Fig. 8: IV BCG recruits and activates NK and CD8⁺ T cells in an orthotopic lung cancer model.

a Schematic diagram showing treatment strategy. b Frequencies of cellular subsets in the lung (n = 5 mice for PBS IV and n = 6 mice for BCG IV, from one experiment). c Granzyme B expression by immune cell subsets (n = 5 mice for PBS IV and n = 6 mice for BCG IV, from one experiment). d In vitro cytotoxicity of lung NK cells against LLC tumor cells. Pooled from two independent experiments with n = 2 mice per condition in each experiment. e IFN-γ or IL-2 expression by lung CD8⁺ or CD4⁺ T cells (n = 5 mice for PBS IV and n = 6 mice for BCG IV, from one experiment). f Frequency of PD-1⁺ SIINFEKL-specific CD8⁺ T cells in the lungs of mice bearing orthotopic LLC-OVA tumors (n = 5 mice/group, from one experiment). g, Representative IHC staining of NK cells in orthotopic LLC lung tumors. NCR1⁺ cells were quantified inside tumor nodules (n = 21 regions for IV PBS-treated mice and n = 10 regions for IV BCG-treated mice) and adjacent tumor-free tissue (n = 17 regions for IV PBS and n = 13 regions for IV BCG-treated mice). Data comes from one experiment with n = 5 mice for PBS IV and n = 6 mice for BCG IV. h CD8⁺ T cell quantification by IHC in LLC tumor nodules (n = 27 regions for IV PBS-treated mice and n = 10 regions for IV BCG-treated mice) and adjacent tumor-free tissue (n = 21 regions for IV PBS and n = 7 regions for IV BCG-treated mice). Data comes from one experiment with n = 5 mice for PBS IV and n = 6 mice for BCG IV. Scale bars correspond to 50 μm in length (g, h). P values were calculated using two-tailed unpaired Student’s t-test at a 95 % CI (b–h). Data depicted as mean ± SEM. PBS phosphate-buffered saline, IV intravenous, NK natural killer, GZMB Granzyme B.