Glycosylation might provide endothelial zip codes for organ-specific leukocyte traffic into inflammatory sites.

Inflammatory diseases are characterized by the leukocyte infiltration into tissues. L-selectin on lymphocytes and its endothelial glycosylated ligands are instrumental in the initiation of lymphocyte extravasation. Immunohistochemical stainings with monoclonal antibodies against functionally active glycan-decorated L-selectin ligands, ie, sialyl-Lewis x (sLex, 2F3, and HECA-452) or sulfated extended core 1 lactosamine (MECA-79), were performed on more than 400 specimen representatives for thyroiditis, myocarditis, psoriasis, vasculitis, ulcerative colitis, and their corresponding noninflamed tissues. The endothelial expression of sLex or sulfo sLex glycans in postcapillary venules was either absent or low in control tissues. The de novo induction of endothelial expression of sLex or sulfo sLex glycans was detected in all inflamed tissues. Furthermore, each organ carried its own modification of sLex or sulfo sLex glycans, ie, zip code. Our results suggest that these zip code glycans may provide means for organ selective leukocyte traffic that could be used in selective leukocyte traffic inhibition.