scholarly journals New Member of the V1V2-Directed CAP256-VRC26 Lineage That Shows Increased Breadth and Exceptional Potency

2015 ◽  
Vol 90 (1) ◽  
pp. 76-91 ◽  
Author(s):  
Nicole A. Doria-Rose ◽  
Jinal N. Bhiman ◽  
Ryan S. Roark ◽  
Chaim A. Schramm ◽  
Jason Gorman ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies ◽  
New Members ◽  
Isolation And Characterization ◽  
The Family ◽  
Clade C ◽  
Potential Clinical Utility ◽  
Hiv 1 ◽  
Viral Isolates

ABSTRACT The epitopes defined by HIV-1 broadly neutralizing antibodies (bNAbs) are valuable templates for vaccine design, and studies of the immunological development of these antibodies are providing insights for vaccination strategies. In addition, the most potent and broadly reactive of these bNAbs have potential for clinical use. We previously described a family of 12 V1V2-directed neutralizing antibodies, CAP256-VRC26, isolated from an HIV-1 clade C-infected donor at years 1, 2, and 4 of infection (N. A. Doria-Rose et al., Nature 509:55–62, 2014, http://dx.doi.org/10.1038/nature13036 ). Here, we report on the isolation and characterization of new members of the family mostly obtained at time points of peak serum neutralization breadth and potency. Thirteen antibodies were isolated from B cell culture, and eight were isolated using trimeric envelope probes for differential single B cell sorting. One of the new antibodies displayed a 10-fold greater neutralization potency than previously published lineage members. This antibody, CAP256-VRC26.25, neutralized 57% of diverse clade viral isolates and 70% of clade C isolates with remarkable potency. Among the viruses neutralized, the median 50% inhibitory concentration was 0.001 μg/ml. All 33 lineage members targeted a quaternary epitope focused on V2. While all known bNAbs targeting the V1V2 region interact with the N160 glycan, the CAP256-VRC26 antibodies showed an inverse correlation of neutralization potency with dependence on this glycan. Overall, our results highlight the ongoing evolution within a single antibody lineage and describe more potent and broadly neutralizing members with potential clinical utility, particularly in areas where clade C is prevalent. IMPORTANCE Studies of HIV-1 broadly neutralizing antibodies (bNAbs) provide valuable information for vaccine design, and the most potent and broadly reactive of these bNAbs have potential for clinical use. We previously described a family of V1V2-directed neutralizing antibodies from an HIV-1 clade C-infected donor. Here, we report on the isolation and characterization of new members of the family mostly obtained at time points of peak serum neutralization breadth and potency. One of the new antibodies, CAP256-VRC26.25, displayed a 10-fold greater neutralization potency than previously described lineage members. It neutralized 57% of diverse clade viral isolates and 70% of clade C isolates with remarkable potency: the median 50% inhibitory concentration was 0.001 μg/ml. Our results highlight the ongoing evolution within a single antibody lineage and describe more potent and broadly neutralizing members with potential clinical utility, particularly in areas where clade C is prevalent.

scholarly journals An HIV-1 Broadly Neutralizing Antibody from a Clade C-Infected Pediatric Elite Neutralizer Potently Neutralizes the Contemporaneous and Autologous Evolving Viruses

2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Sanjeev Kumar ◽  
Harekrushna Panda ◽  
Muzamil Ashraf Makhdoomi ◽  
Nitesh Mishra ◽  
Haaris Ahsan Safdari ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Structural Information ◽  
Neutralizing Antibody ◽  
Elite Controller ◽  
Effective Vaccine ◽  
Protective Effects ◽  
Isolation And Characterization ◽  
Clade C ◽  
Hiv 1

