Abstract
Hematopoietic stem cell (HSC) surface markers improve the understanding of cell identity and function. Here, we report that human HSCs can be distinguished by their expression of the CEA Cell Adhesion Molecule 5 (CEACAM5, CD66e), which serves as a marker and a regulator of HSC function. CD66e+ cells exhibited a 5.5-fold enrichment for functional long term HSCs compared to CD66e- cells. CD66e+CD34+CD90+CD45RA- cells displayed robust multi-lineage repopulation and serial reconstitution ability in immunodeficient mice compared to CD66e-CD34+CD90+CD45RA-cells. CD66e expression also identified almost all repopulating HSCs within the CD34+CD90+CD45RA- population. Together, these results indicated that CEACAM5 is a marker that enriches functional human hematopoietic stem cells capable of long-term multi-lineage engraftment.