PEG-based antigen-presenting cell surrogates for immunological applications

T-cell interactions with antigen-presenting cells (APCs) are involved in nearly every immunological response in vivo, and consequently activate multiple signaling pathways that, in concert, initiate, drive, and regulate the body's adaptive and innate immune system responses to foreign pathogens and mutations. Although the fundamental characterization of T cell–APC interactions is a compelling goal, little progress has yet been made, mainly due to its extensive complexity. Therefore, engineering APC surrogates for the controlled manipulation of T cells in vitro has become an important strategy, particularly in medical applications, and can contribute to the understanding of the mechanisms underlying the ability of T cells to perform “intelligent” missions, such as acquiring, processing, and responding to environmental information. This chapter describes recently developed soft/elastic nanopatterned biomimetic systems for immunological applications. Particular attention is devoted to nanopatterned 2D and 3D artificial APC systems based on poly(ethylene glycol) (PEG) materials. These PEG-based APC surrogates allow independent control over material elasticity and the nanoscale distribution of bio-ligands and as a consequence are able to simulate ex vivo signals originating from naturally occurring APCs