Fig. 2: Lung γδ T cells protect against pdmH1N1 by producing IL-17A.

a Representative plots showing IL-17A⁺ cells (left) and cumulative data (right) showing frequencies of IL-17A⁺ γδ T cells in IL-17A⁺ population (n = 10) and cell numbers of γδ T cells (n = 10, 6, 6, 10) at 5 dpi. b Plots (left) and cumulative data (right) showing IL-17A⁺ γδ T cells at 5 dpi (n = 10, 6, 6, 10). c Plots (left) and cumulative data (right) showing IL-17A⁺ γδ T cells at 5 dpi (n = 10). d Flow cytometry analysis of Vγ chain usage and IL-17A expression by γδ T cell subtypes (n = 6). e–g PdmH1N1-infected Il17a^−/− mice at 1 dpi were i.v. transferred with 2 × 10⁶ γδ T cells purified from infected wild-type (WT) or Il17a^−/− mice at 4 dpi. Kaplan–Meier survival rate (e) and body weight (f) were monitored (n = 14, 12, 12, 11). g H&E histology (left) and scoring (right) of lungs at 5 dpi (n = 3). Scale bar, 40 μm. h, i Mice at 5 dpi were i.v. injected with 40 μg of FITC-anti-CD45 antibody 10 min before killed and perfused (n = 5). h Plots (left) and cumulative data (right) showing lung circulating (CD45⁺) and parenchyma-associated (CD45⁻) IL-17A⁺ γδ T cells. i Plots (left) and cumulative data (right) showing frequencies of CD69⁺CD103⁺ cells. j Mice received an i.p. injection of 1 μg of PTX immediately after infection. At 4 dpi, mice were injected with FITC-anti-CD45 10 min before they were killed and analyzed (n = 5). k Mice received ThX or Mock-ThX 1 day before infection (n = 5). Plots (left) and cumulative data (right) showing IL-17A⁺ γδ T cells at 4 dpi. l Schema of parabiosis (left) and chimerism of Tγδ17 cells (right) (n = 8, 6). Data are combined from two or three independent experiments and presented as mean ± SEM. P values were determined using two-tailed unpaired Student’s t-test (c, h–l), Gehan-Breslow-Wilcoxon Test (e), one-way ANOVA (a, b, g), or two-way ANOVA (f). Source data are included in Source Data file.