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

Figure 4 T cell inhibition by mesenchymal stem cells. T cell proliferation was inhibited by either umbilical cord-derived mesenchymal stem cells (MSCs) or bone marrow-derived MSCs in coculture. A: Human peripheral blood mononuclear cells (1 × 10⁵/well) from heathy adult donors were stimulated with phytohemagglutinin (5 μg/mL) with or without MSCs (5 × 10³, 1 × 10⁴, 5 × 10⁴, 1 × 10⁵) for 72 h. In the final 18 h, ³H-thymidine was added to the cultures, ^aP < 0.05; ^bP < 0.01; ^cP <0.0001 vs control of each group, ^eP < 0.01; ^fP < 0.0001 vs control; and B: Human peripheral blood mononuclear cells were treated with L-NAME (iNOS inhibitor), indomethacin (cyclooxygenase-2 inhibitor), anti-IL-10, anti-transforming growth factor-β, hemin (heme oxygenase inducer), alloxazine (selective A_2B adenosine receptor antagonist), or adenosine 5'-(α,β-methylene)diphosphate (CD73 inhibitor) with or without MSCs for 72 h. In the final 18 h, ³H-thymidine was added to the cultures. Statistical analysis was performed by Student’s t-tests ^aP < 0.05; ^bP < 0.01; ^cP < 0.0001 vs control. Anti-IL-10: Anti-interleukin 10 antibody; Anti-TGF-β: Anti-transforming growth factor β antibody; APCP: Adenosine 5'-(α,β-methylene)diphosphate; BM-MSC: Bone marrow-derived mesenchymal stem cells; cpm: Count per minute; L-NAME: N-nitro-L-arginine methyl ester; UC-MSC: Umbilical cord-derived mesenchymal stem cells.