Microglia response to Listeria monocytogenes infection

Elisabet Frande-Cabanes, Ricardo Calderon Gonzalez, Hector Teran-Navarro, Carmen Alvarez-Dominguez

Research output: Contribution to conferencePosterpeer-review

Abstract

Listeria monocytogenes is a human pathogen and an intracellular bacterium with tropism for the nervous tissue. Microglia are innate immune cells of the brain that play a central role in cerebral listeriosis.

Listeriosis causes several brain damages as meningitis, encephalitis or brain abscesses.

Our hypothesis implies that microglia control Listeria monocytogenes infection differently than macrophages. Infection of primary microglial cultures and murine cell lines with this human pathogen resulted in a dual function of the two gene expression programmes involved in early and late immune responses in macrophages.

Whereas the bacterial gene hly seems responsible for both transcriptional programmes in macrophages, Listeria monocytogenes induces in microglia only the tumor necrosis factor (TNF)-regulated transcriptional programme. Listeria also represses in microglia the late immune response gathered in two clusters, microbial degradation, and interferon (IFN)-inducible genes.

The bacterial gene actA was required in microglia to induce TNF-regulated responses and to repress the late response. Isolation of microglial phagosomes revealed a phagosomal environment unable to destroy Listeria. Microglial phagosomes were also defective in several signalling and trafficking components reported as relevant for Listeria innate immune responses. This transcriptional strategy in microglia induced high levels of TNF-α and monocyte chemotactic protein1 and low production of other neurotoxic compounds such as nitric oxide, hydrogen peroxide, and Type I IFNs. These cytokines and toxic microglial products are also released by primary microglia, and this cytokine and chemokine cocktail display a low potential to trigger neuronal apoptosis.

This overall bacterial strategy strongly suggests that microglia limits Listeria inflammation pattern exclusively through TNF-mediated responses to preserve brain integrity.
Original languageEnglish
Publication statusPublished - 15 Jun 2016
Externally publishedYes
EventEMBO Conference: Problems of Listeriosis ISOPOL XIX - Institut Pasteur, Paris, France
Duration: 14 Jun 201617 Jun 2016
Conference number: XIX
https://research.pasteur.fr/en/event/isopol-xix/

Conference

ConferenceEMBO Conference: Problems of Listeriosis ISOPOL XIX
Abbreviated titleISOPOL
CountryFrance
CityParis
Period14/06/201617/06/2016
Internet address

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