/IgA domain of murine MAdCAM-1 is, however, much less apparent. These receptors exhibit considerable variation from murine MAdCAM-1 with respect to the length of the mucin-like sequence and the lack of a membrane proximal Ig (IgA-like) domain. The isolation of these different species of MAdCAM-1 demonstrates greater seleoffctive pressure for maintenance of amino acids involved in alpha 4 beta 7 binding than those sequences presumably involved in the presentation of carbohydrates for selectin binding.