Landscape of Hematopoiesis Described in Induced Pluripotent Stem Cells and Human Bone Marrow

Granulopoietic differentiation of myeloid progenitor cells derived from control iPSCs was performed in a two-step liquid culture. At the end of culture, stages of differentiation were identified by morphological analysis and submitted for RNA-sequencing analysis in order to provide insight into the genomic landscape of myeloid lineage hematopoiesis as modeled by the in vitro induced differentiation of iPSCs as compared to in vivo bone marrow-derived promyelocytes. Peripheral blood from healthy controls was obtained and iPSC were generated from peripheral blood mononuclear cells. Hematopoietic progenitors generated from control iPSCs when cultured in myeloid expansion medium containing 50ng/mL SCF, 10ng/mL IL-3 and 10ng/mL GM-CSF for 5 days at which point cells were stained for CD45-Pacific blue, CD34-PECy7, CD33-AP, CD11b-APC-Cy7, CD15-FITC. 7-AAD was used to eliminate the dead cells. The promyelocytic population (CD45+CD34-CD33+CD11b-CD15+/lo) was sorted and the RNA from control iPSC promyelocytes was isolated using QIAGEN RNAeasy mini kit. The RNA samples were processed for RNA-seq analyses using RNA-seq protocol from NuGEN and Illumina. The amplified products were sequenced to analyze the gene expression profile of each replicate sample. A total of 20 samples were used in this analysis to characterize and compare iPSC in vitro differentiated myeloid cells with those isolated from human bone marrow.