Cell‐Sized Lipid Vesicles as Artificial Antigen‐Presenting Cells for Antigen‐Specific T Cell Activation

Abstract In this study, efficient T cell activation is demonstrated using cell‐sized artificial antigen‐presenting cells (aAPCs) with protein‐conjugated bilayer lipid membranes that mimic biological cell membranes. The highly uniform aAPCs are generated by a facile method based on standard droplet microfluidic devices. These aAPCs are able to activate the T cells in peripheral blood mononuclear cells, showing a 28‐fold increase in interferon gamma (IFN γ ) secretion, a 233‐fold increase in antigen‐specific CD8 T cells expansion, and a 16‐fold increase of CD4 T cell expansion. The aAPCs do not require repetitive boosting or additional stimulants and can function at a relatively low aAPC‐to‐T cell ratio (1:17). The research presents strong evidence that the surface fluidity and size of the aAPCs are critical to the effective formation of immune synapses essential for T cell activation. The findings demonstrate that the microfluidic‐generated aAPCs can be instrumental in investigating the physiological conditions and mechanisms for T cell activation. Finally, this method demonstrates the feasibility of customizable aAPCs for a cost‐effective off‐the‐shelf approach to immunotherapy.