Spatial organization of FcγR and TLR2/1 on phagosome membranes differentially regulates their synergistic and inhibitory receptor crosstalk

A Spatially Programmable DNA Nanorobot Arm to Modulate Anisotropic Gold Nanoparticle Assembly by Enzymatic Excision

Programmable assembly of gold nanoparticle superstructures with precise spatial arrangement has drawn much attention for their unique characteristics in plasmonics and biomedicine. Bio-inspired methods have already provided programmable, molecular approaches to direct AuNP assemblies using biopolymers. The existing methods, however, predominantly use DNA as scaffolds to directly guide the AuNP interactions to produce intended superstructures. New paradigms for regulating AuNP assembly will greatly enrich the toolbox for DNA-directed AuNP manipulation and fabrication. Here, we developed a strategy of using a spatially programmable enzymatic nanorobot arm to modulate anisotropic DNA surface modifications and assembly of AuNPs. Through spatial controls of the proximity of the reactants, the locations of the modifications were precisely regulated. We demonstrated the control of the modifications on a single 15 nm AuNP, as well as on a rectangular DNA origami platform, to direct unique anisotropic AuNP assemblies. This method adds an alternative enzymatic manipulation to DNA-directed AuNP superstructure assembly.

Immobile ligands enhance FcγR-TLR2/1 crosstalk by promoting interface overlap of receptor clusters

Innate immune cells detect pathogens through simultaneous stimulation of multiple receptors, but how cells use the receptor crosstalk to elicit context-appropriate responses is unclear. Here, we reveal that the inflammatory response of macrophages from FcγR-TLR2/1 crosstalk inversely depends on the ligand mobility within a model pathogen membrane. The mechanism is that FcγR and TLR2/1 form separate nanoclusters that interact at their interfaces during crosstalk. Less mobile ligands induce stronger interactions and more overlap between the receptor nanoclusters, leading to enhanced signaling. Different from the prevailing view that immune receptors colocalize to synergize their signaling, our results show that FcγR-TLR2/1 crosstalk occurs through interface interactions between non-colocalizing receptor nanoclusters, which are modulated by ligand mobility. This suggests a mechanism by which innate immune cells could use physical properties of ligands to fine-tune host responses.