Adaptation of Neisseria meningitidis to the microenvironment induced upon vascular colonization

Adaptation of Neisseria meningitidis to the microenvironment induced upon vascular colonization

By In Aiv Internship On June 7, 2018

Internship title: Adaptation of Neisseria meningitidis to the microenvironment induced upon vascular colonization

Name: Pathogenesis of Vascular Infections” Unit
Affiliation: Institut Pasteur, “Cell Biology and Infection” Department
Address: 28 rue du Docteur Roux 75015 Paris

LAB Director
Name: Guillaume Duménil
Phone number: 0144389383

Name: Dorian Obino
Phone number: 0145688361

Subject Keywords: Neisseria meningitidis, metabolism, host/pathogen interaction, microenvironment, cell proliferation

Tools and methodologies: Live-cell Microscopy, immunofluorescence, micro-fabrication, image analysis, cell culture

Summary of lab’s interests: Neisseria meningitidis (Nm) is a pathogenic bacterium responsible for meningitis and sepsis in humans. During infection, bacteria adhere to the endothelium and proliferate inside blood vessels in the form of multicellular aggregates, leading to vascular colonization and damage. Upon adhesion, the bacterial colony induces plasma membrane remodeling of the host cell to resist to the mechanical stress induced by the blood flow. All these processes rely on type IV pili, dynamic filamentous organelles protruding out of the bacterial body. The lab integrates a multidisciplinary approach combining microbiology with cell biology, vascular biology, chemistry and physics to study the pathogenesis of Nm infection.

Project summary: We hypothesize that vascular colonization by Nm may induce drastic changes within the local vessel microenvironment, potentially impacting both bacteria physiology and the surrounding endothelial cells. To tackle this question, we first propose to combine live imaging and the use of microfabricated devices to:
i) assess the state of bacteria within the aggregate (surface levels of pili, stationary vs proliferative state, live vs dead…) at the single cell-level,
ii) define the local microenvironment (nutrient availability, metabolite release…) induced upon vessel occlusion and
iii) determine the impact of this new microenvironment on the physiology of both bacteria and endothelial cells (activation of specific signaling pathways notably).
The combined use of cell lines expressing fluorescently tagged proteins, various mutant or genetically-engineered Nm strains and drugs will allow us to quantitatively define the role of the microenvironment during Nm infection.
These results will be part of a global project focusing on the cell biology aspects of host/pathogen interaction between Nm and the human endothelium.

Interdisciplinary aspect of the project: To achieve this goal, the project integrates a multidisciplinary approach by combining classical cell biology techniques, live cell microscopy, microfabrication and image analysis. The student will take advantage of the lab wide expertise to learn how to manipulate pathogenic bacteria, define optimal and robust experimental conditions to study in vitro infection by Nm and write simple scripts (Matlab, Fiji etc.) for data analysis. All these quantitative tools will be of great help also in other pathogenic contexts, opening the possibility to collaborate with other laboratories within the Institute or abroad.