The earliest thymic progenitors for T cells possess myeloid lineage potential

Nature. 2008 Apr 10;452(7188):764-7. doi: 10.1038/nature06840.


There exists controversy over the nature of haematopoietic progenitors of T cells. Most T cells develop in the thymus, but the lineage potential of thymus-colonizing progenitors is unknown. One approach to resolving this question is to determine the lineage potentials of the earliest thymic progenitors (ETPs). Previous work has shown that ETPs possess T and natural killer lymphoid potentials, and rare subsets of ETPs also possess B lymphoid potential, suggesting an origin from lymphoid-restricted progenitor cells. However, whether ETPs also possess myeloid potential is unknown. Here we show that nearly all ETPs in adult mice possess both T and myeloid potential in clonal assays. The existence of progenitors possessing T and myeloid potential within the thymus is incompatible with the current dominant model of haematopoiesis, in which T cells are proposed to arise from lymphoid-. Our results indicate that alternative models for lineage commitment during haematopoiesis must be considered.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Lineage*
  • Cells, Cultured
  • Coculture Techniques
  • Dendritic Cells / cytology
  • Female
  • Granulocytes / cytology
  • Hematopoiesis*
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / metabolism
  • Macrophages / cytology
  • Mice
  • Models, Biological
  • Myeloid Cells / cytology*
  • Myeloid Cells / metabolism
  • Stromal Cells / cytology
  • T-Lymphocytes / cytology*
  • T-Lymphocytes / metabolism
  • Thymus Gland / cytology*