Neutralization Characteristics of HIV-1 CRF01_AE Env Clones From Infections in China

Abstract Owing to the increasing prevalence of HIV-1 CRF01_AE, it is necessary to understand the neutralization properties of CRF01_AE and to develop broadly neutralizing monoclonal antibodies (bnmAbs) that can neutralize this virus. The full-length Env gene was cloned from HIV-1 CRF01_AE-infected plasma specimens collected in China and used to establish pseudoviruses. Neutralization phenotypes of the pseudoviruses were characterized with bnmAbs. The neutralizing activities of 11 bnmAbs VRC01, VRC03, IgG1b12 and 3BNC117 (targeting the CD4 binding site); PG9 (targeting the V1V2 region); 2G12 (targeting the high mannose patch), PGT135 and 10-1074 (targeting the V3 glycans); 2F5, 4E10 and 10E8 (targeting the membrane proximal external region), against 36 pseudoviruses were analyzed, demonstrating varying efficacies. In general, VRC01, 10E8 and 3BNC117 showed strong neutralizing activity, neutralizing more than 75% of the pseudoviruses; followed by PG9 and 4E10, showing moderate neutralizing activity with neutralization of 50%–60% of the pseudoviruses; whereas the efficacies of the remaining bnmAbs were poor, neutralizing less than 15% of pseudoviruses tested. Env variants of CRF01_AE from one infection also showed significant differences in resistance to neutralization. These characterized HIV-1 CRF01_AE pseudoviruses could be used for neutralization studies and evaluation of vaccines or anti-HIV-1 products in China.

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Neutralization Characteristics HIV-1 CRF01_AE Env Clones from Infections in China

10.21203/rs.3.rs-568729/v1 ◽

2021 ◽

Author(s):

Xinyu Zhang ◽

Zehua Zhou ◽

Xueli Li ◽

Yimeng An ◽

Fei Jiang ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Binding Site ◽

External Region ◽

Sugar Chain ◽

Neutralizing Activity ◽

Cd4 Binding Site ◽

Anti Hiv ◽

V3 Region ◽

Hiv 1 ◽

V1v2 Region

Abstract Owing to the increasing prevalence of HIV-1 CRF_01AE, it is necessary to understand the neutralization properties of CRF_01AE and to develop broadly neutralizing monoclonal antibodies (bnmAbs) that can neutralize this virus. The full-length Env gene was cloned from HIV-1 CRF01_AE-infected plasma specimens collected in China and used to establish pseudoviruses. Neutralization phenotypes of the pseudoviruses were characterized with bnmAbs. The neutralizing activities of 11 bnmAbs VRC01, VRC03, IgG1b12 and 3BNC117 (targeting the CD4 binding site); PG9 (targeting the V1V2 region); 2G12 (sugar chain specific), PGT135 and 10-1074 (targeting the V3 region); 2F5, 4E10 and 10E8 (targeting the membrane proximal external region), against 36 pseudoviruses were analyzed, demonstrating varying efficacies. In general, VRC01, 10E8 and 3BNC117 showed strong neutralizing activity, neutralizing more than 75% of the pseudoviruses; followed by PG9 and 4E10, showing moderate neutralizing activity with neutralization of 50%–60% of the pseudoviruses; whereas the efficacies of the remaining bnmAbs were poor, neutralizing less than 15% of pseudoviruses tested. Env variants of CRF_01AE also showed significant differences in resistance to neutralization. CRF_01AE Env variants pose a serious challenge for the development of bnmAbs and vaccines, and these characterized HIV-1 CRF_01AE pseudoviruses could be used for neutralization studies and evaluation of vaccines or anti-HIV-1 products in China.

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Monoclonal Antibodies Specific for the V2, V3, CD4-Binding Site, and gp41 of HIV-1 Mediate Phagocytosis in a Dose-Dependent Manner

Journal of Virology ◽

10.1128/jvi.02325-16 ◽

2017 ◽

Vol 91 (8) ◽

Cited By ~ 26

Author(s):

Thomas Musich ◽

Liuzhe Li ◽

Lily Liu ◽

Susan Zolla-Pazner ◽

Marjorie Robert-Guroff ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Binding Site ◽

