Aspects of differentiated stem cells for in vivo reconstitution

It was our aim to establish an in vitro differentiation system to prime BALB/c IgM-/-embryonic stem cells (ESCs) for lymphocyte development. We characterised the BALB/c IgM-/- ESC line for markers of pluripotency by fluorescence-activated cell sorting (FACS) and by epifluorescence. Thus we characterised this cell line for the congenic marker expression of CD45.1 and CD45.2 on their surface. As B cell development takes place in the bone marrow the differentiated embryonic stem cells should have the capacity to home to the developmental niches after transfer. Therefore we investigated the homing capacity through Transwell migration assays against C-X-C motif chemokine 12 (CXCL12=SDF1) which represents a powerful attractant for stem cells and progenitor cells and guides the cells to their developmental bone marrow niches.