Nanoscale
organization is crucial to stimulating an immune response.
Using self-assembling proteins as multimerization platforms provides
a safe and immunogenic system to vaccinate against otherwise weakly
immunogenic antigens. Such multimerization platforms are generally
based on icosahedral viruses and have led to vaccines given to millions
of people. It is unclear whether synthetic protein nanoassemblies
would show similar potency. Here we take the computationally designed
porous dodecahedral i301 60-mer and rationally engineer this particle,
giving a mutated i301 (mi3) with improved particle uniformity and
stability. To simplify the conjugation of this nanoparticle, we employ
a SpyCatcher fusion of mi3, such that an antigen of interest linked
to the SpyTag peptide can spontaneously couple through isopeptide
bond formation (Plug-and-Display). SpyCatcher-mi3 expressed solubly
to high yields in Escherichia coli, giving more than
10-fold greater yield than a comparable phage-derived icosahedral
nanoparticle, SpyCatcher-AP205. SpyCatcher-mi3 nanoparticles showed
high stability to temperature, freeze–thaw, lyophilization,
and storage over time. We demonstrate approximately 95% efficiency
coupling to different transmission-blocking and blood-stage malaria
antigens. Plasmodium falciparum CyRPA was conjugated
to SpyCatcher-mi3 nanoparticles and elicited a high avidity antibody
response, comparable to phage-derived virus-like particles despite
their higher valency and RNA cargo. The simple production, precise
derivatization, and exceptional ruggedness of this nanoscaffold should
facilitate broad application for nanobiotechnology and vaccine development.