minimal-phagocyte · Reconstitution of the basic molecular mechanism of phagocytosis – a bottom-up synthetic biology approach
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-09-01 → 2018-08-31
- EU contribution
- €159,461
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Reconstitution of the basic molecular mechanism of phagocytosis – a bottom-up synthetic biology approach
Phagocytosis is the process by which a cell engulfs another cell or particle greater than 0.5 mm by invagination of the cell membrane around the object, and subsequent abscission of the membrane-coated object to form an intracellular, membrane-bound organelle. Phagocytosis is of fundamental importance to both single-cell organisms (for feeding), and multicellular organisms (for defending against pathogens and tissue re-modelling). The key aim of this action was to define the “minimal phagocyte” – i.e. the minimal number of components that enable a cell to carry out this process of phagocytosis –– to allow us (1) to fully capture its essential features, (2) to recreate it in vitro, and (3) to modulate it. Beyond increasing our knowledge about one of the most basic features of living cells, this project was aimed at generating knowledge with the potential to aid the design of novel biotechnological applications, such as improved drug delivery by preventing or promoting phagocytic uptake. In summary, this project proposed to construct this “minimal phagocyte” by building a bio-inspired in vitro system capable of phagocytosis from the bottom up by reconstituting a minimal, dynamic actin cytoskeleton in receptor-carrying, cell-sized lipid vesicles to create an artificial phagocyte (i.e. a vesicle capable of taking up a particle). While even after the conclusion of the action, this goal – a complete minimal model system for phagocytosis – remains unachieved, key technologies were developed that not only will allow constructing of this minimal phagocyte in the years to come, but that will also benefit other, related research endeavours.
Data: CORDIS, © European Union
Project objective
The ability of cells to engulf large objects, such as invading microorganisms or apoptotic cells, is crucial to innate immunity and tissue remodelling. The molecular basis of this process - phagocytosis - is complex, involving numerous receptors and signalling pathways. Nevertheless, the biophysical process is always the same: the cell membrane deforms and reshapes to wrap around the particle, and upon closure and abscission of the resultant cup, the particle is internalised. Although the key molecular players in individual phagocytic pathways have been identified, we still know very little about the basic biophysics common to all phagocytic pathways. I propose to fill this gap in our knowledge by creating a “minimal phagocyte”: I aim to reconstitute a minimal, dynamic actin cytoskeleton and artificial phagocytic receptors in giant unilamellar vesicles (GUVs), thereby identifying the molecular components that are not only necessary but also sufficient for phagocytosis. Using synthetic biology to build a bottom-up model of phagocytosis should answer many open questions, including: are spatial cues resulting from particle binding required for membrane wrapping around the particle? Is directed initiation of actin polymerisation sufficient to render GUVs capable of phagocytosis? What is the role of the membrane-supporting actin cortex and how does the affinity of the receptors affect the engulfment process? Beyond phagocytosis, the minimal-model approach I propose will also be useful to study other cellular functions requiring actin-driven membrane reorganisation, such as cell mobility. In line with the objectives set by ERA-NET ERASynBio and the Horizon 2020 work programme (which identified synthetic biology as one of the “cutting-edge biotechnologies as future innovation drivers”), the creation of “protocells” will not only enhance our understanding of biology, but ultimately also result in novel biotechnological applications, such as improved drug delivery systems.
Original text from CORDIS.
Participants
- MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV · MUNCHENCoordinatorGermany
Links
Data: CORDIS, © European Union