Fig. 4: IFN-γ stimulates antigen enrichment in a MHC-I dependent manner.

a Representative histograms showing OVA presentation on WT and B2m^−/− B16-OVA cells upon IFN-γ treatment. b The abilities of CM and AECM from WT and B2m^−/− B16-OVA cells (2 μg/mL) to stimulate OT-I T-cell proliferation (n = 3 independent experiments/group). c–e B16-OVA tumour growth curves were shown (c, n = 5 mice/group). At day-29 post tumour inoculation, PBMCs were re-stimulated and the IFN-γ secretion by CD8⁺ T-cells were determined by ICS (d, n = 4 mice/group), and tumour infiltrating CD8⁺ T-cells (e, n = 4 mice for AECM@PC7A group, n = 5 mice for other groups) were measured. f Representative histograms showing MHC-I expression on WT and B2m^−/− MC38 cells upon IFN-γ treatment. MC38 tumour growth curves were shown (g, n = 5 mice/group). At day-28 post tumour inoculation, the IFN-γ secretion by CD8⁺ T-cells in PBMCs upon re-stimulation with Adpgk (h) or Rpl18 (i) neoantigen peptide was determined by ICS, and tumour infiltrating CD8⁺ T-cells (j) were measured (n = 5 mice/group). k B16-OVA tumour-bearing mice were i.t. vaccinated (black arrows), and received i.p. treatment of CD4, CD8 or isotype antibodies. Tumour growth curves were shown (n = 5 mice/group). l–n Splenic DCs were treated with B16-OVA derived nanovaccines (20 μg/mL) for 18 h, and MHC-I acquisitions was determined. Representative scatter plots (l) and the levels of acquired MHC-I as calculated by subtracting the MHC-I MFI from that of the untreated cells (m) for B2m^−/− DCs were shown. The treated DCs were harvested and co-cultured with OT-I T-cells for 48 h, CD8⁺ T-cell proliferation (n) were determined (n = 3 independent experiments/group). o Splenic DCs were treated with indicated PC7A vaccines for 18 h. The treated DCs were harvested and co-cultured with OT-I T-cells for 48 h, CD8⁺ T-cell proliferation was measured (n = 3 independent experiments/group). p WT or B2m^-/- mice were adoptively transferred with 2 × 10⁵ OT-I T-cells, followed by s.c. vaccination 18 h later. The percentage of OT-1 CD8⁺ T-cells (CD8⁺OVA Tetramer⁺) in spleens was determined (n = 3 mice/group). In (b–e, g–k, m–p), q representative data from three independent experiments are presented as means ± s.e.m. Source data are provided as a Source Data file.