On the role of Eph signalling in thymus histogenesis; EphB2/B3 and the organizing of the thymic epithelial network.
In the current study, we extend our own previous results on the thymocyte phenotype of EphB2 and/or EphB3 deficient mice by analyzing the phenotype and the histological organization of their thymic epithelial stroma. All studied adult EphB-deficient thymi showed profound alterations with respect to the wild-type (WT) ones. Each mutant exhibited a specific phenotype, but also showed common features including occurrence of K5+K8+MTS10+ immature medullary epithelial cells, numerous K5-K8-MTS20+ cells and K5+K8+ cells in the thymic cortex and cortical and medullary K5-K8- areas devoid of epithelial cell markers. In addition, comparative analysis of WT and EphB-deficient embryonic and newborn thymi demonstrated that the observed adult phenotype was a consequence of the gradual accumulation of early phenotypic and morphological defects, becoming more severe at the end of embryonic life and in newborn animals. Together, these results confirm a role for EphB2 and EphB3 in thymus morphogenesis. The obtained data are discussed from the point of view of the recognized role played by these two Ephs in the homeostasis of other epithelia and their possible relationships with molecules known to be involved in thymic epithelial cell development.
García-Ceca
Javier
J
Department of Cell Biology, Complutense University, Madrid, Spain.
Jiménez
Eva
E
Alfaro
David
D
Cejalvo
Teresa
T
Chumley
Michael J
MJ
Henkemeyer
Mark
M
Muñoz
Juan-José
JJ
Zapata
Agustín G
AG
D000818:Animals; D000831:Animals, Newborn; D004848:Epithelium / Q000002:abnormalities / Q000196:embryology / Q000254:growth & development / Q000502:physiology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D053569:Keratin-15; D053555:Keratin-5 / Q000378:metabolism; D053533:Keratin-8 / Q000378:metabolism; D007797:Laminin / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009024:Morphogenesis / Q000235:genetics / Q000502:physiology; D010641:Phenotype; D011247:Pregnancy; D036183:Receptor, EphB2 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D036223:Receptor, EphB3 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction; D013950:Thymus Gland / Q000002:abnormalities / Q000196:embryology* / Q000254:growth & development* / Q000502:physiology
D000949:Histocompatibility Antigens Class II; D053569:Keratin-15; D053555:Keratin-5; D053533:Keratin-8; C492053:Krt15 protein, mouse; C486595:Krt8 protein, mouse; D007797:Laminin; D036183:Receptor, EphB2; D036223:Receptor, EphB3