Project description
Molecular mechanisms of cell self-defence
Many pathogens have the ability to escape the immune system by invading the host cells and hiding inside phagosomes whose membrane prevents pathogen recognition and elimination. Cell-autonomous immunity represents the part of the cell self-defence system that fights off such pathogens. This immune response mobilises the guanylate-binding proteins that form dynamic supramolecular complexes promoting lysis of phagosomes and elimination of pathogens. The goal of the EU-funded PHAGOSCOPY project is to study molecular mechanisms of this immune response, and to obtain detailed information about the composition of the guanylate-binding protein complex and its rearrangements leading to rupture of the phagosome membrane. The research will employ a novel approach for integrative imaging involving cryo-electron microscopy and fluorescence microscopy in combination with a unique native phagosome ex vivo reconstitution system.
Objective
Our immune system provides a formidable barrier to the many microbial pathogens that we encounter every day. Yet, many pathogens have the ability to avert this barrier by invading the host cell and seeking shelter inside a phagosome whose membrane physically prevents the pathogen from being recognized and eliminated. Cell-autonomous immunity is a part of the innate immune system that fights off such pathogens. Among the antimicrobial effectors mobilized by this immune response are the Guanylate-Binding Proteins (GBPs). GBPs form dynamic supramolecular assemblies that promote lysis of phagosomes and, thus, killing of pathogens. Despite their central importance, we know very little about the molecular mechanisms of GBPs. Two fundamental questions are: (1) What is the structure and composition of GBP assemblies on membranes?, and (2) Once assembled, how do the GBPs structurally rearrange to reshape and rupture the phagosome's membrane? These questions remain unanswered because structural biology has been lacking methods for determining dynamically changing structures of proteins that are assembled in complex environments such as phagosomes. Here, I propose to take a two-pronged approach to address these questions: first, I will use cryo-EM and (single-molecule) fluorescence microscopy to elucidate the interactions and conformational changes involved in GBP oligomerization on model membranes. Second, I will visualize this pathway on native phagosomes using a recently developed ex vivo reconstitution system unique to my laboratory. By determining how GBP assemblies form on phagosome membranes, how they reshape the membrane so that it ruptures, and how these processes can be regulated and inhibited, I will derive a mechanistic model of a key effector function that cells employ to combat disease-causing pathogens. More broadly, my study will establish a novel approach for integrative imaging that will be applicable to a wide range of dynamic molecular assemblies in cells.
Keywords
Project’s keywords as indicated by the project coordinator. Not to be confused with the EuroSciVoc taxonomy (Fields of science)
Project’s keywords as indicated by the project coordinator. Not to be confused with the EuroSciVoc taxonomy (Fields of science)
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
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H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC)
MAIN PROGRAMME
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Topic(s)
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Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
ERC-STG - Starting Grant
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Call for proposal
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Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
(opens in new window) ERC-2019-STG
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Net EU financial contribution. The sum of money that the participant receives, deducted by the EU contribution to its linked third party. It considers the distribution of the EU financial contribution between direct beneficiaries of the project and other types of participants, like third-party participants.
2628 CN DELFT
Netherlands
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