The earliest thymic progenitors in adults are restricted to T, NK, and dendritic cell lineage and have a potential to form more diverse TCRbeta chains than fetal progenitors.

The Earliest Thymic Progenitors in Adults Are Restricted to T, NK, and Dendritic Cell Lineage and Have a Potential to Form More Diverse TCR Chains than Fetal Progenitors

Thymic anlage is colonized by progenitors restricted to T, NK, and dendritic cell lineages.

It remains controversial whether the thymus-colonizing progenitors are committed to the T cell lineage. A major problem that has impeded the characterization of thymic immigrants has been that the earliest intrathymic progenitors thus far identified do not necessarily represent the genuine thymic immigrants, because their developmental potential should have been influenced by contact with the t...

Identification of the earliest prethymic T-cell progenitors in murine fetal blood.

During murine fetal development, hemato-poietic progenitors start to colonize the thymic anlage at day 11 of gestation via blood stream. The present study aims at identifying the earliest prethymic progenitors in circulation. Here, we show that the interleukin-7 receptor-positive (IL-7R+) cells in Lin- c-kit+ population are circulating exclusively between days 11 and 14 of fetal age. Clonal ana...

Delineation of intrathymic T, NK, and dendritic cell (DC) progenitors in fetal and adult rats: demonstration of a bipotent T/DC intermediate precursor.

We previously published study results stating that the early rat fetal liver contains a high frequency of T/dendritic cells (DCs), but rarely T/NK bipotent common progenitors. Now, by using xenogenic rat/SCID mouse fetal thymic organ cultures, we extend these observations to the thymus, in which conflicting data have been published in human and mouse. On the one hand, enriched adult intrathymic...

Forced expression of Id2 in fetal thymic T cell progenitors allows some of their progeny to adopt NK cell fate.

The E proteins are indispensable for early T cell development. On the other hand, we previously demonstrated that their inhibitor Id2 is essential for NK lineage commitment from bipotent progenitors generating both T and NK cells (p-T/NK). To shed more light on the role of E proteins and Id2 in the development of early intrathymic progenitors, we performed a clonal analysis: individual fetal th...