Branched Polyethylenimine-Superparamagnetic Iron Oxide Nanoparticles (bPEI-SPIONs) Improve the Immunogenicity of Tumor Antigens and Enhance Th1 Polarization of Dendritic Cells

Figure 3

Damage-associated molecular pattern (DAMP) production by dying tumor cells induced by apoptotic pathway. (a) Expression of Hsp70 and Hsp90 on 2 h postirradiated cells, 16 h postirradiated cells, and bPEI-SPION 2 h postirradiated cells was measured by flow cytometry. Hsp70 and Hsp90 (shaded histogram) production compared with isotype controls (open histogram). 2 h postirradiated cells and bPEI-SPION 2 h postirradiated cells showed high percentage of positive cells on Hsp70 and Hsp90 expression. (b) Danger signal (Hsp70, Hsp90, and HMGB1) release from the cells was analyzed by Western blotting. bPEI-SPION 2 h postirradiated cells and 2 h postirradiated cells produced higher levels of the three danger signals compared with 16 h postirradiated cells. Data are representative of three independent experiments.

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