Leukosialin (CD43) defines hematopoietic progenitors in human embryonic stem cell differentiation cultures

MA Vodyanik, JA Thomson, II Slukvin - Blood, 2006 - ashpublications.org
MA Vodyanik, JA Thomson, II Slukvin
Blood, 2006ashpublications.org
During hematopoietic differentiation of human embryonic stem cells (hESCs), early
hematopoietic progenitors arise along with endothelial cells within the CD34+ population.
Although hESC-derived hematopoietic progenitors have been previously identified by
functional assays, their phenotype has not been defined. Here, using hESC differentiation in
coculture with OP9 stromal cells, we demonstrate that early progenitors committed to
hematopoietic development could be identified by surface expression of leukosialin (CD43) …
Abstract
During hematopoietic differentiation of human embryonic stem cells (hESCs), early hematopoietic progenitors arise along with endothelial cells within the CD34+ population. Although hESC-derived hematopoietic progenitors have been previously identified by functional assays, their phenotype has not been defined. Here, using hESC differentiation in coculture with OP9 stromal cells, we demonstrate that early progenitors committed to hematopoietic development could be identified by surface expression of leukosialin (CD43). CD43 was detected on all types of emerging clonogenic progenitors before expression of CD45, persisted on differentiating hematopoietic cells, and reliably separated the hematopoietic CD34+ population from CD34+CD43CD31+KDR+ endothelial and CD34+CD43CD31KDR mesenchymal cells. Furthermore, we demonstrated that the first-appearing CD34+CD43+CD235a+CD41a+/–CD45 cells represent precommitted erythro-megakaryocytic progenitors. Multipotent lymphohematopoietic progenitors were generated later as CD34+CD43+CD41aCD235aCD45 cells. These cells were negative for lineage-specific markers (Lin), expressed KDR, VE-cadherin, and CD105 endothelial proteins, and expressed GATA-2, GATA-3, RUNX1, C-MYB transcription factors that typify initial stages of definitive hematopoiesis originating from endothelial-like precursors. Acquisition of CD45 expression by CD34+CD43+CD45Lin cells was associated with progressive myeloid commitment and a decrease of B-lymphoid potential. CD34+CD43+CD45+Lin cells were largely devoid of VE-cadherin and KDR expression and had a distinct FLT3highGATA3lowRUNX1lowPU1highMPOhighIL7RAhigh gene expression profile.
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