Janus nanoparticles for T cell activation: clustering ligands to enhance stimulation

Abstract

The in vitro activation of T cells by synthetic particles is a promising technique for adoptive cancer immunotherapy. While it is known that cell-surface receptors form clusters during T cell activation, the use of clustered ligands on synthetic particles to modulate T cell response is a largely unexplored concept. Building upon our previous finding that T cells respond differently to various micro-sized patterns of ligands, we here investigate the effect of nano-sized ligand clusters on T cell activation. Two-faced Janus nanoparticles were fabricated to display ligands of different functions in spatially segregated clusters on single nanoparticles. Going beyond our earlier qualitative study, here we precisely quantified and controlled the surface density and the total amount of ligands on single nanoparticles. We show that nanoparticles with clustered ligands activate T cells to a greater level than ones uniformly coated with the same number of ligands. The enhanced effect is due to increased local surface density of ligands. The results demonstrate that the spatial arrangement of ligands on particles influences activation response of T cells and may be used as a new strategy to increase T cell stimulation in the presence of insufficient amount of stimuli. This fundamental study also represents an initial step in using nanoscale Janus particles for manipulating immune cell responses.

Tumor Targeted Nanocarriers for Immunotherapy

“…Regarding the use of antibody-decorated nanoparticles to activate T cells, different parameters such as surface density and spatial arrangement of these antibodies on the nanoparticle, as well as their amount, should be considered. A recent work has concluded that Janus-type nanoparticles with clustered ligands produced a better T cell activation than nanoparticles homogeneously decorated with the same amounts of ligands [85]. This result could be explained by the co-existence of multiple ligand-receptor interactions in the cluster conformation, which enhances the signal transduction in the lymphocyte.…”

Nanoscale Janus Particles with Dual Protein Functionalization

“…At the lower end of the size spectrum, Lee and Yu prepared 500 nm silica Janus particles using a microcontact printing procedure with azide functionalized SiNPs followed by side‐specific antibody attachment via amine‐carboxylate carbodiimide chemistry. The covalently attached antibodies were thereafter shown to selectively target CD3 and CD25 receptors on T‐cells . Tang et al prepared bifunctional 2.0–4.5 µm silica and polystyrene Janus particles using a metal deposition technique followed by the orthogonal approaches of carbodiimide chemistry and biotin–streptavidin binding for protein functionalization at the respective faces.…”

“…The covalently attached antibodies were thereafter shown to selectively target CD3 and CD25 receptors on T-cells. [4] Tang et al prepared bifunctional 2.0-4.5 µm silica and polystyrene Janus particles using a metal deposition technique followed by the orthogonal approaches of carbodiimide chemistry and biotin-streptavidin binding for protein functionalization at the respective faces. [7b] Similarly, Bradley et al presented 850 nm Janus particles with multiple clickable polystyrene and poly(propargyl acrylate) sides using thiol-yne click chemistry for conjugation.…”

“…The concept of Janus particles, which was first introduced by Nobel laureate Pierre de Gennes in his acceptance speech in 1991, is defined by spatially separated surface functionalities on a single nanoparticle with dual faces and thus enables dual functionalization of colloidal particles on separate sides. Biofunctional Janus particles are emerging tools in cell targeting, imaging, manipulation of cell immune response, and are particularly promising for tailoring cell membrane interactions due to their inherent amphiphilicity . For use in applications at the nano–bio interface, Janus nanoparticles need to be functionalized with biological ligands, such as proteins.…”

“…Similarly, the other mentioned papers mostly describe successful preparation of nanoscale Janus particles as proof‐of‐principle for specific applications. [4,8b,13a,b,d,e,21]…”