Human mesenchymal stem cells derived from umbilical cord and bone marrow exert immunomodulatory effects in different mechanisms

Figure 2 Immunomodulatory effects of interferon-gamma-stimulated mesenchymal stem cells. Umbilical cord-derived mesenchymal stem cells and bone marrow-derived mesenchymal stem cells were stimulated with 0, 1, 5 or 10 ng/mL of interferon-gamma in culture for 72 h. A and C: Expression of indoleamine 2,3-dioxygenase (A) and cyclooxygenase-2 (C) of interferon-gamma-stimulated mesenchymal stem cells measured by western blotting; B, D and E: Expression of indoleamine 2,3-dioxygenase (B), prostaglandin E2 (D), and interleukin-6 (E) in cultured medium measured by ELISA; F and G: Expression of PD-L1 (F) and PD-L2 (G) after interferon-gamma stimulation analyzed by flow cytometry. Statistical analysis was performed by Student’s t-tests, ^aP < 0.05; ^bP < 0.01; ^cP < 0.0001 vs indicated group. B, D and E: ^aP < 0.05; ^bP < 0.01; ^cP < 0.0001 vs first bar of each group (F and G). BM-MSC: Bone marrow-derived mesenchymal stem cells; IDO: Indoleamine 2,3-dioxygenase; IFN-γ: Interferon-gamma; IL-6: Interleukin 6; iNOS: Inducible nitric oxide synthase; MFI: Mean fluorescence intensity; ND: Not detected; PGE2: Prostaglandin E2; UC-MSC: Umbilical cord-derived mesenchymal stem cells.