Fig. 1

RDEs enriched with tumor specific-antigen and HSP70 could captured by MDSCs. a Typical morphologies and sizes of RDEs were identified by transmission electron microscopy (TEM). b Western blot was used for detecting the expression of exosomal biomarkers and cellular protein or c Renal-specific antigens (G250) and immuno-modulators (HSP70) in RenCa cell and RDEs. Thirty microgram of total protein was loaded for RenCa cell and RDEs, respectively. d The separation rate of MDSCs was verified by flow cytometry. The cellular morphology and characterization of MDSCs were observed by microscope (e) and immunofluorescence assay analysis (f). g, i Schematic representation of the experiment in vitro and in vivo. h Representative phagocytosis of PKH67-labelled RDEs by MDSCs at 0 h, 6 h or 12 h in vitro. j Phagocytosis of RDEs by splenetic MDSCs in vivo at non-injected and 24 h or 48 h after intravenous injection with PKH67-labelled RDEs. The image was observed by confocal microscopy. Green, PKH67-labelled RDEs; Blue, DAPI. k Representative graph of fluorescence of MDSCs detected with flow cytometry as described in (h). l Representative graph of fluorescence of MDSCs from mouse spleen after tail intravenously injected PKH67-labeled RDEs as described in (j). All experiments were repeated at least three times and three mice were in each group