Fig. 5: RT + IL/aC@RBAH elicits robust antitumor efficacy in orthotopic 4T1 breast tumors.

a, b Whole-animal in vivo bioluminescence imaging (a) and corresponding quantification (b) of orthotopic 4T1-luciferase (4T1-luc) tumor-bearing mice after different treatments. c, d Average tumor volume changes (c) and individual tumor growth kinetics (d) of 4T1-luc tumor-bearing mice after different treatments. CR complete tumor regression. e Survival curves of orthotopic 4T1-luc tumor-bearing mice after different treatments. f, g H&E staining of orthotopic 4T1 tumors after different treatments (f) and corresponding tumor necrosis analysis (g) (n = 3 independent experiments). Scale bar, 500 μm. h, i Ki67 immunofluorescence staining (green, Ki67; blue, DAPI) of orthotopic 4T1 tumors after different treatments (h) and corresponding quantification of tumor cell proliferation (i) (n = 3 independent experiments). Scale bar, 100 μm. j Representative flow cytometry plots and quantifications of intratumoral cytotoxic T lymphocytes (CD8⁺ in CD3⁺ cells) in orthotopic 4T1 tumors after different treatments. k–m Quantitative analyses of the intratumoral antigen-specific cytotoxic T lymphocytes (CD8⁺IFN-γ⁺ cells) (k), Th1 cells (CD4⁺IFN-γ⁺ cells) (l), and Tregs (CD4⁺CD25⁺ cells) (m) among CD3⁺ cells in orthotopic 4T1 tumors after different treatments. n–p Quantitative analyses of the ratios of CD8⁺ T/Treg (n) and Th1/Treg (o) and the populations of NK cells (CD3⁻CD49b⁺ in CD45⁺ cells) (p) in orthotopic 4T1 tumors after different treatments. q Quantification of IFN-γ⁺ NK cells in orthotopic 4T1 tumors after different treatments. r Quantification of cDC1 (CD103⁺ cells) and cDC2 (CD11b⁺ cells) among CD11c⁺MHC Ⅱ⁺ cells in TDLNs of orthotopic 4T1 tumor-bearing mice post different treatments. G1, Saline; G2, RT; G3, RT + RBAH; G4, RT + aC@RBAH; G5, RT + IL@RBAH; G6, RT + IL/aC@RBAH. Experiments in (f, h) were independently repeated three times with comparable results. Data in (b, c, g, i, j–r) were presented as mean ± SD. n = 5 mice per group were used in (b–e). n = 3 mice per group were used in (f–r). Statistical significance was determined using two-way ANOVA (b, c) and two-sided unpaired student’s t-test (g, i, j–r). Source data are provided as a Source Data file.