A comprehensive single cell transcriptional landscape of human hematopoietic progenitors

Hematopoietic Stem/Progenitor cells (HSPCs) are endowed with the role of maintaining a diverse pool of blood cells throughout the human life. Despite recent efforts, the nature of the early cell fate decisions remains contentious. Using single-cell RNA-Seq, we show that existing approaches to stratify bone marrow CD34+ cells reveal a hierarchically-structured transcriptional landscape of hematopoietic differentiation. Still, this landscape misses important early fate decisions. We here provide a broader transcriptional profiling of bone marrow lineage negative hematopoietic progenitors that recovers a key missing branchpoint into basophils and expands our understanding of the underlying structure of early adult human haematopoiesis. We also show that this map has strong similarities in topology and gene expression to that found in mouse. Finally, we identify the sialomucin CD164, as a reliable marker for the earliest branches of HSPCs specification and we showed how its use can foster the design of alternative transplantation cell products. Overall design: Single-cell mRNA sequencing of freshly isolated hematopoietic progenitors from human bone marrow. Sample HSC (Donor A) represents 1282 single cells. Sample MPP (Donor A) represents 215 single cells. Sample MLP (Donor A) represents 123 single cells. Sample PreB/NK (Donor A) represents 592 single cells. Sample MEP (Donor A) represents 1211 single cells. Sample CMP (Donor A) represents 1576 single cells. Sample GMP (Donor A) represents 1012 single cells. Sample Lin-CD34+CD164+ (Donor B) represents 6343 single cells. Sample Lin-CD34-CD164high (Donor B) represents 4434 single cells. Sample Lin-CD34lowCD164high (Donor B) represents 4266 single cells. Sample Lin-CD34-CD164low (Donor B) represents 358 single cells.