Analysis of transcriptional signatures in response to Listeria monocytogenes infection reveals temporal and strain dependent changes in interferon signalling

Listeriosis is an infectious disease caused by the intracellular bacterium Listeria monocytogenes. To control the infection effectively, the host immune response is directed by intercellular signalling molecules called cytokines that are produced by immune cells following sensing of the bacteria. In this study we used gene expression analysis to examine complex immune signalling networks in the blood and tissues of mice infected with L. monocytogenes. We show that a large set of genes are perturbed in both blood and tissue upon infection and that the transcriptional responses in both are enriched for pathways of the immune response. From these data we also observe an important signalling network emerge from a group of cytokines called interferons (IFNs). Previous findings suggest that different IFN family members can determine the balance between successful and impaired immune responses to L. monocytogenes and several other bacterial infections. Using mice deficient for the detrimental type I IFN signalling pathway we show that IFN-inducible genes are differentially regulated at different times upon infection but also present at much lower levels in uninfected mice highlighting how dysregulation of this network in the steady state may determine the outcome of this bacterial infection.

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Pitt JM, Blankley S, Potempa K, Graham CM, Moreira-Teixeira L, McNab FW, Howes A, Stavropoulos E, Pascual V, Banchereau J, Chaussabel D, O'Garra A