Bacterially expressed HIV-1 gp120 outer-domain fragment immunogens with improved stability and affinity for CD4-binding site neutralizing antibodies.
J Biol Chem
; 293(39): 15002-15020, 2018 09 28.
Article
em En
| MEDLINE
| ID: mdl-30093409
ABSTRACT
Protein minimization is an attractive approach for designing vaccines against rapidly evolving pathogens such as human immunodeficiency virus, type 1 (HIV-1), because it can help in focusing the immune response toward conserved conformational epitopes present on complex targets. The outer domain (OD) of HIV-1 gp120 contains epitopes for a large number of neutralizing antibodies and therefore is a primary target for structure-based vaccine design. We have previously designed a bacterially expressed outer-domain immunogen (ODEC) that bound CD4-binding site (CD4bs) ligands with 3-12 µm affinity and elicited a modest neutralizing antibody response in rabbits. In this study, we have optimized ODEC using consensus sequence design, cyclic permutation, and structure-guided mutations to generate a number of variants with improved yields, biophysical properties, stabilities, and affinities (KD of 10-50 nm) for various CD4bs targeting broadly neutralizing antibodies, including the germline-reverted version of the broadly neutralizing antibody VRC01. In contrast to ODEC, the optimized immunogens elicited high anti-gp120 titers in rabbits as early as 6 weeks post-immunization, before any gp120 boost was given. Following two gp120 boosts, sera collected at week 22 showed cross-clade neutralization of tier 1 HIV-1 viruses. Using a number of different prime/boost combinations, we have identified a cyclically permuted OD fragment as the best priming immunogen, and a trimeric, cyclically permuted gp120 as the most suitable boosting molecule among the tested immunogens. This study also provides insights into some of the biophysical correlates of improved immunogenicity.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Antígenos CD4
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Proteína gp120 do Envelope de HIV
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Infecções por HIV
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HIV-1
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Vacinas contra a AIDS
Limite:
Animals
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Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2018
Tipo de documento:
Article