A platform incorporating trimeric antigens into self-assembling nanoparticles reveals SARS-CoV-2-spike nanoparticles to elicit substantially higher neutralizing responses than spike alone

Sci Rep. 2020 Oct 23;10(1):18149. doi: 10.1038/s41598-020-74949-2.


Antigens displayed on self-assembling nanoparticles can stimulate strong immune responses and have been playing an increasingly prominent role in structure-based vaccines. However, the development of such immunogens is often complicated by inefficiencies in their production. To alleviate this issue, we developed a plug-and-play platform using the spontaneous isopeptide-bond formation of the SpyTag:SpyCatcher system to display trimeric antigens on self-assembling nanoparticles, including the 60-subunit Aquifex aeolicus lumazine synthase (LuS) and the 24-subunit Helicobacter pylori ferritin. LuS and ferritin coupled to SpyTag expressed well in a mammalian expression system when an N-linked glycan was added to the nanoparticle surface. The respiratory syncytial virus fusion (F) glycoprotein trimer-stabilized in the prefusion conformation and fused with SpyCatcher-could be efficiently conjugated to LuS-SpyTag or ferritin-SpyTag, enabling multivalent display of F trimers with prefusion antigenicity. Similarly, F-glycoprotein trimers from human parainfluenza virus-type 3 and spike-glycoprotein trimers from SARS-CoV-2 could be displayed on LuS nanoparticles with decent yield and antigenicity. Notably, murine vaccination with 0.08 µg of SARS-CoV-2 spike-LuS nanoparticle elicited similar neutralizing responses as 2.0 µg of spike, which was ~ 25-fold higher on a weight-per-weight basis. The versatile platform described here thus allows for multivalent plug-and-play presentation on self-assembling nanoparticles of trimeric viral antigens, with SARS-CoV-2 spike-LuS nanoparticles inducing particularly potent neutralizing responses.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Antibodies, Neutralizing / immunology
  • Antigens / genetics
  • Antigens / immunology*
  • Antigens / metabolism
  • Aquifex
  • Bacteria / enzymology
  • Bacterial Proteins / genetics
  • Betacoronavirus / isolation & purification
  • Betacoronavirus / metabolism*
  • COVID-19
  • Coronavirus Infections
  • Ferritins / genetics
  • Helicobacter pylori / metabolism
  • Humans
  • Mice
  • Multienzyme Complexes / genetics
  • Nanoparticles / chemistry*
  • Neutralization Tests
  • Pandemics
  • Pneumonia, Viral
  • Protein Multimerization
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / immunology
  • SARS-CoV-2
  • Spike Glycoprotein, Coronavirus / genetics
  • Spike Glycoprotein, Coronavirus / immunology*
  • Spike Glycoprotein, Coronavirus / metabolism
  • Surface Properties


  • Antibodies, Neutralizing
  • Antigens
  • Bacterial Proteins
  • Multienzyme Complexes
  • Recombinant Proteins
  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2
  • 6,7-dimethyl-8-ribityllumazine synthase
  • Ferritins

Supplementary concepts

  • Aquifex aeolicus