title: Expression and function of the Eph A receptors and their ligands ephrins A in the rat thymus.
abstract: Thymus development and function are dependent on the definition of different and graded microenvironments that provide the maturing T cell with the different signals that drive its maturation to a functional T lymphocyte. In these processes, cell-cell interactions, cell migration, and positioning are clues for the correct functioning of the organ. The Eph family of receptor tyrosine kinases and their ligands, the ephrins, has been implicated in all these processes by regulating cytoskeleton and adhesion functioning, but a systemic analysis of their presence and possible functional role in thymus has not yet been conducted. In this regard, the current study combines different experimental approaches for analyzing the expression of four members of the Eph A family and their ligands, ephrins A, in the embryonic and adult rat thymus. The patterns of Eph and ephrin expression in the distinct thymic regions were different but overlapping. In general, the studied Eph A were expressed on thymic epithelial cells, whereas ephrins A seem to be more restricted to thymocytes, although Eph A1 and ephrin A1 are expressed on both cell types. Furthermore, the supply of either Eph A-Fc or ephrin A-Fc fusion proteins to fetal thymus organ cultures interferes with T cell development, suggesting an important role for this family of proteins in the cell mechanisms that drive intrathymic T cell development.
authors.affiliation: Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Muñoz
authors.forename: Luis M
authors.initials: LM
authors.lastname: Alonso-C
authors.forename: Rosa
authors.initials: R
authors.lastname: Sacedón
authors.forename: Tessa
authors.initials: T
authors.lastname: Crompton
authors.forename: Angeles
authors.initials: A
authors.lastname: Vicente
authors.forename: Eva
authors.initials: E
authors.lastname: Jiménez
authors.forename: Alberto
authors.initials: A
authors.lastname: Varas
authors.forename: Agustín G
authors.initials: AG
authors.lastname: Zapata
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D036382:Ephrin-A1; D036383:Ephrin-A2; D036384:Ephrin-A3; D036385:Ephrin-A4; D005333:Fetus; D006131:Growth Inhibitors / Q000502:physiology; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000502:physiology; D008024:Ligands; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D009924:Organ Culture Techniques; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis* / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D036382:Ephrin-A1; D036383:Ephrin-A2; D036384:Ephrin-A3; D036385:Ephrin-A4; D006131:Growth Inhibitors; D007141:Immunoglobulin Fc Fragments; D008024:Ligands; D008565:Membrane Proteins; D011506:Proteins; D014157:Transcription Factors; D020794:Receptor Protein-Tyrosine Kinases