Live rubella vectors can express native HIV envelope glycoproteins targeted by broadly neutralizing antibodies and prime the immune response to an envelope protein boost

AbstractThe occurrence of oligomannose-specific broadly neutralizing antibodies (bnAbs) has spurred efforts to develop immunogens that can elicit similar antibodies. Here, we report on the antigenicity and immunogenicity of a CRM197-conjugate of a previously reported oligomannose mimetic. Oligomannose-specific bnAbs that are less dependent on interactions with the HIV envelope protein sequence showed strong binding to the glycoconjugates, with affinities approximating those reported for their cognate epitope. The glycoconjugate is also recognized by inferred germline precursors of oligomannose-specific bnAbs, albeit with the expected low avidity, supporting its potential as an immunogen. Immunization of human-antibody transgenic mice revealed that only a TLR4-stimulating adjuvant formulation resulted in antibodies able to bind a panel of recombinant HIV trimers. These antibodies bound at relatively modest levels, possibly explaining their inability to neutralize HIV infectivity. Nevertheless, these findings contribute further to understanding conditions for eliciting HIV-cross-reactive oligomannose-specific antibodies and inform on next steps for improving on the elicited response.

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A glycoside analog of mammalian oligomannose formulated with a TLR4-stimulating adjuvant elicits HIV-1 cross-reactive antibodies

10.21203/rs.3.rs-140631/v1 ◽

2021 ◽

Author(s):

Jean-Francois Bruxelle ◽

Tess Kirilenko ◽

Nino Trattnig ◽

Yiqiu Yang ◽

Matteo Cattin ◽

...

Keyword(s):

Transgenic Mice ◽

Envelope Protein ◽

Protein Sequence ◽

Neutralizing Antibodies ◽

Human Antibody ◽

Broadly Neutralizing Antibodies ◽

Specific Antibodies ◽

Strong Binding ◽

Hiv Envelope ◽

Hiv 1

Abstract The occurrence of oligomannose-specific broadly neutralizing antibodies (bnAbs) has spurred efforts to develop immunogens that can elicit similar antibodies. Here, we report on the antigenicity and immunogenicity of a CRM197-conjugate of a previously reported oligomannose mimetic. Oligomannose-specific bnAbs that are less dependent on interactions with the HIV envelope protein sequence showed strong binding to the glycoconjugates, with affinities approximating those reported for their cognate epitope. The glycoconjugate is also recognized by germline precursors of oligomannose-specific bnAbs, albeit with the expected low avidity, supporting its potential as an immunogen. Immunization of human-antibody transgenic mice revealed that only a TLR4-stimulating adjuvant formulation evoked antibodies able to bind a panel of recombinant HIV trimers. These antibodies bound at relatively modest levels, likely explaining their inability to neutralize HIV infectivity. Nevertheless, these findings contribute further to understanding conditions for eliciting HIV-cross-reactive oligomannose-specific antibodies and inform on next steps for improving on the elicited response.

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A glycoside analog of mammalian oligomannose formulated with a TLR4-stimulating adjuvant elicits HIV-1 cross-reactive antibodies

10.21203/rs.3.rs-140631/v2 ◽

2021 ◽

Author(s):

Jean-Francois Bruxelle ◽

Tess Kirilenko ◽

Nino Trattnig ◽

Yiqiu Yang ◽

Matteo Cattin ◽

...

Keyword(s):

Transgenic Mice ◽

Envelope Protein ◽

Protein Sequence ◽

Neutralizing Antibodies ◽

Human Antibody ◽

Broadly Neutralizing Antibodies ◽

Specific Antibodies ◽

Strong Binding ◽

Hiv Envelope ◽

Hiv 1

Abstract The occurrence of oligomannose-specific broadly neutralizing antibodies (bnAbs) has spurred efforts to develop immunogens that can elicit similar antibodies. Here, we report on the antigenicity and immunogenicity of a CRM197-conjugate of a previously reported oligomannose mimetic. Oligomannose-specific bnAbs that are less dependent on interactions with the HIV envelope protein sequence showed strong binding to the glycoconjugates, with affinities approximating those reported for their cognate epitope. The glycoconjugate is also recognized by germline precursors of oligomannose-specific bnAbs, albeit with the expected low avidity, supporting its potential as an immunogen. Immunization of human-antibody transgenic mice revealed that only a TLR4-stimulating adjuvant formulation evoked antibodies able to bind a panel of recombinant HIV trimers. These antibodies bound at relatively modest levels, likely explaining their inability to neutralize HIV infectivity. Nevertheless, these findings contribute further to understanding conditions for eliciting HIV-cross-reactive oligomannose-specific antibodies and inform on next steps for improving on the elicited response.

