The Cytokine Levels of Cord Blood- and Wharton's Jelly-Derived Mesenchymal Stem Cells from Early to Late Passages.

Mesenchymal stem cells (MSCs) are promising for clinical studies owing to their self-renewal, multipotency, trophic, and immunomodulatory properties. This study aimed to investigate the cytokine levels of human umbilical cord blood (CB) and Wharton's Jelly-(WJ) derived MSCs relevant to immune modulation on different passage levels in vitro. Umbilical CB MSCs were isolated using the ficoll-paque gradient method, and WJ-MSCs were isolated by the explant method. After isolation, the MSCs were characterized using flow cytometry. The supernatant cytokine levels (interferon-gamma (IFN-γ), interleukin 4 (IL-4), interleukin 17 (IL-17)) of MSCs at each passage were evaluated using the ELISA assay. MSCs exhibited different cytokine levels with each passage number. In WJ-MSC culture supernatants, IL-17 levels significantly increased at P4 and P5 compared to the first passage (p < 0.005), while the other passages showed a decrease. IFN-γ levels increased at passage P1 and P4 and decreased at other passages (p < 0.005). IL-4 levels significantly increased only at passage P3 (p < 0.005). In CB-MSC culture supernatants, IL-17 and IL-4 cytokines decreased compared to P0, while IFN-γ cytokine increased from P0 (p < 0.005). The changing ratio of cytokine levelsfor both CB-MSCs and WJ-MSCs were similarly maintained from early to late passages. More research is needed to understand the immunomodulatory functions of MSCs.