title: Expression of the Receptor Tyrosine Kinase EphB2 on Dendritic Cells Is Modulated by Toll-Like Receptor Ligation but Is Not Required for T Cell Activation.
abstract: The Eph receptor tyrosine kinases interact with their ephrin ligands on adjacent cells to facilitate contact-dependent cell communication. Ephrin B ligands are expressed on T cells and have been suggested to act as co-stimulatory molecules during T cell activation. There are no detailed reports of the expression and modulation of EphB receptors on dendritic cells, the main antigen presenting cells that interact with T cells. Here we show that mouse splenic dendritic cells (DC) and bone-marrow derived DCs (BMDC) express EphB2, a member of the EphB family. EphB2 expression is modulated by ligation of TLR4 and TLR9 and also by interaction with ephrin B ligands. Co-localization of EphB2 with MHC-II is also consistent with a potential role in T cell activation. However, BMDCs derived from EphB2 deficient mice were able to present antigen in the context of MHC-II and produce T cell activating cytokines to the same extent as intact DCs. Collectively our data suggest that EphB2 may contribute to DC responses, but that EphB2 is not required for T cell activation. This result may have arisen because DCs express other members of the EphB receptor family, EphB3, EphB4 and EphB6, all of which can interact with ephrin B ligands, or because EphB2 may be playing a role in another aspect of DC biology such as migration.
authors.affiliation: Division of Infectious Diseases, Department of Pediatric, Emory University School of Medicine, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Patrice N
authors.initials: PN
authors.lastname: Mimche
authors.affiliation: Division of Infectious Diseases, Department of Pediatric, Emory University School of Medicine, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Brady
authors.affiliation: Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom.
authors.forename: Shirley
authors.initials: S
authors.lastname: Keeton
authors.affiliation: Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom.
authors.forename: David S J
authors.initials: DS
authors.lastname: Fenne
authors.affiliation: Division of Infectious Diseases, Department of Pediatric, Emory University School of Medicine, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Thayer P
authors.initials: TP
authors.lastname: King
authors.affiliation: Division of Infectious Diseases, Department of Pediatric, Emory University School of Medicine, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Kendra M
authors.initials: KM
authors.lastname: Quicke
authors.affiliation: Division of Infectious Diseases, Department of Pediatric, Emory University School of Medicine, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Hudson
authors.affiliation: Division of Infectious Diseases, Department of Pediatric, Emory University School of Medicine, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Tracey J
authors.initials: TJ
authors.lastname: Lamb
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008024:Ligands; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D011485:Protein Binding; D036183:Receptor, EphB2 / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D051193:Toll-Like Receptors / Q000378:metabolism*
chemical_list: D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D018836:Inflammation Mediators; D008024:Ligands; D051193:Toll-Like Receptors; D036183:Receptor, EphB2