Single-component multilayered self-assembling nanoparticles presenting rationally designed glycoprotein trimers as Ebola virus vaccines

Abstract

Ebola virus (EBOV) glycoprotein (GP) can be recognized by neutralizing antibodies (NAbs) and is the main target for vaccine design. Here, we first investigate the contribution of the stalk and heptad repeat 1-C (HR1C) regions to GP metastability. Specific stalk and HR1C modifications in a mucin-deleted form (GPΔmuc) increase trimer yield, whereas alterations of HR1C exert a more complex effect on thermostability. Crystal structures are determined to validate two rationally designed GPΔmuc trimers in their unliganded state. We then display a modified GPΔmuc trimer on reengineered protein nanoparticles that encapsulate a layer of locking domains (LD) and a cluster of helper T-cell epitopes. In mice and rabbits, GP trimers and nanoparticles elicit cross-ebolavirus NAbs, as well as non-NAbs that enhance pseudovirus infection. Repertoire sequencing reveals quantitative profiles of vaccine-induced B-cell responses. This study demonstrates a promising vaccine strategy for filoviruses, such as EBOV, based on GP stabilization and nanoparticle display.

Mechanism of a COVID-19 nanoparticle vaccine candidate that elicits a broadly neutralizing antibody response to SARS-CoV-2 variants

“…Similar immunization protocols were reported in our previous vaccine studies ( 41 , 86 , 87 ). Briefly, the Institutional Animal Care and Use Committee (IACUC) guidelines were followed for all of the animal studies.…”

“…S10F, right two). In our previous studies ( 86 , 87 ), a similar approach was applied to assess hepatitis C virus (HCV) and Ebola virus (EBOV) vaccine-induced B cell responses in the spleen, a major lymphoid organ ( 88 ), after mice received four intraperitoneal injections. We observed distinct B cell profiles associated with the viral antigen and NP platform ( 86 , 87 ).…”

“…In our previous studies ( 86 , 87 ), a similar approach was applied to assess hepatitis C virus (HCV) and Ebola virus (EBOV) vaccine-induced B cell responses in the spleen, a major lymphoid organ ( 88 ), after mice received four intraperitoneal injections. We observed distinct B cell profiles associated with the viral antigen and NP platform ( 86 , 87 ). Here, the lymph node B cell profiles appeared to be rather different, revealing the complex inner workings of another primary site for vaccine-induced immunity.…”

“…Briefly, HC and KC libraries from the same mouse were quantitated using a Qubit 2.0 Fluorometer with the Qubit dsDNA HS Assay Kit and then mixed at a 3:1 ratio before being pooled with antibody libraries of other mice at an equal ratio for sequencing. Template preparation and (Ion 530) chip loading were performed on Ion Chef using the Ion 520/530 Ext Kit, followed by sequencing on the Ion S5 system with default settings ( 86 ). The mouse antibodyomics pipeline ( 69 ) was used to process raw NGS data; to derive quantitative profiles for germline gene frequency, the degree of SHM, and CDR3 loop length distribution; and to generate 2D divergence/identity plots to visualize mAbs in their respective repertoires ( 86 ).…”

Platforms for Production of Protein-Based Vaccines: From Classical to Next-Generation Strategies

“…The HEK293 cell line is also a platform of interest for production of recombinant viral vectors and vaccines at the industrial scale, because the cells are easy to grow in suspension and can be adapted to serum-free medium. Current developments of human vaccines using HEK293 cells include the expression of glycoproteins for the treatment of infectious diseases, such as rabies [209] or Ebola virus [210]. A recent study of a vaccine candidate against Trypanosoma vivax showed that an invariant antigen expressed in HEK293 cells was able to induce protective immunity in mice [211], showing promising results as a vaccine candidate.…”