Role of nanoscale antigen organization on B-cell activation probed using DNA origami

Vaccine efficacy can be increased by arraying immunogens in multivalent form on virus-like nanoparticles to enhance B cell activation. However, the effects of antigen copy number, spacing, and affinity, as well as the dimensionality and rigidity of scaffold presentation on B cell activation remain poorly understood. Here, we displayed the clinical vaccine immunogen eOD-GT8, an engineered outer domain of the HIV-1 glycoprotein-120, on DNA origami nanoparticles to systematically interrogate the impact of these nanoscale parameters on B cell activation in vitro. We found that B cell signalling is maximized by as few as five antigens maximally spaced on the surface of a 40 nm viral-like nanoparticle. Increasing antigen spacing up to ~25–30 nm monotonically increases B cell receptor activation. Moreover, scaffold rigidity is essential for robust B cell triggering. These results reveal molecular vaccine design principles that may be used to drive functional B cell responses.