Isolation and transcriptome analyses of human erythroid progenitors: BFU-E and CFU-E

Abstract

Burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) cells are erythroid progenitors traditionally defined by colony assays.Wedeveloped a flowcytometrybased strategy for isolating human BFU-E and CFU-E cells based on the changes in expression of cell surface markers during in vitro erythroid cell culture. BFU-E and CFU-E are characterized by CD45+ GPA -IL-3R -CD34+CD36-CD71low and CD45+GPA- IL-3R-CD34-CD36+CD71high phenotypes, respectively. Colony assays validated phenotypic assignment giving rise to BFU-E and CFU-E colonies, both at a purity of ∼90%. The BFU-E colony forming ability of CD45+GPA-IL-3R-CD34+CD36-CD71low cells required stem cell factor and erythropoietin, while the CFU-E colony forming ability of CD45+GPA-IL-3R-CD34-CD36+CD71high cells required only erythropoietin. Bioinformatic analysis of the RNA-sequencing data revealed unique transcriptomes at each differentiation stage. Thesortingstrategywas validated inunculturedprimarycells isolated from bone marrow, cord blood, and peripheral blood, indicating that marker expression is not an artifact of in vitro cell culture, but represents an in vivo characteristic of erythroid progenitor populations. The ability to isolate highly pure human BFU-E and CFU-E progenitors will enable detailed cellular and molecular characterization of these distinct progenitor populations and define their contribution to disordered erythropoiesis in inherited and acquired hematologic disease.Our data provides an important resource for future studies of human erythropoiesis.