Fig. 2.

HeLaS/POZnSurvivin cells secrete Survivin and Hsp70-containing exosomes. a Exosome presence, measured as AChE activity from either 24 h control media or conditioned medium fractions. The 110,000g HeLaS/POZnSurvivin pellets were defined for AChE activity as described in the “Methods and materials”. Each fraction was evaluated by colorimetry. Values represent the means of three media control samples and nine conditioned medium samples. *** P <0.001. b Exosomes were characterized from 24 h HeLaS/POZnSurvivin conditioned medium using electron microscopy from both nonconditioned (left) and conditioned medium (right) respectively. c Immunoelectron microscopy on anti-Survivin- and anti-Hsp70-stained cryosections of HeLaS/POZnSurvivin cells shows that Survivin and Hsp70 localization in the exosome. Immunogold nanoparticles of 10 nm were conjugated to anti-Survivin pAb while 5 nm nanoparticles were conjugated to anti-Hsp70 mAb. Exosomes are cup-shaped and 50–150 nm in size. Bar 100 nm