Description
One of the long-standing goals in the field has been to establish a culture system that would allow maintenance of HSC properties ex vivo. In the absence of such system, the ability to model human hematopoiesis in vitro has been limited, and there has been little progress in the expansion of human HSCs for clinical application. To that end, we defined a mesenchymal stem cell co-culture system based on a monoclonal OP9 stromal cell line (OP9M2), for expansion of clonally multipotent human HSPCs that were protected from apoptosis and immediate differentiation, and retained the HSPC phenotype. To identify the supportive mechanisms, we performed a genome-wide gene expression analysis of OP9M2 stromal cells and compared the expression to a non-supportive stomal line (BFC012). This co-culture system provides a new, well-defined platform for studying mechanisms involved in HSC-niche interactions and protection of critical HSC properties ex vivo.