Fig. 6. Effects of global arginase inhibition on different lymphocyte subsets in BALB/c mice infected with P. aeruginosa.

BALB/c mice were infected intratracheally with 2×10⁶ CFU P. aeruginosa incorporated into agarose beads. Mice were either dosed with 0.012g of BEC daily via oral gavage starting 1 day prior to infection or with vehicle control (water). Lungs were lavaged to collect cells from the airways, and excised and digested for assessment of interstitial cellularity. Tracheobronchial lymph nodes draining the site of infection were harvested and processed into single cell suspensions. T lymphocyte populations were analyzed by flow cytometry as depicted in the gating scheme in Fig. 3. (A-C) Numbers of total CD4⁺ T cells, activated CD4⁺ (CD44^hi CD62L^lo) T cells, Th17 (CD4⁺ IL-17⁺ RORγt⁺) lymphocytes, and Th1 (CD4⁺ CXCR3⁺ IFNγ⁺) lymphocytes in the lung interstitium (A), lymph nodes (B), and airways (C) of infected mice on day 2 post-infection. Mean ± 95% CI along with individual mouse values are depicted, with statistical significance defined for P < 0.05 (*) for differences between groups analyzed using repeated-measures ANOVA with Tukey’s test for multiple comparisons. Results are representative of three independent replicates. CFU, colony forming units; BEC, S-(2-Boronoethyl)-L-cysteine hydrochloride; IL, interleukin; ROR, RAR-related orphan nuclear receptor; CXCR3, C-X-C motif chemokine receptor 3; IFNγ, interferon-γ; SD, standard deviation; CI, confidence interval; ANOVA, analysis of variance.