Promotes Its Own Survival in B Cells by Inhibiting Autophagy.

is a Gram-negative bacterium known to be the major cause of gastrointestinal diseases and systemic infections. During infection of murine B cells, activates the PI3K/Akt pathway through its effector, SopB. This signaling pathway induces the downregulation of NLRC4 transcription, resulting in reduced secretion of IL-1β. Thus, -infected B cells do not progress to pyroptosis; consequently, the bacteria can survive inside these cells. However, the mechanism by which evades the control of B cells has not yet been elucidated. In this study, we found that SopB activates mTORC1, which is necessary for bacterial survival, since B cells cultured with the mTORC1 inhibitor rapamycin and B cells lacking raptor can control infection. A similar result was observed in B cells when they were infected with the SopB mutant (Δsopb). also promoted the phosphorylation of the ULK1 complex at serine 757 (Ser757) by mTORC1, resulting in decreased levels of LC3-II in infected B cells. In this study, we did not observe these results when B cells were infected with Δsopb . Our results demonstrated that survival within B cells depends on the inhibition of autophagy by mTORC1 activation.