HEMATOPOIETIC PROGENITOR CELLS OF PLACENTAL AND UMBILICAL CORD BLOOD: IMMUNOPHENOTYPIC ANALYSIS AND DIFFERENTIATION POTENTIAL in vitro

The aim of the work was the comparative studing of the character of differentiation of hematopoietic progenitor cells of the placenta and umbilical cord blood in vivo and their multipotent properties in vitro. The proposed methods were used for mononuclear cells isolation from umbilical cord blood, placental tissue and mature fetal chorion, of flow cytometry and of analysis of the potential for differentiation. We found that majority of hematopoietic progenitor cells both in mature placenta and umbilical cord blood remains uncommitted, however in placental tissue we found more amount of differentiated cells that include myeloid progenitor with a phenotype CD34+CD45lowCD33+SSClow, later myeloid progenitors with a phenotype CD34+CD45lowCD14+SSClow (their content is significantly higher than in cord blood), erythroid progenitors with a phenotype CD34+CD45lowCD235+SSClow (their number significantly above than that in cord blood), B-lymphoid progenitors with a phenotype CD34+CD45lowCD19+SSClow, T-lymphoid progenitors and Natural Killer Cells-progenitors with a phenotype CD34+CD45lowCD7+SSClow, and also T-lymphocytes at the different stages of maturation with a phenotypes CD7+CD45+ and CD7+CD45RA+CD45+ respectively. Placental hematopoietic progenitor cells have similar potential for differentiation in vitro in comparison with cord blood ones. Presence of hematopoietic cells in placental tissue at different stages and lines of differentiation suggests that the placental hematopoiesis last during all term of gestation.