FIG. 9.

Helicobacter pylori strain V225d induces the formation of the “hummingbird phenotype” in AGS cells. AGS cells were cultured under basal conditions (control) or for 24 h with H. pylori strain 43504, V225, or V225-RE. (A) Phase-contrast microscopy imaging of AGS cells. Bar, 20 μm. (B) Fluorescence microscopy imaging of the actin cytoskeleton and focal adhesions of AGS cells. Shown are merged images of the fluorescent staining of F-actin (with Alexa Fluor 568-labeled phalloidin, red), vinculin (with primary and Alexa Fluor 488-labeled secondary antibodies, green), and DNA (with Hoechst 33342 compound, blue). Control cells are organized in clusters of polygon-shaped cells, with focal adhesions at the cell periphery, few actin stress fibers, and no lamellipodia. Arrows indicate cells after coculture that exhibit cytoskeleton remodeling, with dissociation of cell clusters, loss of the polygon shape, cellular elongation with lamellipodia and stress fiber formation, and an increase in focal-adhesion number and size, defining the hummingbird phenotype. Bar, 10 μm.