The immunomodulatory effects of bone marrow-derived mesenchymal stem cells on lymphocyte in spleens of aging rats

Objective: To investigate the effects of bone marrow-derived mesenchymal stem cells (BMSCs) on the proliferation and secretion of IgM, IgG and IL-2 in spleen lymphocytes (L) of aging rats. Methods: BMSCs were isolated by the whole bone marrow adherence method and characterized. A rat model of aging was produced by daily subcutaneous injection of D-galactose into the back of the neck. Rat spleen lymphocyte isolate kit to isolate spleen lymphocytes from aging rats and young rats. In vitro , the co-culture system of BMSCs and aging rats lymphocytes was established, and under the induction of mitogen LPS and ConA, the proliferative activity of lymphocytes in each group was detected by CCK-8 assay, the levels of IgM and IgG in the culture supernatant of each group was detected by ELISA, and the IL-2 radioimmunoassay kits were used to detect the content of IL-2 in the supernatant of each group. Results: (1) The isolated adherent cells showed the characteristics of BMSCs, including spindle-shaped morphology, high expression of CD29, CD44, low expression of CD34 and CD45, and osteogenic/adipogenic ability. (2) Under LPS induction, lymphocyte proliferative activity and secretion of immunoglobulin IgG were reduced in the aging group compared with the young group, and co-culture with BMSCs reversed this trend. (3) Under ConA induction, the IL-2 content of BMSCs co-cultured with aging lymphocytes was higher than that of aging lymphocytes alone ( P < 0.0001); the IL-2 content of CsA co-cultured with aging lymphocytes was lower than that of aging lymphocytes alone ( P < 0.0001). Conclusion: BMSCs have immunomodulatory effects on the spleen lymphocytes of aging rats in vitro .