Designed proteins assemble antibodies into modular nanocages

Abstract

Antibodies are widely used in biology and medicine, and there has been considerable interest in multivalent antibody formats that increase binding avidity and enhance signaling. However, general approaches are lacking for forming precisely oriented antibody assemblies with controlled valency. For my doctoral thesis, I computationally designed two-component nanocages that overcome this limitation by uniting form and function. One nanocage component is any suitable antibody or Fc-fusion, and the second is a designed Fc-binding homo-oligomer that drives nanocage assembly. Structures of 8 antibody nanocages match the corresponding computational models, spanning dihedral, tetrahedral, octahedral, and icosahedral architectures with 2, 6, 12, and 30 antibodies per nanocage. Antibody nanocages targeting cell-surface receptors enhance signaling compared to free antibodies or Fc-fusions in DR5-mediated apoptosis, Tie2-mediated angiogenesis, CD40 activation, and T cell proliferation; nanocage assembly also increases SARS-CoV-2 pseudovirus neutralization by ⍺-SARS-CoV-2 monoclonal antibodies and Fc-ACE2 fusion proteins.