Research projects – Group E. Lelièvre

Following their emergence from the aorta hemogenic endothelium, hematopoietic stem cells (HSCs) join and seed a transient hematopoietic organ, the so-called caudal hematopoietic tissue (CHT). The CHT is a complex vascular plexus made of endothelial cells, stromal cells and neuronal extensions that allows HSC expansion and differentiation to give rise to progenitors as well as to mature hematopoietic cells.

HSCs homing in the CHT involves physical interactions with both endothelial and stromal cells triggering the rearrangement of endothelial cells to form “stem cell pockets” that provide the correct environment for HSCs proliferation and a proper balance between stemness maintenance and differentiation.

Our work is currently focusing on the characterization of the mechanisms at work in fish deficient for components of TGF-beta/BMP superfamily that display compromised HSCs engraftment in the CHT. Our current results will provide grounds to a broader project aimed at understanding at both cellular and molecular levels how HSCs, endothelial cells, stromal cells and nerves dialog to establish a fully operative hematopoietic niche.