Growth factor-activated stem cell circuits and stromal signals cooperatively accelerate non-integrated iPSC reprogramming of human myeloid progenitors.
Nonviral conversion of skin or blood cells into clinically useful human induced pluripotent stem cells (hiPSC) occurs in only rare fractions (~0.001%-0.5%) of donor cells transfected with non-integrating reprogramming factors. Pluripotency induction of developmentally immature stem-progenitors is generally more efficient than differentiated somatic cell targets. However, the nature of augmented progenitor reprogramming remains obscure, and its potential has not been fully explored for improving the extremely slow pace of non-integrated reprogramming. Here, we report highly optimized four-factor reprogramming of lineage-committed cord blood (CB) myeloid progenitors with bulk efficiencies of ~50% in purified episome-expressing cells. Lineage-committed CD33(+)CD45(+)CD34(-) myeloid cells and not primitive hematopoietic stem-progenitors were the main targets of a rapid and nearly complete non-integrated reprogramming. The efficient conversion of mature myeloid populations into NANOG(+)TRA-1-81(+) hiPSC was mediated by synergies between hematopoietic growth factor (GF), stromal activation signals, and episomal Yamanaka factor expression. Using a modular bioinformatics approach, we demonstrated that efficient myeloid reprogramming correlated not to increased proliferation or endogenous Core factor expressions, but to poised expression of GF-activated transcriptional circuits that commonly regulate plasticity in both hematopoietic progenitors and embryonic stem cells (ESC). Factor-driven conversion of myeloid progenitors to a high-fidelity pluripotent state was further accelerated by soluble and contact-dependent stromal signals that included an implied and unexpected role for Toll receptor-NFκB signaling. These data provide a paradigm for understanding the augmented reprogramming capacity of somatic progenitors, and reveal that efficient induced pluripotency in other cell types may also require extrinsic activation of a molecular framework that commonly regulates self-renewal and differentiation in both hematopoietic progenitors and ESC.
Institute for Cell Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America.
Tea Soon
TS
Park
Jeffrey S
JS
Huo
Ann
A
Peters
C Conover
CC
Talbot
Karan
K
Verma
Ludovic
L
Zimmerlin
Ian M
IM
Kaplan
Elias T
ET
Zambidis
D000818:Animals; D018952:Antigens, CD34 / Q000096:biosynthesis; D019070:Cell Lineage; D002469:Cell Separation; D065150:Cellular Reprogramming; D018920:Coculture Techniques; D019295:Computational Biology / Q000379:methods; D005347:Fibroblasts / Q000166:cytology; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D051379:Mice; D022423:Myeloid Cells / Q000166:cytology*; D016328:NF-kappa B / Q000378:metabolism; D063268:Sialic Acid Binding Ig-like Lectin 3 / Q000096:biosynthesis; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology*
D018952:Antigens, CD34; D036341:Intercellular Signaling Peptides and Proteins; D016328:NF-kappa B; D063268:Sialic Acid Binding Ig-like Lectin 3; D017493:Leukocyte Common Antigens