Tiny Clusters for Big Impact in T Cell Activation.

The regulation of T cell activation via engineered arrays holds significant biomedical potential. While average antibody density is known to influence T cell activation, antibody clustering has shown limited benefits. This study challenges this perspective through combined experimental and theoretical approaches. By employing nanolithographically patterned arrays, we show that full T cell activation is achievable with a small number of densely packed antibody clusters─even at average densities where homogeneous or sparsely clustered distributions are insufficient for full activation. These results align with the membrane-fluctuation model that considers cooperative binding and mechanical feedback. Our findings highlight the importance of the spatial organization of activating ligands and provide a framework for designing improved T cell activation platforms for immunotherapy.