Nepmucin/CLM-9, an Ig domain-containing sialomucin in vascular endothelial cells, promotes lymphocyte transendothelial migration in vitro

• Published in: FEBS letters Vol. 582; no. 20; pp. 3018 - 3024
• Main Authors: Jin, Soojung, Umemoto, Eiji, Tanaka, Toshiyuki, Shimomura, Yoshimitsu, Tohya, Kazuo, Kunizawa, Keiji, Yang, Bo-Gie, Jang, Myoung Ho, Hirata, Takako, Miyasaka, Masayuki
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 03.09.2008
• Subjects: Animals; Cell Adhesion - immunology; Cell Movement; Endothelial cell; Endothelium, Vascular - cytology; Endothelium, Vascular - immunology; HEVs; high endothelial venules; Homophilic adhesion; Immunoglobulins - immunology; lateral border recycling compartment; LBRC; LNs; lymph nodes; Lymphocytes - immunology; MBEC4; Mice; Mice, Inbred C57BL; mouse brain endothelial cell 4; Peyer's patches; Platelet Endothelial Cell Adhesion Molecule-1 - immunology; PPs; Protein Structure, Tertiary; Sialomucins - genetics; Sialomucins - immunology; TEM; Transendothelial migration; Transport Vesicles - immunology; LNs; Homophilic adhesion; PPs; Endothelial cell; LBRC; HEVs; Transendothelial migration; MBEC4; TEM; EC
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2008.07.041

Nepmucin/CLM-9 is an Ig domain-containing sialomucin expressed in vascular endothelial cells. Here we show that, like CD31, nepmucin was localized to interendothelial contacts and to vesicle-like structures along the cell border and underwent intracellular recycling. Functional analyses showed that nepmucin mediated homotypic and heterotypic cell adhesion via its Ig domain. Nepmucin-expressing endothelial cells showed enhanced lymphocyte transendothelial migration (TEM), which was abrogated by anti-nepmucin mAbs that block either homophilic or heterophilic binding. Notably, the mAbs that inhibited homophilic binding blocked TEM without affecting lymphocyte adhesion. These results suggest that endothelial nepmucin promotes lymphocyte TEM using multiple adhesion pathways.