title: PlexinD1 glycoprotein controls migration of positively selected thymocytes into the medulla.
abstract: Precise intrathymic cell migration is important for thymocyte maturation and organ architecture. The orchestration of thymocyte trafficking, however, is not well understood at a molecular level. Here, we described highly regulated plexinD1 expression on CD4+CD8+ double positive (DP) thymocytes. PlexinD1 expression was further affected by the engagement of T cell receptor complex. Activation of plexinD1 via the ligand, semaphorin 3E, repressed CCL25 chemokine signaling via its receptor CCR9 in CD69+ thymocytes. In the absence of plexinD1, CD69+ thymocytes remained in the cortex, maturing to form ectopic single positive (SP) thymocyte clusters in Plxnd1-deficient fetal liver cell-transplanted mice. As a consequence, the boundary between DP and SP thymocytes at corticomedullary junctions was disrupted and medullary structures formed under the thymic capsule. These results demonstrate the importance of plexinD1 in directing migration of maturing thymocytes via modulation of biological responses to chemokine gradients.
authors.affiliation: Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
authors.forename: Young I
authors.initials: YI
authors.lastname: Choi
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Duke-Cohan
authors.forename: Wesam B
authors.initials: WB
authors.lastname: Ahmed
authors.forename: Maris A
authors.initials: MA
authors.lastname: Handley
authors.forename: Fanny
authors.initials: F
authors.lastname: Mann
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Epstein
authors.forename: Linda K
authors.initials: LK
authors.lastname: Clayton
authors.forename: Ellis L
authors.initials: EL
authors.lastname: Reinherz
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D002465:Cell Movement / Q000235:genetics / Q000276:immunology*; D003598:Cytoskeletal Proteins; D020869:Gene Expression Profiling; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D054388:Receptors, CCR / Q000378:metabolism; D039961:Semaphorins; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D047908:Intracellular Signaling Peptides and Proteins; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D054388:Receptors, CCR; D039961:Semaphorins; D000099192:CD69 Antigens; C119309:CC chemokine receptor 9; C473552:Plxnd1 protein, mouse; C111150:Sema3e protein, mouse