Nepmucin/CLM-9, an Ig domain-containing sialomucin in vascular endothelial cells, promotes lymphocyte transendothelial migration in vitro.
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.
Jin
Soojung
S
Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
Umemoto
Eiji
E
Tanaka
Toshiyuki
T
Shimomura
Yoshimitsu
Y
Tohya
Kazuo
K
Kunizawa
Keiji
K
Yang
Bo-Gie
BG
Jang
Myoung Ho
MH
Hirata
Takako
T
Miyasaka
Masayuki
M
D000818:Animals; D002448:Cell Adhesion / Q000276:immunology; D002465:Cell Movement; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology*; D007136:Immunoglobulins / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000276:immunology; D017434:Protein Structure, Tertiary; D052116:Sialomucins / Q000235:genetics / Q000276:immunology*; D022161:Transport Vesicles / Q000276:immunology
D007136:Immunoglobulins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D052116:Sialomucins; C512481:nepmucin, mouse