<p>(A) Detection of BAT3 expression on exosomes by electron microscopy {left panel: gold antibody control (140000×) and right panel: exosomes stained with anti-BAT3 antibody (140000×)}. (B) Western blotting to detect BAT3, Hsp70, Lamp-2 and CD9 in exosomal fractions (30 µg) and lysate (10 µg) of 293T cells and iDCs. (C,D) FACS analysis to detect BAT3 and various surface markers on exosomes, that were purified from iDCs (C) or 293T cells (D) that were immobilized to latex beads. Grey background represents isotype control. (E) FACS analysis of exosomes derived from control transfected (wt) or BAT3-transfected (BAT3) 293T cells revealed over-expression of BAT3 on the exosomal surface. Specific binding of anti-BAT3, NKp30-Ig and NKp46-Ig was detectable. Grey histograms: background (secondary antibody) staining of beads coated with exosomes. (F) Western blot analysis demonstrates that the enhanced secretion of BAT3 into the supernatant obtained from tumor cells (293T) when treated with heat shock (HS, lane: 3) or left untreated (UT, lane: 2). Lanes 4 and 5 demonstrate the co-immunoprecipitation of BAT3 by using either a polyclonal BAT3 antibody (4<sup>th</sup> lane) or a monoclonal Ab against Hsp70 (5<sup>th</sup> lane). The western blot is stained for BAT3. Lane 1 (M) indicates the marker.</p
