Single-component multilayered self-assembling protein nanoparticles presenting glycan-trimmed uncleaved prefusion optimized envelope trimers as HIV-1 vaccine candidates

Abstract

Uncleaved prefusion-optimized (UFO) design can stabilize diverse HIV-1 envelope glycoproteins (Envs). Single-component, self-assembling protein nanoparticles (1c-SApNP) can display 8 or 20 native-like Env trimers as vaccine candidates. We characterize the biophysical, structural, and antigenic properties of 1c-SApNPs that present the BG505 UFO trimer with wildtype and modified glycans. For 1c-SApNPs, glycan trimming improves recognition of the CD4 binding site without affecting broadly neutralizing antibodies (bNAbs) to major glycan epitopes. In mice, rabbits, and nonhuman primates, glycan trimming increases the frequency of vaccine responders (FVR) and steers antibody responses away from immunodominant glycan holes and glycan patches. The mechanism of vaccine-induced immunity is examined in mice. Compared with the UFO trimer, the multilayered E2p and I3-01v9 1c-SApNPs show 420 times longer retention in lymph node follicles, 20-32 times greater presentation on follicular dendritic cell dendrites, and up-to-4 times stronger germinal center reactions. These findings can inform future HIV-1 vaccine development.

Single-Component Multilayered Self-Assembling Protein Nanoparticles Displaying Extracellular Domains of Matrix Protein 2 as a Pan-influenza A Vaccine

“…Additionally, the M2ex3 FR and I3-01v9a SApNPs also showed 45–86 times greater accumulation compared with the M2ex3 trimer at 1 week (Figure F). These results are consistent with our previous findings, ,, in which small particles (<15 nm) were cleared from lymph node follicles within 48 h, whereas large particles (30–100 nm) remained for weeks. Importantly, M2ex3 I3-01v9a and BG505 Env I3-01v9 SApNPs showed significantly longer follicular retention than the SARS-CoV-2 spike-presenting I3-01v9 SApNP (∼8 weeks vs ∼2 weeks), , suggesting a correlation between SApNP retention and antigen thermostability (a T m value of 65 °C or greater for M2ex3 and BG505 Env vs 48 °C for SARS-CoV-2 spike).…”

“…In summary, hM2e can be successfully displayed on all three SApNPs, consistent with our previous studies where stabilized HIV-1, ,, HCV, EBOV, and SARS-CoV-1/2 , antigens were displayed on the surface of SApNPs. Extensive biochemical, biophysical, structural, and antigenic characterizations provided detailed in vitro profiles of hM2e-presenting SApNPs, thus allowing evaluation of these vaccine immunogens in vivo.…”

“…Then, a protein structure sampling program, CONCOORD, was used to generate 1,000 slightly perturbed conformations for the modified I3-01v9 subunit. Next, an ensemble-based protein design program that was previously used to optimize HIV-1 Env trimers and HCV E2 cores was employed to predict the sequence for the first 9 residues of the 11-residue segment using C α and C β -based RAPDF scoring functions . The final design, termed I3-01v9a, was determined by combining results from predictions using both scoring functions (Figure S1).…”

Prospects for developing an Hepatitis C virus E1E2‐based nanoparticle vaccine

“…The authors accomplished this in one of two ways, either through an extended dosing schedule or via using different NP versions of HIV env. Similar results also were observed using HIV env in a different study by Zhang et al 133 The authors in the Zhang et al showed that two different NP versions of HIV env were retained for 420 times longer in FDCs and thereby elicited much stronger germinal centre reactions, a key component of protective immunity. The fact that two separate groups showed that protein-based NPs facilitate targeting to FDCs where antigen retention is enhanced and leads to robust B cell recognition of the intact antigen is an intriguing finding that highlights the potential of protein NP-based vaccines as a platform to increase the potency of subunit vaccines.…”

“…A third type of particulate assembly that has been developed more recently for use in vaccines is protein-based NPs. NP platforms for the multivalent display of vaccine antigens have proven effective in boosting immunogenicity for antigens such as Ebola GP, 130 HIV env, [131][132][133] SARS CoV-2 spike, 134 RSV F, 135 and influenza haemagglutinin. 136…”