Shigella are versatile mucosal pathogens that circumvent the host innate immune system

The intestinal mucosa is equipped with multiple innate immune defense systems that sense bacterial infection, transmit alarm signals to the immune system, defeat intruding bacteria, and renew damaged and aging epithelial cells. Nevertheless, mucosal bacterial pathogens have versatile pathogenic mechanisms that modulate the host inflammatory and immune responses, manipulate host cell death and survival signal pathways, and renovate the injured epithelium. These properties enable pathogens to adapt to the intestinal mucosal environment, exploit cellular and immune functions, and facilitate infection. Here we review current topics on host defense mechanisms against bacterial infection and the countermeasures that Shigella use to evade the innate immune system.

► The intestinal mucosa has multiple defense systems that sense bacterial infection.
► Bacterial pathogens have versatile mechanisms that modulate the host defense systems.
► These properties enable pathogens to facilitate infection.
► We review on the mechanisms that Shigella use to evade the innate immune system.