TNF-α and IFN-γ promote lymphocyte adhesion to endothelial junctional regions facilitating transendothelial migration.
Inflammatory conditions induce redistribution of junctional adhesion receptors toward the apical regions of endothelial cells promoting lymphocyte TEM. Much of the molecular structures of TEM have been revealed; however, the biophysical mechanisms underlying this process remain to be fully elucidated. Here, we used immunofluorescence microscopy and AFM to study endothelial distribution of adhesion molecules upon lymphocyte activation and transmigration. Our immunofluorescence results revealed redistribution of JAM-A and PECAM-1 but not ICAM-1 or VCAM-1 toward the apical junctional regions of HUVECs following a 6-h stimulation with TNF-α and IFN-γ. Consistently, our SCFS studies revealed that Jurkat cell adhesion to stimulated HUVEC monolayers was significantly greater in junctional regions. Enhanced adhesion was mediated mostly by JAM-A receptors. Further AFM adhesion mapping of the homophilic JAM-A/JAM-A interaction on the surfaces of HUVECs revealed a greater number of JAM-A receptors available for binding along junctional regions after TNF-α and IFN-γ stimulation. Our data reveal for the first time that adhesion "hot spots" of JAM-A receptors are involved in initiating lymphocyte TEM under inflammatory conditions.
1.Florida Atlantic University, 777 Glades Rd., P.O. Box 3091, Boca Raton, FL 33431, USA. ewojciki@fau.edu.
Justyna
J
Jaczewska
Midhat H
MH
Abdulreda
Chi Y
CY
Yau
Martin M
MM
Schmitt
Irene
I
Schubert
Per-Olof
PO
Berggren
Christian
C
Weber
Rory R
RR
Koenen
Vincent T
VT
Moy
Ewa P
EP
Wojcikiewicz
D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007365:Intercellular Junctions / Q000187:drug effects / Q000378:metabolism*; D007371:Interferon-gamma / Q000494:pharmacology*; D019169:Jurkat Cells; D008214:Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018625:Microscopy, Atomic Force; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D013057:Spectrum Analysis; D057705:Transendothelial and Transepithelial Migration / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D015815:Cell Adhesion Molecules; C407243:F11R protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma
atomic force microscopy; immunofluorescence imaging; junctional adhesion molecule-A; single-cell force spectroscopy