Fig. 4: The γδTCR-IRF4 axis regulates IL-17A production in lung γδ T cells.

a, b Trajectory map generated using DDTree reduction as implemented through Monocle on a list of 1224 genes with detectable expression and significant dispersion within the Tγδ17 subset. c Pseudotime mapping of gene expression levels within the Tγδ17 subset. d UMAP visualization of IRF4 targeted genes that enrich in the Tγδ17 subset. e Violin plots of the gene expression of Il17a and Cd3g separated by the projected cell state demonstrates that state 4, which has progressed the furthest along pseudotime, is composed of cells that highly express those 2 genes. f IRF4 expression in γδ T cells in mouse lungs at 5 dpi. Shaded histograms depict staining by isotype control antibody. g Representative plot with adjunct histograms gated on lung CD3⁺ live singlets at 5 dpi. h Mouse γδ T cells cells (2 × 10⁶/mL) were stimulated with soluble anti-CD3/CD28 beads (5 μg/mL). Kinetic diagrams showing the merged calcium mobilization in TCRγδ^hi and TCRγδ^low cells. i Plots with adjunct histograms gated on CD3⁺ (left) or CD3⁺ TCRγδ⁺ (right) live singlets of human PBMCs. j IRF4 expression in γδ T cells from human PBMCs. Mean fluorescent intensity, MFI (n = 6). k, l Expression of IRF4 (k) and IL-17A (l) on day 3 of purified γδ T cells from WT or Irf4^−/− mice cultured with plate-bound 1 μg/mL of anti-CD28 and various concentrations of anti-CD3ε (n = 3). m γδ T cells were stimulated with 1 μg/mL of anti-CD28 and 1.5 or 5 μg/mL of anti-CD3ε. ChIP quantification of IRF4 binding to the Il17a promoter was performed using quantitative PCR (n = 3). n IL-17A production in WT and Irf4^−/− bone marrow chimera were analysed at 5 dpi (n = 6). Data are combined from two or three independent experiments and represented as mean ± SEM. P-values were determined using two-tailed unpaired Student’s t-test (j, l, m, n) or one-way ANOVA (k). Source data are included in Source Data file.