Effect and mechanism of mesenchymal stem cell derived from different sources on inhibiting follicular helper T cells / 器官移植

ABSTRACT

Objective To investigate the inhibitory effect and underlying mechanism of mesenchymal stem cell (MSC) derived from different sources on follicular helper T cell (Tfh cell). Methods Umbilical cord-derived MSC (UC MSC), bone marrow-derived MSC (BM MSC) and fat-derived MSC (Fat MSC) were co-cultured with peripheral blood mononuclear cell (PBMC) for 48 h. A control group was established. Flow cytometry was adopted to calculate the proportion of Tfh cells among the lymphocytes in four groups. The content of interleukin (IL)-21 in the supernatant was detected by enzyme-linked immune absorbent assay (ELISA) in four groups. BM MSC was co-cultured with PBMC, and supplemented with indoleamine 2,3-dioxygenase (IDO) inhibitor 1-methyl tryptophan (1-MT), IL-10 antibody, human leukocyte antigen (HLA)-G antibody in the 1-MT group, IL-10 inhibition group, HLA-G inhibition group and BM MSC group without addition of other substances. After 48 h culture, flow cytometry was used to detect the percentage of Tfh cells among lymphocytes. Results Flow cytometry demonstrated that compared with the control group, the proportion of Tfh cells in the BM MSC group was significantly decreased (P<0.05). Compared with the BM MSC group, the percentage of Tfh cells in the UC MSC and Fat MSC groups was significantly higher (both P<0.05). ELISA revealed that compared with the control group, the IL-21 content in the BM MSC group was significantly decreased (P<0.05). Compared with the BM MSC group, the IL-21 contents were considerably higher in the UC MSC and Fat MSC groups (both P<0.05). The analysis of underlying mechanism revealed that the proportions of Tfh cells in the 1-MT, IL-10 inhibition and the HLA-G inhibition groups were (1.75±0.07)%, (1.31±0.09)% and (1.50±0.03)%, respectively, which were significantly higher than (1.03±0.43)% in the BM MSC group (all P<0.05). Conclusions BM MSC exerts the highest inhibitory effect upon the differentiation of Tfh cell and IL-21. The mechanism underlying suppressing the differentiation of Tfh cells differentiation is probably correlated to promoting the secretion of IDO.