FIG 7.

Extracellular mechanics rule interaction of host cells with bacterial pathogens. (A) Sketch depicting how increased ECM matrix (black mesh) stiffness augments FAK phosphorylation (purple circles) and levels of surface vimentin (blue receptors), thus increasing the adhesion of L. monocytogenes (red rods) to host cells. Panels on the right depict additional ECM stiffness-sensitive processes that could regulate bacterial adhesion onto host cells, including variations of the host cell glycocalyx (gray) and surface roughness. (B) Cartoon depicting how catch bonds between host cell receptors and bacterial surface proteins function. Green arrows indicate the direction of applied force. (C) S. flexneri-infected epithelial cells on a gut-on-chip device compared to cells residing on static Transwells reveal that mechanical deformations and shear flows as well as ECM topography critically impact infection. Adapted from reference 12 with permission from Elsevier.