An impaired transendothelial migration potential of chronic lymphocytic leukemia (CLL) cells can be linked to ephrin-A4 expression.
Chronic lymphocytic leukemia (CLL) cell migration into lymphoid tissues is an important aspect of the pathobiology of this disease. Here, we investigated the role of ephrin-A4 (EFNA4) in the transendothelial migration (TEM) capacity of CLL and normal B cells through interacting with endothelial EphA2 (erythropoietin-producing hepatocellular carcinoma). CLL cells showed a remarkable impairment in the adhesion to and transmigration through human umbilical vein endothelial cell (HUVEC) monolayers, correlating with their higher EFNA4 expression. In vitro, TEM was mediated by EFNA4 binding to endothelial EphA2 receptor, which is highly expressed in tumor necrosis factor-alpha-activated HUVECs as well as in the CD31(+) endothelial cells of human lymph nodes. The pretreatment of CLL cells with EphA2 homodimers further impaired their adhesion to and transmigration through HUVEC monolayers, whereas pretreatment of HUVECs with EFNA4 homodimers improved those phenomena in both CLL and normal B cells, suggesting that EFNA4 signaling negatively contributed to TEM. In fact, EFNA4 signaling into CLL cells significantly reduced their adhesion to intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and several extracellular matrix molecules and impaired CCL-19-mediated TEM and chemotaxis. Our results suggest that EFNA4-EphA2 interactions are involved in CLL cell trafficking between blood and the tissues and therefore may become a therapeutic target in the future.
Trinidad
Eva M
EM
Microscopy and Cytometry Research Centre, Complutense University of Madrid, 28040 Madrid, Spain.
Ballesteros
Mónica
M
Zuloaga
Jaime
J
Zapata
Agustín
A
Alonso-Colmenar
Luis M
LM
D002448:Cell Adhesion / Q000502:physiology; D054415:Chemokine CCL19 / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D004727:Endothelium / Q000378:metabolism*; D036385:Ephrin-A4 / Q000096:biosynthesis*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism*; D018613:Microscopy, Confocal; D036104:Receptor, EphA2 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
D054415:Chemokine CCL19; D036385:Ephrin-A4; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D036104:Receptor, EphA2