Primitive lymphoid progenitors in bone marrow with T lineage reconstituting potential

Academic Article


  • Multiple subsets of the bone marrow contain T cell precursors, but it remains unclear which is most likely to replenish the adult thymus. Therefore, RAG-1+ early lymphoid progenitors (RAG-1+ ELP), and CD62L/L-selectin+ progenitors (LSP), as well as common lymphoid progenitors from C57BL6-Thy1.1-RAG-1/GFP mouse bone marrow were directly compared in transplantation assays. The two c-Kithigh populations vigorously regenerated the thymus and were superior to common lymphoid progenitors in magnitude and frequency of thymic reconstitution. Regeneration was much faster than the 22 days described for transplanted stem cells, and RAG-1+ ELP produced small numbers of lymphocytes within 13 days. As previously reported, LSP were biased to a T cell fate, but this was not the case for RAG-1+ ELP. Although RAG-1+ ELP and LSP had reduced myeloid potential, they were both effective progenitors for T lymphocytes and NK cells. The LSP subset overlapped with and included most RAG-1+ ELP and many RAG-1-TdT+ ELP. LSP and RAG-1+ ELP were both present in the peripheral circulation, but RAG-1+ ELP had no exact counterpart among immature thymocytes. The most primitive of thymocytes were similar to Lin-c-KithighL-selectin +TdT+RAG-1- progenitors present in the marrow, suggesting that this population is normally important for sustaining the adult thymus. Copyright © 2006 by The American Association of Immunologists, Inc.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Perry SS; Welner RS; Kouro T; Kincade PW; Sun XH
  • Start Page

  • 2880
  • End Page

  • 2887
  • Volume

  • 177
  • Issue

  • 5