Protective Efficacy ◽

Area Under The Curve ◽

Protective Role ◽

Hybridoma Cells ◽

Dependent Manner ◽

Cd4 Binding Site ◽

Anti Hiv ◽

Hiv 1

ABSTRACT In light of the weak or absent neutralizing activity mediated by anti-V2 monoclonal antibodies (MAbs), we tested whether they can mediate Ab-dependent cellular phagocytosis (ADCP), which is an important element of anti-HIV-1 immunity. We tested six anti-V2 MAbs and compared them with 21 MAbs specific for V3, the CD4-binding site (CD4bs), and gp41 derived from chronically HIV-1-infected individuals and produced by hybridoma cells. ADCP activity was measured by flow cytometry using uptake by THP-1 monocytic cells of fluorescent beads coated with gp120, gp41, BG505 SOSIP.664, or BG505 DS-SOSIP.664 complexed with MAbs. The measurement of ADCP activity by the area under the curve showed significantly higher activity of anti-gp41 MAbs than of the members of the three other groups of MAbs tested using beads coated with monomeric gp41 or gp120; anti-V2 MAbs were dominant compared to anti-V3 and anti-CD4bs MAbs against clade C gp120ZM109. ADCP activity mediated by V2 and V3 MAbs was positive against stabilized DS-SOSIP.664 trimer but negligible against SOSIP.664 targets, suggesting that a closed envelope conformation better exposes the variable loops. Two IgG3 MAbs against the V2 and V3 regions displayed dominant ADCP activity compared to a panel of IgG1 MAbs. This superior ADCP activity was confirmed when two of three recombinant IgG3 anti-V2 MAbs were compared to their IgG1 counterparts. The study demonstrated dominant ADCP activity of anti-gp41 against monomers but not trimers, with some higher activity of anti-V2 MAbs than of anti-V3 and anti-CD4bs MAbs. The ability to mediate ADCP suggests a mechanism by which anti-HIV-1 envelope Abs can contribute to protective efficacy. IMPORTANCE Anti-V2 antibodies (Abs) correlated with reduced risk of HIV-1 infection in recipients of the RV144 vaccine, suggesting that they play a protective role, but a mechanism providing such protection remains to be determined. The rare and weak neutralizing activities of anti-V2 MAbs prompted us to study Fc-mediated activities. We compared anti-V2 MAbs with other MAbs specific for V3, CD4bs, and gp41 for Ab-dependent cellular phagocytosis (ADCP) activity, implicated in protective immunity. The anti-V2 MAbs displayed stronger activity than other anti-gp120 MAbs in screening against one of two gp120s and against DS-SOSIP, which mimics the native trimer. The activity of anti-gp41 MAbs was superior in targeting monomeric gp41 but was comparable to that seen against trimers, which may not adequately expose gp41 epitopes. While anti-envelope MAbs in general mediated ADCP activity, anti-V2 MAbs displayed some dominance compared to other MAbs. Our demonstration that anti-V2 MAbs mediate ADCP activity suggests a functional mechanism for their contribution to protective efficacy.

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Anti-HIV-1 Response Elicited in Rabbits by Anti-Idiotype Monoclonal Antibodies Mimicking the CD4-Binding Site

PLoS ONE ◽

10.1371/journal.pone.0003423 ◽

2008 ◽

Vol 3 (10) ◽

pp. e3423 ◽

Cited By ~ 18

Author(s):

Roberto Burioni ◽

Nicasio Mancini ◽

Donata De Marco ◽

Nicola Clementi ◽

Mario Perotti ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Binding Site ◽

Cd4 Binding Site ◽

Anti Hiv ◽

Hiv 1

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Human Anti–HIV-1 gp120 Monoclonal Antibodies with Neutralizing Activity Cloned from Humanized Mice Infected with HIV-1

The Journal of Immunology ◽

10.4049/jimmunol.1801085 ◽

2018 ◽

Vol 202 (3) ◽

pp. 799-804 ◽

Cited By ~ 3

Author(s):

Melissa A. Gawron ◽

Mark Duval ◽

Claudia Carbone ◽

Smita Jaiswal ◽

Aaron Wallace ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Humanized Mice ◽

Neutralizing Activity ◽

Anti Hiv ◽

Hiv 1

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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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Anti-V3/Glycan and Anti-MPER Neutralizing Antibodies, but Not Anti-V2/Glycan Site Antibodies, Are Strongly Associated with Greater Anti-HIV-1 Neutralization Breadth and Potency

Journal of Virology ◽

10.1128/jvi.00129-15 ◽

2015 ◽

Vol 89 (10) ◽

pp. 5264-5275 ◽

Cited By ~ 23

Author(s):

Rajesh Abraham Jacob ◽

Thandeka Moyo ◽

Michael Schomaker ◽

Fatima Abrahams ◽

Berta Grau Pujol ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Prediction Interval ◽

