Long-Term Propagation of Distinct Hematopoietic Differentiation Programs In Vivo

Abstract

Heterogeneity in the differentiation behavior of hematopoietic stem cells is well documented but poorly understood. To investigate this question at a clonal level, we isolated a subpopulation of adult mouse bone marrow that is highly enriched for multilineage in vivo repopulating cells and transplanted these as single cells, or their short-term clonal progeny generated in vitro, into 352 recipients. Of the mice, 93 showed a donor-derived contribution to the circulating white blood cells for at least 4 months in one of four distinct patterns. Serial transplantation experiments indicated that two of the patterns were associated with extensive self-renewal of the original cell transplanted. However, within 4 days in vitro, the repopulation patterns subsequently obtained in vivo shifted in a clone-specific fashion to those with less myeloid contribution. Thus, primitive hematopoietic cells can maintain distinct repopulation properties upon serial transplantation in vivo, although these properties can also alter rapidly in vitro.

Epigenetic Memory Underlies Cell-Autonomous Heterogeneous Behavior of Hematopoietic Stem Cells

“…Overall, our data are consistent with behavioral features of individual HSC clones being established in development prior to young adulthood and persistently manifest under varying conditions. Lineage bias and proliferative potency has been demonstrated previously (Dykstra et al, 2007;Morita et al, 2010;Muller-Sieburg et al, 2004;Picelli et al, 2013), including at the clonal level (Sun et al, 2014b). The data here indicate that multiple other characteristics including sensitivity to inflammation or radiation are also clone-specific features.…”

“…These include cells that have distinctive behaviors in terms of cell production and lineage bias (Dykstra et al, 2007;Picelli et al, 2013). Hematopoietic stem cells have been demonstrated to exhibit bias toward myeloid, lymphoid, or megakaryocytic lineage upon transplantation of single cells (Dykstra et al, 2007(Dykstra et al, , 2011Morita et al, 2010), on ex vivo barcoding and transplantation of populations (Aiuti et al, 2013;Gerrits et al, 2010;Jordan and Lemischka, 1990;Lemischka, 1993;Lemischka et al, 1986;Lu et al, 2011;Mazurier et al, 2004;Shi et al, 2002;Snodgrass and Keller, 1987), or by retrotransposon tagging of endogenous cells (Sun et al, 2014b). Further, single-cell transplant data have been coupled with single-cell gene expression analysis on different cells to resolve subpopulations with corresponding gene expression and repopulation potential (Wilson et al, 2015).…”

Epigenetic regulation of aging stem cells

“…Aged HSCs also give rise to more cells of myeloid lineage at the expense of lymphoid fates (Sudo et al, 2000;Kim et al, 2003;Rossi et al, 2005;Cho et al, 2008;Guerrettaz et al, 2008). This myeloid bias in aging HSC populations has been explained by alterations in the subcomposition of the HSC pool, which is thought to contain clones with pre-determined differentiation bias (Dykstra et al, 2007;Cho et al, 2008;Beerman et al, 2010a;Morita et al, 2010). The frequency of myeloid-biased HSC clones, distinguished by their high expression of marker SLAMF1/CD150 (Beerman et al, 2010a;Challen et al, 2010;Morita et al, 2010), increases with age, although the mechanism of this expansion is not yet fully understood.…”

A Lentiviral Fluorescent Genetic Barcoding System for Flow Cytometry-Based Multiplex Tracking

“…This strategy revealed a tendency toward higher color code numbers in murine HSPC and myeloid cells in comparison to lymphoid cells and may reflect intrinsic differences in the lifespan and differentiation potential of the parental HSC clones. 23,34,35 Strikingly, using a conservative threshold of 1% color-coded cell content, mice engrafted with ESLAM cells and with CB CD34 + cells displayed on average 3.5 and 4.5 different barcodes, respectively, when assessing color code distribution in four corresponding murine (lin À c-KIT + , CD4 + /CD8 + , CD19 + , and CD11b + ) and human (hCD34 + , hCD3 + , hCD19 + , and hCD33 + ) cell populations. This slightly higher barcode complexity in color-coded human cells may originate from different experimental design strategies, since xenograft studies were initiated with individually generated cell mixes per mouse, while ESLAM transplantations were performed with aliquots of the same parental cell mix ( Figures 5A and 6A).…”