Figure 1

Association of LMP1 and galectin 9 with various types of extra-cellular particles released by C15 NPC cells. A) Western blot analysis of the pellets obtained by differential centrifugation of C15 and C17 cell conditioned medium (14 μg/lane). B) Electron microscopy of 3 sequential pellets obtained by differential centrifugation of C15 cell conditioned medium. P4 (10,000 g), P5 (40,000 g) and P6 (100,000 g) are shown at magnification 90,000, 90,000 and 135,000 respectively. Arrowheads point to retroviral particles (P4 and P5). White arrows point to vesicles of 70 nm diameter compatible with exosomes (P6). The apparent heterogeneity of vesicle sizes in pellet P6 results in a large extent from the fact they are seen in a planar section with some vesicles being cut tangentially. C) Western blot detection of the DRα chain and CD63 protein in C15 cells (30 μg) and P6 (14 μg) extracts (for CD63, gel separation was done in non-reducing conditions as previously reported [29]).