Pseudomonas aeruginosa interacts with epithelial cells rapidly forming aggregates that are internalized by a Lyn-dependent mechanism.

PAOLA LEPANTO; DAVID BRYANT; JÉSSICA ROSSELLO; ANIRBAN DATTA; KEITH MOSTOV; ARLINET KIERBEL

CELLULAR MICROBIOLOGY (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2011 vol. 13 p. 1212 - 1222

1462-5814

Growing evidence is pointing to the importance ofmulticellular bacterial structures in the interactionof pathogenic bacteria with their host. Transitionfrom planktonic to host cell-associated multicellularstructures is an essential infection stepthat has not been described for the opportunistichuman pathogen Pseudomonas aeruginosa. Inthis study we show that P. aeruginosa interactswith the surface of epithelial cells mainly formingaggregates. Dynamics of aggregate formationtypically follow a sigmoidal curve. First, a singlebacterium attaches at cell–cell junctions. This isfollowed by rapid recruitment of free-swimmingbacteria and association of bacterial cells resultingin the formation of an aggregate on theorder of minutes. Aggregates are associated withphosphatidylinositol 3,4,5-trisphosphate (PIP3)-enriched host cell membrane protrusions. Wefurther show that aggregates can be rapidly internalizedinto epithelial cells. Lyn, a member of theSrc family tyrosine kinases previously implicatedin P. aeruginosa infection, mediates both PIP3-enriched protrusion formation and aggregateinternalization. Our results establish the firstframework of principles that define P. aeruginosatransition to multicellular structures during interactionwith host cells.