Annexin A8 controls leukocyte recruitment to activated endothelial cells via cell surface delivery of CD63.
To enable leukocyte adhesion to activated endothelium, the leukocyte receptor P-selectin is released from Weibel-Palade bodies (WPB) to the endothelial cell surface where it is stabilized by CD63. Here we report that loss of annexin A8 (anxA8) in human umbilical vein endothelial cells (HUVEC) strongly decreases cell surface presentation of CD63 and P-selectin, with a concomitant reduction in leukocyte rolling and adhesion. We confirm the compromised leukocyte adhesiveness in inflammatory-activated endothelial venules of anxA8-deficient mice. We find that WPB of anxA8-deficient HUVEC contain less CD63, and that this is caused by improper transport of CD63 from late multivesicular endosomes to WPB, with CD63 being retained in intraluminal vesicles. Consequently, reduced CD63 cell surface levels are seen following WPB exocytosis, resulting in enhanced P-selectin re-internalization. Our data support a model in which anxA8 affects leukocyte recruitment to activated endothelial cells by supplying WPB with sufficient amounts of the P-selectin regulator CD63.
1] Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, von-Esmarch Strasse 56, 48149 Münster, Germany [2].
Michaela
M
Poeter
1] Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, von-Esmarch Strasse 56, 48149 Münster, Germany [2].
Ines
I
Brandherm
1] Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany [2] Department of Vascular Cell Biology, Max-Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany.
Jan
J
Rossaint
Institute of Physiology II, University of Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany.
Gonzalo
G
Rosso
Institute of Physiology II, University of Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany.
Victor
V
Shahin
Institute of Experimental Pathology, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, von-Esmarch Strasse 56, 48149 Münster, Germany.
Boris V
BV
Skryabin
1] Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany [2] Department of Vascular Cell Biology, Max-Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany.
Alexander
A
Zarbock
Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, von-Esmarch Strasse 56, 48149 Münster, Germany.
Volker
V
Gerke
Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, von-Esmarch Strasse 56, 48149 Münster, Germany.
Ursula
U
Rescher
D000704:Analysis of Variance; D000818:Animals; D017302:Annexins / Q000378:metabolism*; D000911:Antibodies, Monoclonal; D015139:Blotting, Southern; D015153:Blotting, Western; D002448:Cell Adhesion / Q000276:immunology*; D017931:DNA Primers / Q000235:genetics; D042783:Endothelial Cells / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007962:Leukocytes / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D018625:Microscopy, Atomic Force; D018448:Models, Immunological; D019007:P-Selectin / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D060149:Tetraspanin 30 / Q000378:metabolism*; D020302:Weibel-Palade Bodies / Q000378:metabolism*
D017302:Annexins; D000911:Antibodies, Monoclonal; C554586:CD63 protein, human; D017931:DNA Primers; D019007:P-Selectin; D034741:RNA, Small Interfering; D060149:Tetraspanin 30