Listeria monocytogenes strain-specific impairment of the TetR regulator underlies the drastic increase in cyclic di-AMP secretion and beta interferon-inducing ability.

ABSTRACT: Among a number of laboratory strains of Listeria monocytogenes used in experimental infection, strain LO28 is highly capable of inducing robust beta interferon (IFN-β) production in infected macrophages. In this study, we investigated the molecular mechanism of the IFN-β-inducing ability of LO28 by comparing it with that of strain EGD, a low-IFN-β-inducing strain. It was found that LO28 secretes a large amount of IFN-β-inducing factor, which turned out to be cyclic di-AMP. The secretion of cyclic di-AMP was dependent on MdrT, a multidrug resistance transporter, and LO28 exhibited a very high level of mdrT expression. The introduction of a null mutation into mdrT abolished the ability of LO28 to induce IFN-β production. Examination of genes responsible for the regulation of mdrT expression

SUBMITTER: Yamamoto T 

PROVIDER: S-EPMC3416470 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature