Immunomodulation mechanisms of MSCs. MSCs modulate the immune responses of the target immune cells, using cell-cell interactions and the secretion of soluble molecules

Immunoregulatory mediatorsInteractionsTarget immune cellsResultRefs
Fas/Fas ligandCell-cell contactMacrophages, mDCs, T and B cellsApoptosis[34]
TNF-α/TNF-RCell-cell contactMacrophages, mDCs, T and B cellsApoptosis[38]
PD-L1/PD-1Cell-cell contactT and B cellsInhibition of cellular proliferation[66]
HLA-G/LIRB2 (ILT4/CD85d) and KIR2DL4 (CD158d)Cell-cell contactmDCs, NK cells and T cellsInhibition of cellular proliferation[32, 75]
PGE2Soluble factorsMacrophages, mDCs, T and B cellsM2 macrophages switching
Inhibition of DCs maturation, T and B cell inactivation
[57]
IDOSoluble factorsmDCs NK cells, T and B cellsG0/G1 cell cycle arrest[34, 76]
NOSoluble factorsMacrophages, T and B cellsInhibition of cellular proliferation[34, 76]
GalectinsSoluble factorsT and B cellsInhibition of T and B cell proliferation[76, 77]
Soluble HLA-G isoforms (HLA-G5-G7)Soluble factorsmDCs, NK cells and T cellsInhibition of cellular proliferation[32, 75]
miR-21-5p, miR-142-3p, miR-223-3p, and miR-126-3pSoluble factorsmDCsInhibition of DC maturation[21, 4650]
miR-145, miR-146 and miR-155Soluble factorsMacrophages, T and B cellsInactivation of M1 macrophages; switching from Th1 to Th2 responses[21, 4650]

Note. Adapted with permission from “Mesenchymal stromal cells as potential immunomodulatory players in severe acute respiratory distress syndrome induced by SARS-CoV-2 infection” by Mallis P, Michalopoulos E, Chatzistamatiou T, Stavropoulos-Giokas C. World J Stem Cells. 2020;12:731–51 (https://doi.org/10.4252/wjsc.v12.i8.731). CC BY.