Persistence of stem cell activity within the murine thymus after transfer of a bone marrow fraction enriched in CFU-S.
Mechanisms involved in prothymocyte migration, differentiation and self-commitment were investigated. We used a murine bone marrow fraction isolated on a discontinuous Ficoll gradient and enriched 10-20 times in CFU-S activity, and studied its fate after intrathymic transfer over a period of 200 days. In order to assess their hemopoietic activity, chimeric thymuses were intravenously transferred to secondary lethally irradiated hosts and both day 8 and day 12 spleen colonies were evaluated. The results show that transfer of a stem cell enriched fraction leads to long-term repopulation of the thymuses and that the input of progenitors is regulated by the size of the intrathymic precursor pool. Furthermore, stem cells can locate within the irradiated thymus and remain in a primitive stage for several months.
Ezine
S
S
INSERM U 25, Hôpital Necker, Paris, France.
Papiernik
M
M
Lepault
F
F
D000818:Animals; D016026:Bone Marrow Transplantation; D002678:Chimera; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013950:Thymus Gland / Q000166:cytology*