title: Development of CD4+ macrophages from intrathymic T cell progenitors is induced by thymic epithelial cells.
abstract: It was recently demonstrated that there are CD4(+) macrophages, which exhibit strong phagocytic activity, in the thymus. They are suggested to play an important role for the elimination of apoptotic thymocytes. However, the origin and nature of CD4(+) macrophages in the thymus remain unexplored. In this study, we describe that the most immature intrathymic progenitors (CD25(-)/CD44(+)/FcR(+)) give rise to CD4(+) macrophages by oncostatin M-responsive thymic epithelial cells (ORTEC) in an IL-7-dependent manner. Neither conditioned medium of ORTEC nor a mixture of cytokines induced CD4(+) macrophages, and oncostatin M receptor was not expressed in thymocytes, suggesting that the development of CD4(+) macrophages from the immature thymocytes requires a direct interaction with ORTEC. These results collectively suggest that the development of CD4(+) macrophages from the intrathymic T cell progenitors is induced by thymic epithelial cells.
authors.affiliation: Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Esashi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ito
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ishihara
authors.forename: Toshio
authors.initials: T
authors.lastname: Hirano
authors.forename: Shigeo
authors.initials: S
authors.lastname: Koyasu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyajima
mesh_terms: D000818:Animals; D039481:CD11b Antigen / Q000096:biosynthesis; D015704:CD4 Antigens / Q000096:biosynthesis*; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000502:physiology; D004847:Epithelial Cells / Q000276:immunology*; D005333:Fetus; D015851:Interleukin-7 / Q000502:physiology; D016131:Lymphocyte Subsets / Q000166:cytology / Q000276:immunology; D008264:Macrophages / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D053683:Oncostatin M; D010455:Peptides / Q000494:pharmacology; D013234:Stem Cells / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism
chemical_list: D039481:CD11b Antigen; D015704:CD4 Antigens; D016207:Cytokines; D015851:Interleukin-7; C508352:Osm protein, mouse; D010455:Peptides; D053683:Oncostatin M