Heterogeneity of immunomodulatory function of exosomes derived from human umbilical cord mesenchymal stem cells / 军事医学

ABSTRACT

Objective To investigate the heterogeneity of immunomodulatory function of exosomes secreted from human umbilical cord-derived mesenchymal stem cells(hUC-MSC).Methods Five different hUC-MSCs lines were isolated and cultured.Exosomes were isolated from the supernatant.The expression of specific surface markers CD9,CD63,CD81 and CD44 was detected by flow cytometry.The protein concentration of hUC-MSCs exosomes(hUC-MSCs-ex)was evaluated by the BCA assay.Concanavalin A and rhIL-2 stimulated umbilical cord blood mononuclear cells (UBMCs) from healthy donor were co-cultured at different concentrations of hUC-MSCs-ex from different cell lines for 72 h.The growth rate of UBMCs was detected by MTT assay.ELISA was used to test the levels of IFN-γ and TNF-α of the supernatants.The UBMCs co-cultured with hUC-MSCs were co-cultured with K562 cells at the ratio of 5∶1.The cytotoxic activity was calculated by MTT assay.Results hUC-MSCs-ex expressed CD9,CD63,CD81and CD44.Different hUC-MSCs lines had different regulating activities on the proliferation,secretion and killing ability of UBMCs.Conclusion hUC-MSCs-ex has heterogeneity of immunomodulatory function on UBMCs.