Salmonella and S. aureus Escape From the Clearance of Macrophages via Controlling TFEB

Abstract

Phagosome- and xenophagosome-lysosome systems play a critical role in the defense of pathogenic bacteria, such as <i>Salmonella</i> and <i>S. aureus</i>, in macrophages. A great part of the bacteria escapes from the digestion and can survive through some mechanisms that are still poorly understood and which require further exploration. Here we identified that <i>Salmonella</i> inhibited the expression and activation of TFEB to blunt the functions of lysosomes and defense of clearance by activating caspase-1. The expression and activation of TFEB were enhanced early under the infection of <i>S. aureus</i>, which was followed by shrinkage to weaken lysosomal functions due to the delayed activation of ERK, mTOR, and STAT3. Thus, we have identified novel escape mechanisms for <i>Salmonella</i> and <i>S. aureus</i> to deepen and strengthen our strategies fighting with pathogens.