Fig. 1

The role and mechanism of immunological tolerance of MSC-EVs on immune cells. The EVs derived from MSC play immunological tolerant role on the innate and adaptive immune responses including extensive immune cells. MSC-EVs could suppress the activation and proliferation of T cell and reduce production of inflammatory cytokines, while improve the Treg function and anti-inflammatory cytokines generation. Similarly, MSC-EVs play the suppressive role on the proliferation, differentiation, and immunoglobulin secretion of B cell. Considering the innate immune cells, MCS-EVs induce IL-10-expressing regulatory phenotype of DCs and inhibit the co-stimulatory molecules of monocytes. The macrophage would adopt anti-inflammatory M2 phenotype after MSC-EVs stimulation