Vaccine Design ◽

Broadly Neutralizing Antibodies ◽

External Region ◽

Membrane Proximal External Region ◽

Site Recognition ◽

Anti Hiv ◽

Glycan Site ◽

Hiv 1

ABSTRACTThe membrane-proximal external region (MPER), the V2/glycan site (initially defined by PG9 and PG16 antibodies), and the V3/glycans (initially defined by PGT121–128 antibodies) are targets of broadly neutralizing antibodies and potential targets for anti-HIV-1 antibody-based vaccines. Recent evidence shows that antibodies with moderate neutralization breadth are frequently attainable, with 50% of sera from chronically infected individuals neutralizing ≥50% of a large, diverse set of viruses. Nonetheless, there is little systematic information addressing which specificities are preferentially targeted among such commonly found, moderately broadly neutralizing sera. We explored associations between neutralization breadth and potency and the presence of neutralizing antibodies targeting the MPER, V2/glycan site, and V3/glycans in sera from 177 antiretroviral-naive HIV-1-infected (>1 year) individuals. Recognition of both MPER and V3/glycans was associated with increased breadth and potency. MPER-recognizing sera neutralized 4.62 more panel viruses than MPER-negative sera (95% prediction interval [95% PI], 4.41 to 5.20), and V3/glycan-recognizing sera neutralized 3.24 more panel viruses than V3/glycan-negative sera (95% PI, 3.15 to 3.52). In contrast, V2/glycan site-recognizing sera neutralized only 0.38 more panel viruses (95% PI, 0.20 to 0.45) than V2/glycan site-negative sera and no association between V2/glycan site recognition and breadth or potency was observed. Despite autoreactivity of many neutralizing antibodies recognizing MPER and V3/glycans, antibodies to these sites are major contributors to neutralization breadth and potency in this cohort. It may therefore be appropriate to focus on developing immunogens based upon the MPER and V3/glycans.IMPORTANCEPrevious candidate HIV vaccines have failed either to induce wide-coverage neutralizing antibodies or to substantially protect vaccinees. Therefore, current efforts focus on novel approaches never before successfully used in vaccine design, including modeling epitopes. Candidate immunogen models identified by broadly neutralizing antibodies include the membrane-proximal external region (MPER), V3/glycans, and the V2/glycan site. Autoreactivity and polyreactivity of anti-MPER and anti-V3/glycan antibodies are thought to pose both direct and indirect barriers to achieving neutralization breadth. We found that antibodies to the MPER and the V3/glycans contribute substantially to neutralization breadth and potency. In contrast, antibodies to the V2/glycan site were not associated with neutralization breadth/potency. This suggests that the autoreactivity effect is not critical and that the MPER and the V3/glycans should remain high-priority vaccine candidates. The V2/glycan site result is surprising because broadly neutralizing antibodies to this site have been repeatedly observed. Vaccine design priorities should shift toward the MPER and V3/glycans.

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Simian Immunodeficiency Virus Engrafted with Human Immunodeficiency Virus Type 1 (HIV-1)-Specific Epitopes: Replication, Neutralization, and Survey of HIV-1-Positive Plasma

Journal of Virology ◽

10.1128/jvi.80.6.3030-3041.2006 ◽

2006 ◽

Vol 80 (6) ◽

pp. 3030-3041 ◽

Cited By ~ 58

Author(s):

Eloisa Yuste ◽

Hannah B. Sanford ◽

Jill Carmody ◽

Jacqueline Bixby ◽

Susan Little ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Monoclonal Antibodies ◽

Human Plasma ◽

Plasma Sample ◽

Plasma Samples ◽

Neutralizing Activity ◽

Immunodeficiency Virus ◽

Anti Hiv ◽

Hiv 1

ABSTRACT To date, only a small number of anti-human immunodeficiency virus type 1 (HIV-1) monoclonal antibodies (MAbs) with relatively broad neutralizing activity have been isolated from infected individuals. Adequate techniques for defining how frequently antibodies of these specificities arise in HIV-infected people have been lacking, although it is generally assumed that such antibodies are rare. In order to create an epitope-specific neutralization assay, we introduced well-characterized HIV-1 epitopes into the heterologous context of simian immunodeficiency virus (SIV). Specifically, epitope recognition sequences for the 2F5, 4E10, and 447-52D anti-HIV-1 neutralizing monoclonal antibodies were introduced into the corresponding regions of SIVmac239 by site-directed mutagenesis. Variants with 2F5 or 4E10 recognition sequences in gp41 retained replication competence and were used for neutralization assays. The parental SIVmac239 and the neutralization-sensitive SIVmac316 were not neutralized by the 2F5 and 4E10 MAbs, nor were they neutralized significantly by any of the 96 HIV-1-positive human plasma samples that were tested. The SIV239-2F5 and SIV239-4E10 variants were specifically neutralized by the 2F5 and 4E10 MAbs, respectively, at concentrations within the range of what has been reported previously for HIV-1 primary isolates (J. M. Binley et al., J. Virol. 78:13232-13252, 2004). The SIV239-2F5 and SIV239-4E10 epitope-engrafted variants were used as biological screens for the presence of neutralizing activity of these specificities. None of the 92 HIV-1-positive human plasma samples that were tested exhibited significant neutralization of SIV239-2F5. One plasma sample exhibited >90% neutralization of SIV239-4E10, but this activity was not competed by a 4E10 target peptide and was not present in concentrated immunoglobulin G (IgG) or IgA fractions. We thus confirm by direct analysis that neutralizing activities of the 2F5 and 4E10 specificities are either rare among HIV-1-positive individuals or, if present, represent only a very small fraction of the total neutralizing activity in any given plasma sample. We further conclude that the structures of gp41 from SIVmac239 and HIV-1 are sufficiently similar such that epitopes engrafted into SIVmac239 can be readily recognized by the cognate anti-HIV-1 monoclonal antibodies.

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