Fig. 5.

Host cell actin dynamics is required to promote ΔMyoA zoite entry through PM protrusions that do not promote the formation of macropinosomes but enable the folding of a typically ROP2-positive vacuole into which Toxoplasma is forced. a, b Graphs showing the entry rate of ΔMyoA zoites in (a) U2OS and (b) ARPE-19 cells. Columns represent fold of invasion by reference to appropriate control depending on the presence of DMSO or not including (a) 4 to 6 independent assays, and (b) 1 assay; all assays performed in triplicate for each parameter. Total numbers of infected cells relative to total number of scanned cells are indicated on top of each column, while the fold values are marked in white within each column. c, d Maximal projections of images showing tachyzoites interacting with (c) HFF and (d) ARPE-19 cells in presence of 10-kDa fluorescent dextran (Dx, red). Samples were stained for the parasite rhoptry resident protein (ROP2, green) following cell fixation and permeabilization. Frames in the bottom panels (c, d) show images taken at the indicated angles from the 3D reconstructed z stacks. Note the ROP2-positive signal in the forming vacuole surround the entering ΔMyoA zoite and the lack of Dx-positive signal within the PV space