Microenvironments which support extramedullary hematopoiesis

The organogenesis of spleen is dependent on formation of stromal cell networks which support development and function of hematopoietic cells. In bone marrow, osteoprogenitors are essential in the establishment of niches for hematopoietic stem cells (HSC). However, extramedullary hematopoiesis occurs in spleen and liver in the apparent absence of bone-forming cells. HSC have been localised in spleen in contact with sinusoids, but whether endothelial cells contribute to hematopoiesis has not been evaluated. This project will identify novel stromal components of murine spleen which support hematopoiesis, and investigate their ability to independently form ectopic or artificial tissues.