title: Eph/ephrinB signalling is involved in the survival of thymic epithelial cells.
abstract: The signals that determine the survival/death of the thymic epithelial cells (TECs) component during embryonic development of the thymus are largely unknown. In this study, we combine different in vivo and in vitro experimental approaches to define the role played by the tyrosine kinase receptors EphB2 and EphB3 and their ligands, ephrinsB, in the survival of embryonic and newborn (NB) TECs. Our results conclude that EphB2 and EphB3 are involved in the control of TEC survival and that the absence of these molecules causes increased apoptotic TEC proportions that result in decreased numbers of thymic cells and a smaller-sized gland. Furthermore, in vitro studies using either EphB2-Fc or ephrinB1-Fc fusion proteins demonstrate that the blockade of Eph/ephrinB signalling increases TEC apoptosis, whereas its activation rescues TECs from cell death. In these assays, both heterotypic thymocyte-TEC and homotypic TEC-TEC interactions are important for Eph/ephrinB-mediated TEC survival.
authors.affiliation: Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: García-Ceca
authors.forename: David
authors.initials: D
authors.lastname: Alfaro
authors.forename: Sara
authors.initials: S
authors.lastname: Montero-Herradón
authors.forename: Agustín G
authors.initials: AG
authors.lastname: Zapata
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D002450:Cell Communication; D002470:Cell Survival; D036388:Ephrin-B2 / Q000172:deficiency / Q000378:metabolism*; D036389:Ephrin-B3 / Q000172:deficiency / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D005333:Fetus / Q000378:metabolism; D051379:Mice; D036183:Receptor, EphB2 / Q000378:metabolism*; D036223:Receptor, EphB3 / Q000378:metabolism*; D015398:Signal Transduction; D060168:Thymocytes / Q000166:cytology* / Q000378:metabolism
chemical_list: D036388:Ephrin-B2; D036389:Ephrin-B3; D036183:Receptor, EphB2; D036223:Receptor, EphB3