Overcoming Symmetry Mismatch in Vaccine Nanoassembly through Spontaneous Amidation

Abstract

Matching of symmetry at interfaces is afundamental obstacle in molecular assembly.Virus-like particles (VLPs) are important vaccine platforms against pathogenic threats,i ncluding Covid-19. However,s ymmetry mismatchc an prohibit vaccine nanoassembly.W ee stablished an approach for coupling VLPs to diverse antigen symmetries.S pyCatcher003 enabled efficient VLP conjugation and extreme thermal resilience.M any people had pre-existing antibodies to Spy-Tag:SpyCatcher but less to the 003 variants.W ec oupled the computer-designed VLP not only to monomers (SARS-CoV-2) but also to cyclic dimers (Newcastle disease,L yme disease), trimers (influenza hemagglutinins), and tetramers (influenza neuraminidases). Even an antigen with dihedral symmetry could be displayed. Fort he global challenge of influenza, SpyTag-mediated display of trimer and tetramer antigens strongly induced neutralizing antibodies.S pyCatcher003 conjugation enables nanodisplayo fd iverse symmetries towards generation of potent vaccines.

Mosaic nanoparticles elicit cross-reactive immune responses to zoonotic coronaviruses in mice

“…Although promising for protection against SARS-CoV-2, coronavirus reservoirs in bats suggest future cross-species transmission ( 6, 7, 35 ), necessitating a vaccine that protects against emerging coronaviruses as well as SARS-CoV-2. Here we prepared SpyCatcher003-mi3 nanoparticles ( 31 , 36 ) simultaneously displaying SpyTagged RBDs from human and animal coronaviruses to evaluate whether mosaic particles can elicit cross-reactive antibody responses, as previously demonstrated for influenza head domain mosaic particles ( 37 ). We show that mice immunized with homotypic or mosaic nanoparticles produced broad binding and neutralizing responses, in contrast to plasma antibodies elicited in humans by SARS-CoV-2 infection.…”

“…SpyTag003-RBDs were coupled to SpyCatcher003-mi3 (60 potential conjugation sites) ( 36 , 43 ) to make homotypic and mosaic nanoparticles (Fig 2A). Particles were purified by size exclusion chromatography (SEC) and analyzed by SDS-PAGE, revealing monodisperse SEC profiles and nearly 100% conjugation (Fig.…”

A COVID-19 vaccine candidate using SpyCatcher multimerization of the SARS-CoV-2 spike protein receptor-binding domain induces potent neutralising antibody responses

“…To improve immunogenicity, we conjugated the RBD onto a VLP. VLP display of protein antigen has been shown to further enhance immunogenicity by facilitating antigen drainage to lymph nodes, enhancing uptake by antigen-presenting cells and increasing B cell receptor crosslinking 10,18 . Moreover, we recently showed that influenza antigens (haemagglutinin (HA) or neuraminidase (NA)) displayed on VLPs (the same VLP used in this study) were highly immunogenic at a low dose (0.1 µg) in mice 18 .…”

“…In the present study, we used the SpyTag/SpyCatcher technology for the assembly of SARS-CoV-2 RBD on a protein nanoparticle platform, SpyCatcher003-mi3 18 . The VLP platform, based on an engineered aldolase from thermophilic bacteria, spontaneously assembles into a hollow 36-nanometre dodecahedral cage with 60 subunits 19,20 .…”

“…SpyCatcher003 is a variant of SpyCatcher which was engineered for accelerated reaction with SpyTag 21 . The SpyCatcher003-mi3 VLP can be expressed to high yields (100 mg/L of culture media) in E. coli and purified using scalable ammonium sulfate precipitation followed by size exclusion chromatography 18 . Furthermore, the VLP platform has high thermal stability and good colloidal properties 18 .…”