Mesenchymal stem/stromal cells (MSCs) are a heterogeneous population of multipotent cells characterized by their ability for self-renewal and differentiation into different cell lineages. Their identification is based on the criteria of the International Society for Cell & Gene Therapy (ISCT), which include plastic adherence, differentiation into osteogenic, chondrogenic and adipogenic lineages, and a characteristic immunophenotype (≥ 95 % positive cells for CD73, CD90 and CD105, and ≤ 2 % positive cells for hematopoietic markers).
MSCs can be isolated from different sources, among which perinatal tissues are becoming increasingly important, because they represent an ethically acceptable and accessible source of cells after birth. In this master’s thesis, we analyzed surface markers of primary cells isolated from the amniotic membrane and placenta, specifically decidua. We analyzed the expression of positive MSCs markers CD73, CD90 and CD105, and the expression of hematopoietic markers CD45, CD235a and CD146. We also analyzed whether there is a difference in the expression of these markers between cells isolated from the amniotic membrane and placenta.
Our results showed that analyzed primary cells do not fulfill the ISCT criteria for MSCs. None of the analyzed samples simultaneously reached ≥ 95 % expression of all three positive markers CD73, CD90 and CD105, together with ≤ 2 % expression of the hematopoietic markers CD45, CD235a and CD146. When comparing cells isolated from the amniotic membrane and placenta, no statistically significant differences were found in the expression of the analyzed markers.
Different biological and technical factors could have affected our results, such as the heterogeneity of MSCs, the method of isolation, cell culture conditions and possible weak binding of the antibodies used for flow cytometry analysis. We concluded that for a more accurate immunophenotypic characterization of primary cells from perinatal tissues, it would be useful to expand the panel of surface markers, optimize the immunophenotyping protocol and perform the analysis on a larger number of samples.
|