FIGURE 5.

Leukaemia‐derived sEVs transfer miR‐19a‐3p to inhibit SLC6A8 expression in CD8+ T cells. (a and b) Leukemic cells transfected with Cy3‐tagged miR‐19a‐3p (Cy3‐miR‐19a‐3p) were co‐cultured with CD8+ T cells for 48 h, with or without GW4869. Fluorescence microscopy was used to detect the related red fluorescent signals in CD8+ T cells. (c) The interference efficiency of miR‐19a‐3p in OCI/AML3 cells and OCI/AML3‐sEVs was detected by qRT‐PCR. U6 expression was detected as an internal control. (d–i) CD8+ T cells incubated with OCI/AML3‐sEVs, with or without miR‐19a‐3p KD. OCI/AML3‐sEVs^NC, OCI/AML3 cells transfected with negative control vector; OCI/AML3‐sEVs^{miR‐19a KD}, OCI/AML3 cells transfected with shRNA targeting miR‐19a‐3p. (d) SLC6A8 expression was analyzed by western blotting. (e) CD8+ T cell proliferation was evaluated by FCM. (f and g) IL‐2 (f) and IFN‐γ (g) levels in supernatants from cell cultures were analyzed using ELISA kits. (h and i) CD25 (h) and Granzyme B (i) expression by CD8+ T cells were determined by FCM