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.
