Working model of the mechanism of wetting-induced plasma membrane protrusions by N. meningitidis type IV pili fibers

N meningitidis produces type IV pili as a meshwork of fibers. On adhesion to the host endothelial cell, the high adhesiveness of type IV pili allows “one-dimensional” membrane wetting of the plasma membrane and, thus, remodeling of the membrane alongside type IV pili fibers. As the bacteria proliferate and aggregate extracellularly, plasma membrane protrusions remain attached to type IV pili fibers and end up embedded in a dense extracellular type IV pili meshwork. This complex structure gives microcolony enough mechanical coherence to resist blood flow–generated shear stress. (Source: Charles-Orszag A, Tsai FC, Bonazzi D, et al. Adhesion to nanofibers drives cell membrane remodeling through one-dimensional wetting. Nat Commun 2018;9[1]:4450. Creative Commons Attribution 4.0 International License, creativecommons.org/licenses/by/4.0.)