title: CD34+ cells in maternal placental blood are mainly fetal in origin and express endothelial markers.
abstract: Fetal CD34+ cells enter the maternal circulation during pregnancy and may persist for decades. These cells are usually depicted as hematopoietic stem/progenitor cells. Our objective was to further determine the phenotype of fetal chimeric CD34+ cells in placental maternal blood from the intervillous space (IVS). Human healthy term placentas were analyzed (n=9). All fetuses were male. CD34+ cells were identified in the IVS and further characterized as fetal or maternal using X and Y chromosome fluorescence in situ hybridization. The phenotype of fetal cells was further analyzed using anti-CD117 (c-kit), anti-CD133, anti-CD31, anti-von Willebrand factor (vWF), anti-vimentin, anti-CD45 and anti-cytokeratin (CK) antibodies. We used preeclamptic placentas of male (n=3) and healthy placentas of female fetuses (n=3) as controls. As expected fetal cells were easily identified in the IVS and significantly increased in cases of preeclampsia. Most CD34+ cells in the IVS were of fetal origin (90%) and were not surrounded by CK staining further showing that they were not in fetal trophoblastic villi. Similarly, about 40% of CD31+ and 6% of vimentin+ cells in the IVS were fetal in origin. No CD117+ or CD133+ fetal cells were found in the IVS of examined placentas. Besides, all the CD34+ cells identified in the IVS were co-labeled with vWF or CD31, suggesting their endothelial origin. These results suggest that most CD34+ cells in maternal placental blood at term are fetal in origin from endothelial and not hematopoietic lineages.
authors.affiliation: UPMC Univ Paris 6, Laboratoire de Physiopathologie du Développement, EA 4053, Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Parant
authors.forename: Gil
authors.initials: G
authors.lastname: Dubernard
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Challier
authors.forename: Michèle
authors.initials: M
authors.lastname: Oster
authors.forename: Serge
authors.initials: S
authors.lastname: Uzan
authors.forename: Sélim
authors.initials: S
authors.lastname: Aractingi
authors.forename: Kiarash
authors.initials: K
authors.lastname: Khosrotehrani
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000097:blood*; D015415:Biomarkers / Q000378:metabolism; D019070:Cell Lineage; D002478:Cells, Cultured; D002678:Chimera / Q000235:genetics / Q000378:metabolism; D046528:Chimerism; D002824:Chorionic Villi / Q000098:blood supply / Q000378:metabolism*; D041321:Chromosomes, Human, X / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000166:cytology* / Q000378:metabolism; D005865:Gestational Age; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008431:Maternal-Fetal Exchange / Q000502:physiology*; D010641:Phenotype; D011225:Pre-Eclampsia / Q000097:blood / Q000473:pathology; D011247:Pregnancy / Q000097:blood*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D055815:Young Adult
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers