Outer membrane adhesion factor multivalent adhesion molecule 7 initiates host cell binding during infection by Gram-negative pathogens

摘要

The initial binding of bacteria to host cells is crucial to the delivery of virulence factors and thus is a key determinant of the pathogen's success. We report a multivalent adhesion molecule (MAM) that enables a wide range of Gram-negative pathogens to establish high-affinity binding to host cells during the early stages of infection. MAM7 binds to the host by engaging in both protein–protein (with fibronectin) and protein–lipid (with phosphatidic acid) interactions with the host cell membrane. We find that MAM7 expression on the outer membrane of a Gram-negative pathogen is necessary for virulence in a nematode infection model and for efficient killing of cultured mammalian host cells. Expression of MAM7 on nonpathogenic strains produced a tool that can be used to impede infection by Gram-negative bacterial pathogens. Targeting or exploiting MAM7 might prove to be important in combating Gram-negative bacterial infections.