Programmable Immunostimulation with Structured DNA Nanoparticles

Compositions containing a nucleic acid nanostructure having a desired geometric shape and immunostimulatory agent(s) bound to its surface are provided. The nanostructures can be, for example, in the form of a 6-helix bundle, or icosahedron, or a pentagonal bipyramid. The nanostructure design allows for control of the relative position and/or stoichiometry of the immunostimulatory agent(s) bound to its surface. The immunostimulatory agent(s) displayed on the nanostructure surface are arranged with the preferred number, spacing, and 3D organization to elicit a robust immune response. The displayed antigen can be a TLR agonist, such as a TLR9 agonist. The immunostimulatory compositions may thus be useful as immunogens, vaccines, adjuvants, and the like. Methods of inducing immune responses, and for targeted induction of TLR activation are also provided.