The human chorion contains definitive hematopoietic stem cells from the fifteenth week of gestation

• DOI: 10.1242/dev.138438
• Publication Date: 2017-03-03T01:25:31Z
• Authors: Marcus O. Muench; Mirhan Kapidzic; Matthew Gormley; Alan G. Gutierrez; Kathryn L. Ponder; Marina E. Fomin; Ashley I. Beyer; Haley Stolp; Zhongxia Qi; Susan J. Fisher; Alicia Bárcena
• Keywords: Homing (biology); Amnion

We examined the contribution of fetal membranes, amnion and chorion, to human embryonic hematopoiesis. A population cells displaying a hematopoietic progenitor phenotype (CD34++ CD45low) origin was present in chorion at all gestational ages, associated with stromal or near blood vessels, but absent amnion. Prior 15 weeks gestation, these lacked vivo engraftment potential. Differences chemokine receptor β1 integrin expression profiles progenitors between first second trimesters suggest that had gestationally regulated responses homing signals and/or adhesion mechanisms influenced their ability colonize stem cell niche. Definitive cells, capable multilineage long-term reconstitution when transplanted immunodeficient mice, were from 15-24 term. The trimester also engrafted secondary recipients serial transplantation experiments. Thus, contains functionally mature mid-gestation.