Fig. 3

Exo^NM act via the cells of monocytic lineage. a–c Mice were treated with control or clodronate liposomes to eliminate monocytes/macrophages, then pre-conditioned with exosomes (10 μg per mouse) and used in the extravasation assay as described above. a Macrophage depletion was assessed by F4/80 IF (n = 3, scale bar, 100 μm) or CD11b IF (Supplementary Fig. 5). b, c The inhibition of B16F10 extravasation by Exo^NM was diminished by monocyte depletion. Representative lung images (5× magnification) are shown in b (scale bar, 100 μm), and quantitative analysis is shown in c (n = 5 untreated, n = 6 Exo^M, Exo^NM, five random images analyzed per animal). *P < 0.05 and **P < 0.01 calculated by two-tailed t-test in pairwise comparison. Median values and range are shown. d RAW 264.7 macrophages were treated with 10 μg ml⁻¹ Exo^M or Exo^NM and their morphology was assessed by time-lapse microscopy. Representative frames are shown. e Engulfment of fluorophore-tagged melanoma cells (red) by RAW264.7 macrophages after treatment with 1 μg ml⁻¹ of Exo^M or Exo^NM (Fluorescence and Nomarski image overlays). f Quantification of phagocytosis of the FCSE-tagged melanoma cells by RAW 264.7 macrophages after treatment with Exo^M or Exo^NM at indicated concentrations. A minimum of three random images were analyzed per condition. **P < 0.01 and ***P < 0.001, respectively, as was calculated by Tukey’s multiple comparison test with Bonferroni post-test. Mean and s.e.m. values are shown