Fig. 7. Extracellular vesicles isolated from synovial fluid of patients with juvenile idiopathic arthritis are immunosuppressive.

a, b Flow cytometric analysis of a immune cell subsets and b CD73 and CD39 expression in SF and PB of JIA patients. c CD73 in the cell-free moiety of SF was measured by ELISA. d SF was incubated with eAMP and degradation of eAMP was determined by HPLC. e CD73⁻ CD4con T cells were stimulated with αCD3/αCD28 in the presence of the ADA inhibitor EHNA (10 µM) and incubated with ATP (50 µM), recombinant CD73 (15 ng/mL), EVs (3.1 × 10⁸ particles), and PSB-14685 (10 µM) as indicated. CD25 expression and proliferation were measured after 4 days by flow cytometry. Data were shown for a eight individual donors, as mean of b nine, c fifteen, and d four donors indicated by dots, or for e a representative donor out of three analyzed (mean of technical replicates), marked as a red dot in b–d. A two-tailed Wilcoxon test was used to compare ectonucleotidase expression in PB and SF in b.