Figure 4. CPL1 promotes arginase-1 expression in pulmonary interstitial macrophages and is required for virulence.

(a) FACS subgating on CD45+YARG+ lung cells from arginase-1-YFP (YARG) mice infected intranasally with 5x10⁴ CFU WT C. neoformans for 10 days. (b) Representative histogram of YARG expression in lung interstitial macrophages from mice injected intranasally with either saline or 5x10⁴ CFU WT C.n. for 10 days. (c) Quantification of YARG expression by FACS on interstitial macrophages from mice injected intranasally with either saline (N=5 mice), WT (N=11 mice), cpl1Δ (N=14 mice), or qsp1Δ (N=5 mice) Kn99a (5x10⁴ CFU) for 10 days; statistical significance determined by one-way ANOVA with Bonferroni test. (d) Kaplan-Meier survival curve analysis of mice infected with WT (N=10mice) or cpl1Δ C.n. (N=10 mice); ****p < 0.0001 by Mantel-Cox test. (e) Representative histogram (left) and quantification of YARG expression on WT, Il4ra^−/−, or Stat6^−/− (all N=4 mice) infected for 10 days as in (a). (f) CFUs from lungs of the indicated mouse genotypes (N=6 mice for each genotype) infected for 10 days with either WT or cpl1Δ strains; statistical significance determined by one-way ANOVA with Bonferroni test. (g) Arginase-1 FACS on lung IMs from WT or Tlr4^−/− mice infected as in (a); statistical significance determined by unpaired two-sided T-test. (h) Representative FACS histograms of C.neoformans-mCherry expression in alveolar macrophages (left) or interstitial macrophages (right) after 10 days of infection. (i) Representative FACS histograms of C.neoformans-mCherry expression in interstitial macrophages from YARG mice gated on YARG-negative IMs (left) or YARG-positive IMs (right). *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001