Fig. 3

GITR costimulation rescues low-affinity D^b/NP_366–374-specific CD8 T cells. a, d GITR^+/+:GITR^−/− mixed bone marrow chimeras were generated and infected as described in Fig. 1. b, e Wild-type C57BL/6 (GITRL^+/+) mice were co-housed with GITRL ^exon2Δ/Δ mice from weaning and infected i.n. with influenza A/HK-X31 and analyses were done at day 9 p.i. c, f LysM-Cre^+/+ and LysM-Cre^−/− GITRL^exon2fl/fl littermates were infected i.n. with influenza A/HK-X31 and analyzed at day 9 p.i. The MFI of D^b/NP_366–374 tetramer binding or CD3 binding to tetramer⁺ CD8 T cells in the lung, mLN, and spleen of GITR^+/+ and GITR^−/− donor origin was determined on day 10 a, of GITRL^+/+ and GITRL ^exon2Δ/Δ mice on day 9 b, and of LysM-Cre^+/+ and LysM-Cre^−/− GITRL^exon2fl/fl mice on day 9 c. MFI of D^b/PA_224–233 tetramer binding or CD3 binding of tetramer⁺ CD8 T cells in the lung, mLN, and spleen of GITR^+/+ and GITR^−/− donor cells was determined on day 10 d, of GITRL^+/+ and GITRL ^exon2Δ/Δ mice on day 9 e, and of LysM-Cre^+/+ and LysM-Cre^−/− GITRL^exon2fl/fl mice on day 9 f. Representative histogram plots are shown below the summary plots for each set of data. Each symbol represents an individual mouse, with bars indicating mean ± SEM. Statistical analyses performed using Wilcoxon test a and d or Mann–Whitney test b, c, e, and f. Data from a and d pooled from 12 individual chimeric mice with two independent experiments. Data from b and e were pooled from three independent experiments with a total of 6–7 mice per group. Data from c and f were pooled from two independent experiments with a total of eight mice per group