Fig. 3: Stimulation of T cell function in the lung by IV BCG.

a Schematic diagram showing treatment strategy for (b–e). b, c IFN-γ or IL-2 expression by lung CD8⁺ or CD4⁺ T cells in B16-F10 tumor bearing mice at day 20, n = 9 mice/group for IFN- γ and n = 5 for IL-2, pooled from two independent experiments. d Expression of Granzyme B on lung tissue-infiltrating CD8⁺ T cells; representative contour plots for the identification of lung-tissue infiltrating CD8⁺ T cells (CD45 IV^-) and for Granzyme B expression are shown, n = 6 mice/group, pooled from two independent experiments. e Expression of T-bet and GATA3 on lung tissue-infiltrating CD4⁺ T cells, n = 6 mice/group, pooled from two independent experiments. f Schematic diagram showing treatment strategy for panels (g–j). g, h Quantification of CD44⁺ gp33-specific CD8⁺ T cells in the lungs and spleens of mice bearing B16-F10.gp33 lung tumors at day 20. Representative contour plots are shown. Lung (g): n = 10 mice/group, pooled from two independent experiments. Spleen (h): n = 5 mice/group, from one experiment. i Granzyme B expression by gp33-specific CD8⁺ T cells in the lung, n = 5 mice/group, from one experiment. j Cytotoxicity exerted by splenocytes isolated from mice bearing B16-F10.gp33 lung tumors against target B16-F10-ZsGreenLuc or LLC-ZsGreenLuc tumor cells. Percentage cytotoxicity was calculated in reference to luminescence emitted by cells without splenocytes, n = 6 mice/group, from one experiment. k Schematic diagram showing experimental setup and follow-up of B16-F10 tumor growth in Rag1^−/− mice reconstituted with splenocytes from the indicated donor mice, n = 4 BCG IV (tumor-free), n = 6 tumor-bearing + PBS IV, n = 6 tumor-bearing + BCG IV. P values were calculated using two-tailed unpaired Student’s t-test at a 95 % CI (b–e, g–j) or two-way ANOVA (k). Data depicted as mean ±  SEM (b–e, g–k). PBS phosphate-buffered saline, IV intravenous, SC subcutaneous.