Fig. 3

MR1^−/− mice show enhanced weight loss and mortality in response to severe influenza. a Body weight loss expressed as a percentage after infection with 100 PFU PR8 virus. WT (n = 7) and MR1^−/− data (n = 9) are representative of four experiments with similar results. Adoptive transfer (n = 6), performed once, used 1 × 10⁶ pulmonary MAIT cells from WT mice previously infected with 10⁶ CFU S. Typhimurium BRD509 for 7 days to expand the MAIT cell population. Cells were transferred 1 week prior to influenza virus infection. Graphs show mean weights ± SEM for surviving mice, with individual plots for animals which succumbed to infection. b Survival curves after intranasal infection with 100 PFU of PR8, showing combined data from one (MR1^−/− + MAIT cells, n = 6) to four experiments (WT, n = 36; MR1^−/−, n = 41). Survival curves compared using log-rank (Mantel–Cox) tests. c Titres of infectious virus in clarified lung homogenates at 3 and 5 dpi, expressed as plaque-forming units (PFU). Data are from a single experiment. d Absolute numbers of alveolar macrophages and e MR1-5-OP-RU tetramer-negative T cells in single cell lung suspensions prepared from uninfected animals and from animals at 3, 5 and 7 dpi. Data are combined from three experiments with similar results. f Total protein concentration in cell-free BAL supernatants at days 3 and 5 post-infection. Graphs show means ± SEM. *Mann–Whitney P < 0.05; ***P < 0.001