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Characterization of E‐selectin‐binding epitopes expressed by skin‐homing T cells
Author(s) -
Richard Priest,
Michael I. Bird,
Rajneesh Malhotra
Publication year - 1998
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1046/j.1365-2567.1998.00551.x
Subject(s) - epitope , homing (biology) , selectin , sialyl lewis x , glycoprotein , e selectin , microbiology and biotechnology , antibody , lectin , receptor , lymphocyte homing receptor , l selectin , chemistry , biology , biochemistry , cell adhesion molecule , cell , cell adhesion , immunology , ecology
The glycoprotein counter‐receptors for E‐selectin borne on skin‐homing T cells are poorly defined. In this study we have used flow cytometry to investigate the surface expression of potential carbohydrate ligands for E‐selectin on HUT78, a skin‐homing cutaneous T‐cell lymphoma. These cells possessed high surface expression of the KM‐93 epitope but not HECA 452 or CSLEX1 epitopes. The KM‐93 antibody also blocked the binding of HUT78 cells to E‐selectin. All these antibodies are reported to recognize sialyl Lewis X (sLe x )‐like molecules. Using an E‐selectin affinity matrix, the main glycoprotein isolated from HUT78 cells was a molecular species of 90 000 MW. Other minor species of molecular weights 40 000, 60 000, 100 000, 120 000 and 200 000 were also identified as potential counter‐receptors for E‐selectin. Four of the purified counter‐receptors (90 000, 100 000, 120 000 and 200 000 MW) stained positive with the KM‐93 antibody. Immunoblot analysis of these purified glycoproteins established the identity of the 90 000 MW glycoprotein as l‐selectin. Furthermore, an anti‐l‐selectin antibody inhibited the binding of HUT78 cells to E‐selectin, probably by steric inhibition of the carbohydrate ligand for E‐selectin that is borne on the C‐type lectin domain of l‐selectin. These results suggest that a carbohydrate epitope on l‐selectin may act as a ligand for E‐selectin on skin‐homing T cells.