The spectrin cytoskeleton is required for efficient intestinal bacterial infections

Crucial aspects of bacterial pathogenesis such as the invasion of host cells and cell‐to‐cell transmission require the hijacking of host cell cytoskeletal systems. Although much work has examined the role of the actin cytoskeleton during numerous bacterial infections, the involvement of the spectrin cytoskeleton has remained overlooked. The spectrin cytoskeleton is required for many cellular processes including cell motility, organization of the plasma membrane and epithelial cell polarization. To determine whether this cytoskeletal system influenced microbial infections we tested the hypothesis that bacterial pathogens control the spectrin cytoskeleton as part of their disease processes. To test this hypothesis we utilized cell biological techniques including the immunolocalization of spectrin cytoskeletal components and RNA interference, and coupled these analyses with microbiological techniques such as wild‐type and mutant bacterial infections, invasion assays and colonization experiments. We found that the spectrin cytoskeletal network was integral for Salmonella , Listeria , Shigella and pathogenic E. coli infections. We showed that host cell invasion and the generation of bacterial motility structures during infections required spectrin cytoskeletal components and knockdown of specific spectrin‐associated proteins haulted Listeria , Shigella and Salmonella internalization as well as pathogenic E. coli attachment to host cells, thus impeding the infections. These findings demonstrate that the spectrin cytoskeleton is essential for bacterial pathogenesis and could be used as a target for future therapeutics. This work was funded through NSERC and the CIHR. Grant Funding Source : CIHR and NSERC