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Potent and broadly neutralizing antibodies targeting HIV envelope protein gp120

Future Virology ◽

10.2217/fvl.12.6 ◽

2012 ◽

Vol 7 (3) ◽

pp. 225-227 ◽

Cited By ~ 1

Author(s):

Min Song

Keyword(s):

Envelope Protein ◽

Neutralizing Antibodies ◽

Broadly Neutralizing Antibodies ◽

Protein Gp120 ◽

Hiv Envelope ◽

Envelope Protein Gp120

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Impact of HIV-1 Diversity on Its Sensitivity to Neutralization

Vaccines ◽

10.3390/vaccines7030074 ◽

2019 ◽

Vol 7 (3) ◽

pp. 74 ◽

Cited By ~ 3

Author(s):

Karl Stefic ◽

Mélanie Bouvin-Pley ◽

Martine Braibant ◽

Francis Barin

Keyword(s):

Public Health ◽

Envelope Protein ◽

Neutralizing Antibodies ◽

Continuous Process ◽

Population Level ◽

Global Public Health ◽

Broadly Neutralizing Antibodies ◽

The Many ◽

The Impact ◽

Hiv 1

The HIV-1 pandemic remains a major burden on global public health and a vaccine to prevent HIV-1 infection is highly desirable but has not yet been developed. Among the many roadblocks to achieve this goal, the high antigenic diversity of the HIV-1 envelope protein (Env) is one of the most important and challenging to overcome. The recent development of broadly neutralizing antibodies has considerably improved our knowledge on Env structure and its interplay with neutralizing antibodies. This review aims at highlighting how the genetic diversity of HIV-1 thwarts current, and possibly future, vaccine developments. We will focus on the impact of HIV-1 Env diversification on the sensitivity to neutralizing antibodies and the repercussions of this continuous process at a population level.

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A Prime-Boost Immunization Strategy with Vaccinia Virus Expressing Novel gp120 Envelope Glycoprotein from a CRF02_AG Isolate Elicits Cross-Clade Tier 2 HIV-1 Neutralizing Antibodies

Vaccines ◽

10.3390/vaccines8020171 ◽

2020 ◽

Vol 8 (2) ◽

pp. 171

Author(s):

Rita Calado ◽

Joana Duarte ◽

Pedro Borrego ◽

José Maria Marcelino ◽

Inês Bártolo ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Envelope Glycoproteins ◽

The Novel ◽

Tier 2 ◽

Broadly Neutralizing Antibodies ◽

Immunization Strategy ◽

Vaccinia Viruses ◽

Boost Immunization ◽

Almost All ◽

Hiv 1

Development of new immunogens eliciting broadly neutralizing antibodies (bNAbs) is a main priority for the HIV-1 vaccine field. Envelope glycoproteins from non-B-non-C HIV-1clades have not been fully explored as components of a vaccine. We produced Vaccinia viruses expressing a truncated version of gp120 (gp120t) from HIV-1 clades CRF02_AG, H, J, B, and C and examined their immunogenicity in mice and rabbits. Mice primed with the recombinant Vaccinia viruses and boosted with the homologous gp120t or C2V3C3 polypeptides developed antibodies that bind potently to homologous and heterologous envelope glycoproteins. Notably, a subset of mice immunized with the CRF02_AG-based envelope immunogens developed a cross-reactive neutralizing response against tier 2 HIV-1 Env-pseudoviruses and primary isolates. Rabbits vaccinated with the CRF02_AG-based envelope immunogens also generated potent binding antibodies, and one animal elicited antibodies that neutralized almost all (13 of 16, 81.3%) tier 2 HIV-1 isolates tested. Overall, the results suggest that the novel CRF02_AG-based envelope immunogens and prime-boost immunization strategy elicit the type of immune responses required for a preventive HIV-1 vaccine.

