Chitin Recognition via Chitotriosidase Promotes Pathologic Type-2 Helper T Cell Responses to Cryptococcal Infection
Fig 5
C. neoformans Chitin Correlates with Type-2 Helper T Cell Response and Subsequent Disease.
(A&B) Cryptococcal cells isolated from lungs at 14 days post-infection and stained with Calcofluor White. Cells were either imaged with epifluorescence microscopy (A) or analyzed by flow cytometry with fluorescence intensity calculated per pixel to determine chitin density within the cell wall (B). (C) Total chitin and chitosan content normalized to dry weight of cryptococccal cells. (D) Flow cytometry plots of CD4+, Foxp3-, CD44+ Cda2+ Th cells expressing Th2 cytokines, IL-5 & IL-13, at 14 days post-infection and (E) the quantification of these plots. (F) Cytokines from lung homogenates of mice 14 days post-infection. (G) IL-5+ IL-13+ antigen-specific Th2 cells from lungs of mice 14 days post-infection without and with intranasal chitin particle treatment. (H) P-value represents log-rank test comparing each survival curve with 10 mice per group to: gpr4Δgpr5Δ vs. KN99α, P<0.0005; gpr4Δgpr5Δ vs. rim101Δ, P<0.0005; KN99α vs. rim101Δ, P<0.0005. (I) Fungal burden in the lungs at 14 days post-infection. Data are presented as the mean +/- standard error with at least 2 independent experiments per group. ** = P < 0.005, *** = P < 0.0005 by Mann-Whitney U or Kruskal Wallis ANOVA. Cda = chitin deacetylase, CCL = chemokine ligand, GlcNAc = N-acetylglucosamine, IFN = interferon, IL = interleukin.