Fig. 5

In the absence of competition, GITR is required for optimal CD8 T-cell response and CD8 Trm formation but dispensable for the CD4 T-cell response and CD4 Trm formation in response to influenza virus. GITR^+/+ and GITR^−/− littermates were infected i.n. with influenza A/HK-X31 and killed at day 9 p.i. a, c, e or at day 30 p.i. b, d. a Total number of CD8 T cells, D^b/NP_366–374-specific, and D^b/PA_224–233-specific CD8 T cell in the lung. b Total number of polyclonal CD69⁺ CD103⁺ CD8 Trm, D^b/NP_366–374-specific, and D^b/PA_224–233-specific CD69⁺ CD103⁺ CD8 Trm in the lung parenchyma. c Total number of CD4 T cells, CD44^hi T-bet⁺ Th1, and CD25^hi FoxP3⁺ Treg in the lung. d Total number of CD69⁺ CD11a^hi CD4 Trm in the lung parenchyma. e Total number of CXCR5⁺ PD-1⁺ FoxP3⁻Tfh in the mLN and spleen. Each symbol represents an individual mouse, with bars indicating mean ± SEM. Statistical analyses performed using Mann–Whitney test. Data from a were pooled from four independent experiments with a total of 13 to 14 mice per group. Data from c, e were pooled from three independent experiments with a total of 6 to 7 mice per group. Data from b, d were pooled from three independent experiments with a total of 10 to 11 mice per group