Fig. 5

Effect of CgCKB1 and CgCKB2 on interaction with host cells. (A) After co-incubation of fungi with RAW264.7 macrophages or PMA-treated THP-1 cells for 2 h, the cells were lysed with 0.05% Triton X-100 to release the fungi, and the phagocytosis rate was defined as the number of fungi phagocytosed by macrophages after 2 h to the number of fungi before co-incubation. (B) After cocultured with macrophages for 24 h, survival upon phagocytosis was measured as described above. The ratio of the intracellular yeast cells after 24 h of coculture to that after 2 h coculture was defined as fold replication. (C) Epithelial Caco-2 cells were cocultured with CgCKB1 or CgCKB2 null mutants, respectively. Δepa1 which exhibited deficient adhesion ability was used as a control. (D) Log-phased yeast cells were seeded in a 24-well plate for biofilm formation assay. Crystal violet [0.4% (w/v)] was used for staining mature biofilms. The destaining solution was measured for absorbance at 595 nm. Wells without yeast cells were used as background. CBS138 was the used as the WT and the knockout strains were generated using CBS138 as the parent. Experiments were performed three times. Error bars show standard deviation. Comparisons were performed using one-way ANOVA followed by Tukey test, and asterisks indicate statistically significant differences (*** p < 0.001, **** p < 0.0001).