Fig. 3

HELA-Exos stimulate the antigen cross-presentation activity of cDC1s and induce potent CD8⁺ T cell responses in vitro. A and B PBMCs, PBMC-derived DCs, and MCF10A cells were treated with Texs or HELA-Exos for 48 h. Representative images of calcein-AM fluorescence and the quantitative detection of cell viability in different cells. Scale bar, 200 μm. The data are presented as the mean ± SD; n = 6. A t test was performed for statistical analysis (ns: P > 0.05). C Schematic diagram of the establishment of an MDA-MB-231 cell-DC-CD8⁺ T cell coculture model. PBMC-derived DCs were cocultured with MDA-MB-231 cells and pretreated with medium, Hiltonol or HELA-Exos for 24 h. CD8⁺ T cells were added and cocultured for 48 h. D The cells from the coculture model were collected for flow cytometry analysis. The gating strategy for the analysis of CD11c⁺ DCs and CD8⁺ T cells was established, and the expression of CD141, CD1c, HLA-A2, and HLA-DR on DCs were measured. E and F The expression levels of granzyme B, perforin, CD69, and PD1 on CD8⁺ T cells were measured. The data are presented as the mean ± SD; n = 6. A t test was performed for statistical analysis (****: P < 0.0001)