Human AB serum for generation of mesenchymal stem cells from human chorionic villi: Comparison with other source and other media including platelet lysate

Objectives: We have investigated foetal mesenchymal stem cells (MSCs) obtained from first-trimester chorionic villi (CV) and second-trimester amniotic fluid (AF), comparing them to adult bone marrow-derived MSCs. Materials and methods: We report on cell population growth in human allogeneic serum (HS) and platelet lysate (PL), immunophenotype, cytokine expression profile and immunoregulatory activity, of these foetal MSCs on stimulated peripheral blood mononuclear and lymphocyte subpopulations. Results: Chorionic villi cells grow rapidly in HS, with 20 populations doublings (PDs) after 59days (six passages), and also in animal serum, with 27 PDs after 65days (seven passages). PL allowed for expansion in 60% of the samples tested, although it was lower than in HS. HS supported an average of 40 PDs of expansion in 20% of AF cells after 90days, whereas animal serum supported 28.5 PDs in 66days. CV and AF cells inhibited proliferation of stimulated T lymphocytes, suppressing population growth of both CD4+ and CD8+ T subpopulations and sometimes also, CD19+ cells. Conclusions: Our results indicate that CV would be an optimal source of MSCs with high expansion potential in a HS propagation system and immunoregulatory capacity of T and B lymphocytes. More than 90% of CV samples achieved large-scale expansion in HS, which is encouraging for potential clinical applications of these cells.