Work

Hemogenic Endothelial Cells Can Transition to Hematopoietic Stem Cells through a B-1 Lymphocyte-Biased State during Maturation in the Mouse Embryo

Year: 2019

Type: article

Abstract: Precursors of hematopoietic stem cells (pre-HSCs) have been identified as intermediate precursors during the maturation process from hemogenic endothelial cells to HSCs in the aorta-gonad-mesonephros (AGM) region of the mouse embryo at embryonic day 10.5. Although pre-HSCs acquire an efficient adult-repopulating ability after ex vivo co-culture, their native hematopoietic capacity remains unknown. Here, we employed direct transplantation assays of CD45 − VE-cadherin(VC) + KIT + (V + K + ) cells (containing pre-HSCs) into immunodeficient neonatal mice that permit engraftment of embryonic hematopoietic precursors. We found that freshly isolated V + K + cells exhibited significantly greater B-1 lymphocyte-biased repopulating capacity than multilineage repopulating capacity. Additionally, B cell colony-forming assays demonstrated the predominant B-1 progenitor colony-forming ability of these cells; however, increased B-2 progenitor colony-forming ability emerged after co-culture with Akt-expressing AGM endothelial cells, conditions that support pre-HSC maturation into HSCs. Our studies revealed an unexpected B-1 lymphocyte bias of the V + K + population and acquisition of B-2 potential during commitment to the HSC fate.

Source: Stem Cell Reports

DOI: 10.1016/j.stemcr.2019.05.025