Work

Notch-dependent T-lineage commitment occurs at extrathymic sites following bone marrow transplantation

Year: 2006

Type: article

Abstract: Early T-lineage progenitors (ETPs) arise after colonization of the thymus by multipotent bone marrow progenitors. ETPs likely serve as physiologic progenitors of T-cell development in adult mice, although alternative T-cell differentiation pathways may exist. While we were investigating mechanisms of T-cell reconstitution after bone marrow transplantation (BMT), we found that efficient donor-derived thymopoiesis occurred before the pool of ETPs had been replenished. Simultaneously, T lineage-restricted progenitors were generated at extrathymic sites, both in the spleen and in peripheral lymph nodes, but not in the bone marrow or liver. The generation of these T lineage-committed cells occurred through a Notch-dependent differentiation process. Multipotent bone marrow progenitors efficiently gave rise to extrathymic T lineage-committed cells, whereas common lymphoid progenitors did not. Our data show plasticity of T-lineage commitment sites in the post-BMT environment and indicate that Notch-driven extrathymic Tlineage commitment from multipotent progenitors may contribute to early T-lineage reconstitution after BMT.

Source: Blood

DOI: 10.1182/blood-2005-08-3454