Immunomodulatory effect of Wharton's jelly-derived mesenchymal stem cells from human umbilical cord on human peripheral blood T lymphocytes

BACKGROUND: Bone marrow mesenchymal stem cells have low immunogenicity and immunomodulatory effect, but there are seldom reports concerning the immunomodulatory effect of Wharton's jelly-derived mesenchymal stem cells of human umbilical cord and its mechanims. OBJECTIVE: To investigate the immunomodulatory effects and mechanisms of Wharton's jelly-derived mesenchymal stem cells of human umbilical cord on varient peripheral blood T lymphocytes. METHODS: Mesenchymal stem cells were isolateded from Wharton's jelly of human umbilical cord by tissue culture. T lymphocytes from human peripheral blood were stimulated by phytohemagglutinin and co-cultured with umbilical cord Wharton's jelly-derived mesenchymal stem cells and umbilical cord Wharton's jelly-derived mesenchymal stem cells supernatant respectively to measure A value following 72 hours of coculture using multifunctional microplate reader. Expression of cytokines including transforming growth factor-beta 1 (TGF-β1) and interferon-γ (IFN-γ) was evaluated by enzyme-labeled immunosorbent assay. RESULTS AND CONCLUSION: Wharton's jelly-derived mesenchymal stem cells could inhibite the proliferation of T lymphocytes induced by phytohemagglutinin. The proliferation inhibition rate was 56% (P < 0.01). Wharton's jelly-derived mesenchymal stem cells supernatant also had inhibitory effects on proliferation of T lymphocytes induced by phytohemagglutinin, in a dose-dependent fashion. The proliferation inhibition rates were 8.3% and 27% respectively in the 50% Wharton's jelly-derived mesenchymal stem cells supernatant and 100% Wharton's jelly-derived mesenchymal stem cells supernatant groups (P < 0.05). Wharton's jelly-derived mesenchymal stem cells significantly decreased γ-interferon secrted from T-lymphocytes (P < 0.05). The secretion of TGF-β1 was lower in the coculture of Wharton's jelly-derived mesenchymal stem cells and T lymphocytes group than Wharton's jelly-derived mesenchymal stem cells alone group (P < 0.05). These indicated that Wharton's jelly-derived mesenchymal stem cells and Wharton's jelly-derived mesenchymal stem cells supernatant have inhibitory effects on proliferation of T lymphocytes induced by phytohemagglutinin. The mechanims may be associated with cell contant and inhibition of γ-interferon secrted from T-lymphocytes.