The thymus exports long-lived fully committed T cell precursors that can colonize primary lymphoid organs.
Thymic export of cells is believed to be restricted to mature T cells. Here we show that the thymus also exports fully committed T cell precursors that colonize primary lymphoid organs. These precursor cells exited the thymus before T cell receptor rearrangements and colonized lymphoid organs such as the thymus and the gut. Migration of the thymic T cell-committed precursors led to permanent colonization of the gut precursor compartment, improved the capacity of gut precursors to further differentiate into T cells and was sufficient for the generation of 'euthymic like' CD8alphaalpha(+) intraepithelial lymphocytes. These data demonstrate a new function for the thymus in peripheral seeding with T cell precursors that become long lived after thymus export.
Lambolez
Florence
F
Institut National de la Santé et de la Recherche Médicale U591, Necker Institute, Medical Faculty René Descartes, Paris, France.
Arcangeli
Marie-Laure
ML
Joret
Anne-Marie
AM
Pasqualetto
Valérie
V
Cordier
Corinne
C
Di Santo
James P
JP
Rocha
Benedita
B
Ezine
Sophie
S
D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D008221:Lymphoid Tissue / Q000166:cytology*; D051379:Mice; D018613:Microscopy, Confocal; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology