Fig. 4: Candidalysin promotes oral colonization by enabling C. albicans to overcome the barrier of the stratum corneum.

a, LDH release from IMOK cells in response to SC5314^WT, SC5314^ece1Δ/Δ 101^WT and 101^tetOff_ECE1 after 24 h of incubation (n = 3 or 6 per group). Each symbol represents an individual well with mean per group ± s.d. Data are from one representative of at least five independent experiments. b, Ratio of ECE1 expression by SC5314 versus 101 after 24 h of exposure to IMOK keratinocytes, HEEs or murine tongue tissue (in vivo). Each symbol represents an independent experiment (mean of 1–3 replicates each) with mean ± s.d. per group. c, LDH release from IMOK cells in response to 101^WT or 101^tetOff_ECE1 (1 × 10⁵ yeast cells per well) in direct contact (cc) or transwell (TW) for 24 h (n = 3 or 4 per group). Each symbol represents an individual well with the mean per group ± s.e.m. Data are pooled from 2 independent experiments. d–f, C57Bl/6 WT mice were associated with 101^WT or 101^ece1Δ/Δ for 2 h; tongues were collected and incubated for 6 h (d,e) or 22 h (f) in a humid chamber at 37 °C, 5% CO₂. Representative PAS-stained tongue tissue sections (d,f) and quantification of fungal foci outside the host, in the stratum corneum or in nucleated epithelial layers (e). Each symbol represents the percentage of all events per category and section from an individual mouse (>28 events per section); n = 3 animals per group with mean ± s.d. per group. g,h, Representative PAS-stained tongue tissue sections from C57Bl/6 WT mice (g) or Il17rc^−/− mice (h) associated with 101^WT or 101^ece1Δ/Δ for 7 days (g) or 19 days (h). The yellow lines indicate the boundary between the stratum corneum and stratum granulosum. The black arrows indicate fungal elements. Data are pooled from at least 2 independent experiments. i–j, The tongue of C57Bl/6 mice was (+) or was not (−) mechanically disrupted before the association with 101^ece1Δ/Δ Tongue CFU on day 1 (i) and representative histology sections of tongues at 2 h plus additional incubation in a humid chamber at 37 °C, 5% CO₂, for 6 h (j); n = 4 pooled from 2 independent experiments with mean ± s.e.m. The statistical significance of differences between groups was determined by two-way ANOVA (a,c,e) or ordinary one-way ANOVA (b).