Figure 2

Reduction of the infection rate in C. parvum-infected MAPK4-KO HCT-8 cells. (A) Effect of host MAPK4 deficiency on C. parvum infection in HCT-8 cells. The infection rates were analyzed by use of an immunofluorescence assay at 24 h post-infection. The number of C. parvum-infected (red; Sporo-Glo) and total host cells (blue; DAPI) was counted by microscopy, and the infection rates are shown as the ratio of C. parvum-infected amongst total host cells and normalized to the WT HCT-8 cells control. ***p < 0.001 (Student’s t test). (B) Transient expression of MAPK4 protein in MAPK4-KO HCT-8 cells. Protein extracts from WT and transfected MAPK4-KO HCT-8 cells were analyzed by western blotting. HaloTag protein (33 kDa) and MAPK4-HaloTag protein (101 kDa) were detected with an anti-HaloTag antibody. (C) Effect of transient expression of MAPK4. MAPK4-KO cells were transfected with empty HaloTag vector or the MAPK4 expression vector, and infected with C. parvum oocysts. The experiment was conducted in 96-well plates. The infection rates were calculated as a proportion of infected cells among total host cells. **p < 0.01, p = 0.9005 (WT—KO + MAPK4), p = 0.9892 (KO—KO + Mock) (Tukey–Kramer method). All graphs show the mean ± SEM for three independent experiments. All images are representative of three independent experiments.