Junctional adhesion molecules and interendothelial junctions.
Similar to epithelia, endothelial cells are linked to each other via intercellular junctional complexes including gap junctions, adherens junctions and tight junctions. While polarized epithelial cells show a high degree of spatial sorting of junctional complexes, endothelia organize their junctions randomly. For this reason the nature of endothelial contacts may be highly adaptable to the need of permeability and leukocyte transmigration. For instance, high endothelial venules (HEVs) in lymphoid organs, where lymphocytes continuously exit the bloodstream, generally show more leaky contacts than brain with its impermeable blood-brain barrier. We recently identified an Ig superfamily molecule named JAM-2 which is specifically expressed in junctions of lymphatic endothelial cells and HEVs. We showed that JAM-2 belongs to the novel CTX molecular family and we now cloned the human equivalent of JAM-2. The presence of JAM-2 at sites of constitutive lymphocyte circulation argues for a role of this molecule in facilitating transmigration. This is supported by the increased transmigration in vitro across endothelial cells overexpressing JAM-2 at intercellular contacts.
Aurrand-Lions
Michel
M
Department of Pathology, Centre Médical Universitaire, Geneva, Switzerland.
Johnson-Leger
Caroline
C
Lamagna
Chrystelle
C
Ozaki
Harunoba
H
Kita
Toru
T
Imhof
Beat A
BA
D000595:Amino Acid Sequence; D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D006801:Humans; D007136:Immunoglobulins / Q000235:genetics / Q000378:metabolism*; D007365:Intercellular Junctions / Q000378:metabolism*; D007962:Leukocytes / Q000378:metabolism; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface; D016415:Sequence Alignment; D014018:Tissue Distribution; D062765:Junctional Adhesion Molecule B
D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; C407243:F11R protein, human; C498686:F11r protein, mouse; C411887:JAM2 protein, human; D062765:Junctional Adhesion Molecule B; C498781:Jam2 protein, mouse