title: The impact of negative selection on thymocyte migration in the medulla.
abstract: Developing thymocytes are screened for self-reactivity before they exit the thymus, but how thymocytes scan the medulla for self antigens is unclear. Using two-photon microscopy, we observed that medullary thymocytes migrated rapidly and made frequent, transient contacts with dendritic cells. In the presence of a negative selecting ligand, thymocytes slowed, became confined to areas of approximately 30 microm in diameter and had increased contact with dendritic cells surrounding confinement zones. One third of polyclonal medullary thymocytes also showed confined, slower migration and may correspond to autoreactive thymocytes. Our data suggest that many autoreactive thymocytes do not undergo immediate arrest and death after encountering a negative selecting ligand but instead adopt an altered migration program while remaining in the medullary microenvironment.
authors: Department of Molecular and Cell Biology, University of California, Berkeley, USA.
authors: Marie
authors: M
authors: Le Borgne
authors: Ena
authors: E
authors: Ladi
authors: Ivan
authors: I
authors: Dzhagalov
authors: Paul
authors: P
authors: Herzmark
authors: Ying Fang
authors: YF
authors: Liao
authors: Arup K
authors: AK
authors: Chakraborty
authors: Ellen A
authors: EA
authors: Robey
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D051858:Forkhead Transcription Factors / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
chemical_list: D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D011948:Receptors, Antigen, T-Cell