Umbilical Cord Mesenchymal Stem Cells γ- Aminobutyric Acid Type 1 Diabetes Peripheral Blood Mononuclear Cells Of Immune Adjustment

Objective:To investigate the immune response reaction impact of different concentrations umbilical cord-derived mesenchymal stem cells (hUCMSCs) as well as in combination with γ-inobutyric acid(GABA) co-culture with peripheral blood mononuclear cells (PBMC) of patients with type1diabetes and to explore its mechanism of action.Methods:Establishing the co-culture system of different concentrations of hUCMSCs as well as in combination with GABA and PBMC of type1diabetes. Taking hUCMSCs as stimulative cells and GABA as the stimulus, PBMC of patients with type1diabetes as the reactive cell.In accordance with the concentration of hUCMSC, it was divided into6groups:The control group:1×105MC cultured alone; the low concentration group:1×104hUCMSC and1×105PBMC co-culture; the medium concentration:1×10’hUCMSC and1×105PBMC co-culture:the high concentration group:1×106hUCMSC and1×105PBMC co-culture; the combination group:1x105hUCMSC in combination with GABA (100μmmol/L) and1×105PBMC; the mannitol group:1×103hUCMSC in combination with mannitol (100μmmol/L) and1×05PBMC.During mixed culture of72h, IL-2, IL-10and AGEs in the supernatant was determined by ELISA kit.and the number and proportion of CD4+、CD8+and CD4+CD25+T lymphocytes were determind by flow cytometry.Results:The flow cytometry rusults show that after the application of hUCMSC,the number of CD4+T and CD4+/CD8+T-proportion were declined to some extent compared with the control group(P<0.05),while the proportion of CD8+T and CD4+CD25+regulatory T cells was significantly increased (P<0.05).They were in a dose-dependent manner. ELISA results show that The level of IL-2and AGEs was significantly declined after the application of hUCMSC(P<0.05) while the level of IL-10was significantly elevated(P<0.05) and they were in a dose-dependent manner. In combination with GABA, compared with the stem cell group of pure medium concentration, the level of IL-2was declined and the level of IL-10was increased (P<0.05),the proportion of CD4+T was reduced and the proportion of CD8+T and CD4+CD25+regulatory T cells was risen(P<0.05).The level of AGEs was declined but not significant.There was no significant change between the medium group and mannitol group. Conclusion:hUCMSCs inhibit the immune responses of PBMC of patients with type1diabetes in vitro as the dose-dependent manner; Inhibitation rate is enhanced when hUCMSCs are combined with GABA.