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Broad neutralization by a combination of antibodies recognizing the CD4 binding site and a new conformational epitope on the HIV-1 envelope protein

Journal of Experimental Medicine ◽

10.1084/jem.20120423 ◽

2012 ◽

Vol 209 (8) ◽

pp. 1469-1479 ◽

Cited By ~ 123

Author(s):

Florian Klein ◽

Christian Gaebler ◽

Hugo Mouquet ◽

D. Noah Sather ◽

Clara Lehmann ◽

...

Keyword(s):

Binding Site ◽

Envelope Protein ◽

Neutralizing Antibodies ◽

Conformational Epitope ◽

Broadly Neutralizing Antibodies ◽

Cd4 Binding Site ◽

Capture Method ◽

Anti Hiv ◽

Hiv 1 ◽

Viral Isolates

Two to three years after infection, a fraction of HIV-1–infected individuals develop serologic activity that neutralizes most viral isolates. Broadly neutralizing antibodies that recognize the HIV-1 envelope protein have been isolated from these patients by single-cell sorting and by neutralization screens. Here, we report a new method for anti–HIV-1 antibody isolation based on capturing single B cells that recognize the HIV-1 envelope protein expressed on the surface of transfected cells. Although far less efficient than soluble protein baits, the cell-based capture method identified antibodies that bind to a new broadly neutralizing epitope in the vicinity of the V3 loop and the CD4-induced site (CD4i). The new epitope is expressed on the cell surface form of the HIV-1 spike, but not on soluble forms of the same envelope protein. Moreover, the new antibodies complement the neutralization spectrum of potent broadly neutralizing anti-CD4 binding site (CD4bs) antibodies obtained from the same individual. Thus, combinations of potent broadly neutralizing antibodies with complementary activity can account for the breadth and potency of naturally arising anti–HIV-1 serologic activity. Therefore, vaccines aimed at eliciting anti–HIV-1 serologic breadth and potency should not be limited to single epitopes.

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Virus-Like Particle Based Vaccines Elicit Neutralizing Antibodies against the HIV-1 Fusion Peptide

Vaccines ◽

10.3390/vaccines8040765 ◽

2020 ◽

Vol 8 (4) ◽

pp. 765

Author(s):

Alemu Tekewe Mogus ◽

Lihong Liu ◽

Manxue Jia ◽

Diane T. Ajayi ◽

Kai Xu ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccination Strategy ◽

Fusion Peptide ◽

Linear Epitope ◽

Broadly Neutralizing Antibodies ◽

Virus Like Particle ◽

Boost Immunization ◽

Potential Vaccine ◽

Hiv Envelope ◽

Hiv 1

Broadly neutralizing antibodies (bnAbs) isolated from HIV-infected individuals delineate vulnerable sites on the HIV envelope glycoprotein that are potential vaccine targets. A linear epitope within the N-terminal region of the HIV-1 fusion peptide (FP8) is the primary target of VRC34.01, a bnAb that neutralizes ~50% of primary HIV isolates. FP8 has attracted attention as a potential HIV vaccine target because it is a simple linear epitope. Here, platform technologies based on RNA bacteriophage virus-like particles (VLPs) were used to develop multivalent vaccines targeting the FP8 epitope. Both recombinant MS2 VLPs displaying the FP8 peptide and Qβ VLPs displaying chemically conjugated FP8 peptide induced high titers of FP8-specific antibodies in mice. Moreover, a heterologous prime-boost-boost regimen employing the two FP8-VLP vaccines and native envelope trimer was the most effective approach for eliciting HIV-1 neutralizing antibodies. Given the potent immunogenicity of VLP-based vaccines, this vaccination strategy—inspired by bnAb-guided epitope mapping, VLP bioengineering, and prime-boost immunization approaches—may be a useful strategy for eliciting bnAb responses against HIV.

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