Figure 4.

sEV-CC16 inhibits LPS-induced inflammation in macrophages

(A and B) Mice (n = 5 per group) received 1 μg of LPS (in 50 μL of PBS) via i.t. After 3 h, mice were given 7.5 × 10¹⁰ (in 50 μL of PBS) PKH26-labeled sEV-Con or PKH26-labeled EV-CC16 via the i.t. route. Mice were sacrificed 24 h after sEV treatment. Immunofluorescence staining was performed in lung sections (A) and BAL cells (B) using an antibody against CD68 (a macrophage marker) to track the uptake of sEV-Con or sEV-CC16. Scale bar, 100 μm. (C) EV-Con or EV-CC16 labeled with PKH67 was added to THP-1. After 24 h, cells were washed and the internalization of labeled sEV-Con or sEV-CC16 was detected using a fluorescence microscope. Scale bar, 100 μm. (D–G) Differentiated THP-1 cells were treated with 100 ng/mL LPS, 5 × 10⁸/mL sEV-Con, 5 × 10⁸/mL sEV-CC16, or 1 μg/mL rCC16 for 24 h. The amount of released IL-1β (D), TNF-α (E), CXCL-1 (F), and CXCL-2 (G) in culture media were detected using ELISAs. Results represent mean ± SD of three independent experiments and the data were analyzed by a one-way ANOVA followed by Tukey’s HSD. ∗∗p < 0.01.