Fig. 2

GA-MSC-derived exosomes increase CD73 expression on MDSCs

(A, B) Mouse GA-MSCs-CM and GA-MSCs-CM^− EXO (GA-MSCs-CM depleted of exosomes) were used to stimulate mouse bone marrow cells. The percentage of Gr-1⁺CD11b⁺ MDSCs and the expression of CD73 on MDSCs were measured by flow cytometry. (C, D) PBS, mouse BM-MSCs-derived exosomes or GA-MSCs-derived exosomes were used to stimulate mouse bone marrow cells. The percentage of Gr-1⁺CD11b⁺ MDSCs and the expression of CD73 on MDSCs were measured. (E, F) PBS, mouse BM-MSCs-derived exosomes or GA-MSCs-derived exosomes were intravenously injected into mice. The percentage of Gr-1⁺CD11b⁺ splenic MDSCs and the expression of CD73 on splenic MDSCs were measured. (G, H) Exosomes were isolated from the culture medium of human BM-MSCs and GA-MSCs (induced by U87MG and LN229 cell supernatant) and used to treat PBMCs. The percentage of CD33⁺HLA-DR⁻ MDSCs and the expression of CD73 on MDSCs were measured by flow cytometry. (I) Exosome-induced PBMCs-derived MDSCs were cocultured with CFSE-labeled CD33-depleted PBMCs in the absence or presence of CD73 inhibitor. After 72 h of coculture, CD8⁺ T-cell proliferation was measured using flow cytometry. The data are presented as the mean ± SD; *p < 0.05, **p < 0.01, and ***p < 0.001