Fig. 8: IL-1RA produced by Ba LPS-challenged PD-L1⁺Sca-1⁺ neutrophils inhibits T cell responsiveness.

a sPLS-DA loading plots of cytokines/chemokines measured at admission in serum of acute, acute with relapse, and chronically infected brucellosis patients and healthy donors. Healthy donors n = 20; Brucellosis patients: Acute n = 20, Acute with relapse n = 6, Chronic n = 5. b IL-1RA ELISA values in omenta from C57BL/6 mice at 48 h (red) or 72 h (orange) after Ba-wt LPS or PBS (black) administration. Mean of pooled data ± SD. 1-3 mice/group, n = 3. Significant differences are shown (one-way ANOVA followed by Tukey’s multiple comparison test; F = 17.41, DF = 14). No p-value, non-significant. c IL-1RA ELISA values, normalized to omentum, from PMA/ionomycin-stimulated (left, magenta) or anti-CD3/anti-CD28-stimulated (right, red) T cells cocultured or not (black) with Ba-wt LPS-challenged peritoneal neutrophils (pN) at 1:1 ratio for 48 h. 1 well/condition, n = 4. nd, non-detected. Mean ± SD. Significant differences are shown (two-sided unpaired Welch’s t test; PMA/Ionomycin, t = 33.86, DF = 3.012; anti-CD3/anti-CD28, t = 5.164, DF = 3.001). d Absolute numbers of Ly6G⁺ neutrophils secreting IL-1RA⁺ (left) and % of PD-L1⁺Sca1⁺ among those (right), from peritoneal fluid exudates at 48 h post-challenge of C57BL/6 mice with Ba-wt (red) or Ec (blue) LPS, or PBS (black), and analyzed by flow cytometry. Each symbol represents one animal. Mean from pooled data ± SD. 2-3 mice/group, n = 3. Significant differences are shown (left, one-way ANOVA with Tukey’s multiple comparison test, F = 22.42, DF = 21; right, multiple comparison Kruskal-Wallis test, followed by post-hoc Dunn’s test). No p-value, non-significant. e Absolute numbers of proliferative cells in anti-CD3/CD28-stimulated CTV-fluorescently labeled T cells cultured for 72 h with (blue) or without (black) recombinant IL-1RA. Mean ± SD. 1-2 wells/condition, n = 3. Significant differences from mock-treated anti-CD3/CD28-stimulated cells are shown (One-way ANOVA followed by Dunnet’s multiple comparison test; CD4⁺ F = 95.07, CD8⁺ F = 76.77; all DF = 16). f MFI of CD69 (left) and CD25 (right) in proliferative cells in (e). Mean ± SD. 1-2 wells/condition, n = 3. Significant differences from mock-treated anti-CD3/CD28-stimulated T cells are shown (One-way ANOVA followed by Dunnet’s multiple comparison test; CD69: CD4⁺ F = 142.8, CD8⁺ F = 91.25; CD25: CD4⁺ F = 30.02, CD8⁺ F = 18.83; all DF = 16). Source data are provided as a Source Data file.