Defining Hematopoietic Stem and Progenitor Cell Turnover by Analysis of Histone 2B-GFP Dilution

• Published in: Nature biotechnology 2008-12, Vol.27 (1), p.84-90
• Main Authors: Foudi, Adlen, Hochedlinger, Konrad, Van Buren, Denille, Schindler, Jeffrey W., Jaenisch, Rudolf, Carey, Vincent, Hock, Hanno
• Format: Article
• Language: English
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/nbt.1517

Hematopoietic stem cells (HSCs) are thought to divide infrequently based on their resistance to cytotoxic injury targeted at rapidly cycling cells 1 , 2 and have been presumed to retain labels such as the nucleotide analogue 5-bromodeoxyuridine (BrdU). However, recently it has been demonstrated that BrdU-retention is neither sensitive nor specific for HSCs 3 . Here we show that transient, transgenic expression of a Histone2B (H2B)-Green Fluorescent Protein (GFP) fusion protein in mice allows superior labeling of HSCs and permits improved analysis of their turnover in combination with other markers. Mathematical modeling of H2B-GFP dilution in HSCs, identified with a highly stringent marker combination (L − K + S + CD48 − CD150 + ) 4 , revealed unexpected heterogeneity in their proliferation rates and suggests that ~ 20% of HSCs turn over at an extremely low rate (≤ 0.8–1.8% per day). Prospective isolation and transplantation of L − K + S + CD48 − CD150 + HSCs with different H2B-GFP levels revealed that higher H2B-GFP label retention correlates with superior long-term repopulation potential.