Submitted December 2, 2008
Accepted April 10, 2009
Prospective isolation and molecular characterization of hematopoietic stem cells with durable self-renewal potential
David G. Kent, Michael R. Copley, Claudia Benz, Stefan Wohrer, Brad J. Dykstra, Elaine Ma, John Cheyne, Yongjun Zhao, Michelle B. Bowie, Yun Zhao, Maura Gasparetto, Allen Delaney, Clayton Smith, Marco Marra, and Connie J. Eaves*
Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
University of British Columbia, Vancouver, BC, Canada
Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC, Canada
* Corresponding author; email: ceaves{at}bccrc.ca.
Hematopoietic stem cells (HSCs) are generally defined by their dual properties of pluripotency and extensive self-renewal capacity. However, a lack of experimental clarity as to what constitutes extensive self-renewal capacity coupled with an absence of methods to prospectively isolate longterm repopulating cells with defined self-renewal activities has made it difficult to identify the essential components of the self-renewal machinery and investigate their regulation. We now show that cells capable of repopulating irradiated congenic hosts for 4 months and producing clones of cells that can be serially transplanted are selectively and highly enriched in the CD150+ subset of the EPCR+CD48-CD45+ fraction of mouse fetal liver and adult bone marrow cells. In contrast, cells that repopulate primary hosts for the same period but show more limited self-renewal activity are enriched in the CD150- subset. Comparative transcriptome analyses of these 2 subsets with each other and with HSCs whose self-renewal activity has been rapidly extinguished in vitro revealed 3 new genes (Vwf, Rhob, Pld3) whose elevated expression is a consistent and selective feature of the longterm repopulating cells with durable self-renewal capacity. These findings establish the identity of a phenotypically and molecularly distinct class of pluripotent hematopoietic cells with lifelong self-renewal capacity.