ABSTRACT Broadly neutralizing antibodies (bNAbs) have demonstrated protective effects against HIV-1 in primate studies and recent human clinical trials. Elite neutralizers are potential candidates for isolation of HIV-1 bNAbs. The coexistence of bNAbs such as BG18 with neutralization-susceptible autologous viruses in an HIV-1-infected adult elite controller has been suggested to control viremia. Disease progression is faster in HIV-1-infected children than in adults. Plasma bNAbs with multiple epitope specificities are developed in HIV-1 chronically infected children with more potency and breadth than in adults. Therefore, we evaluated the specificity of plasma neutralizing antibodies of an antiretroviral-naive HIV-1 clade C chronically infected pediatric elite neutralizer, AIIMS_330. The plasma antibodies showed broad and potent HIV-1 neutralizing activity with >87% (29/33) breadth, a median inhibitory dilution (ID50) value of 1,246, and presence of N160 and N332 supersite-dependent HIV-1 bNAbs. The sorting of BG505.SOSIP.664.C2 T332N gp140 HIV-1 antigen-specific single B cells of AIIMS_330 resulted in the isolation of an HIV-1 N332 supersite-dependent bNAb, AIIMS-P01. The AIIMS-P01 neutralized 67% of HIV-1 cross-clade viruses, exhibited substantial indels despite limited somatic hypermutations, interacted with native-like HIV-1 trimer as observed in negative stain electron microscopy, and demonstrated high binding affinity. In addition, AIIMS-P01 neutralized the coexisting and evolving autologous viruses, suggesting the coexistence of vulnerable autologous viruses and HIV-1 bNAbs in the AIIMS_330 pediatric elite neutralizer. Such pediatric elite neutralizers can serve as potential candidates for isolation of novel HIV-1 pediatric bNAbs and for understanding the coevolution of virus and host immune response. IMPORTANCE More than 50% of the HIV-1 infections globally are caused by clade C viruses. To date, there is no effective vaccine to prevent HIV-1 infection. Based on the structural information of the currently available HIV-1 bNAbs, attempts are under way to design immunogens that can elicit correlates of protection upon vaccination. Here, we report the isolation and characterization of an HIV-1 N332 supersite-dependent bNAb, AIIMS-P01, from a clade C chronically infected pediatric elite neutralizer. The N332 supersite is an important epitope and is one of the current HIV-1 vaccine targets. AIIMS-P01 potently neutralized the contemporaneous and autologous evolving viruses and exhibited substantial indels despite low somatic hypermutations. Taken together with the information on infant bNAbs, further isolation and characterization of bNAbs contributing to the plasma breadth in HIV-1 chronically infected children may help provide a better understanding of their role in controlling HIV-1 infection.

scholarly journals Griffithsin Retains Anti-HIV-1 Potency with Changes in gp120 Glycosylation and Complements Broadly Neutralizing Antibodies PGT121 and PGT126

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Kathryn Fischer ◽  
Kimberly Nguyen ◽  
Patricia J. LiWang
Keyword(s):  
Neutralizing Antibodies ◽  
Glycosylation Site ◽  
Significant Loss ◽  
Broadly Neutralizing Antibodies ◽  
Clade B ◽  
Key Factor ◽  
Clade C ◽  
Cd4 Binding Site ◽  
Gp120 Glycosylation ◽  
Hiv 1

ABSTRACT Griffithsin (Grft) is an antiviral lectin that has been shown to potently inhibit HIV-1 by binding high-mannose N-linked glycosylation sites on HIV-1 gp120. A key factor for Grft potency is glycosylation at N295 of gp120, which is directly adjacent to N332, a target glycan for an entire class of broadly neutralizing antibodies (bNAbs). Here, we unify previous work on the importance of other glycans to Grft potency against HIV-1 and Grft’s role in mediating the conformational change of gp120 by mutating nearly every glycosylation site in gp120. In addition to a significant loss of Grft activity by the removal of glycosylation at N295, glycan absence at N332 or N448 was found to have moderate effects on Grft potency. Interestingly, in the absence of N295, Grft effectiveness could be improved by a mutation that results in the glycan at N448 shifting to N446, indicating that the importance of individual glycans may be related to their effect on glycosylation density. Grft’s ability to alter the structure of gp120, exposing the CD4 binding site, correlated with the presence of glycosylation at N295 only in clade B strains, not clade C strains. We further demonstrate that Grft can rescue the activity of the bNAbs PGT121 and PGT126 in the event of a loss or a shift of glycosylation at N332, where the bNAbs suffer a drastic loss of potency. Despite targeting the same region, Grft in combination with PGT121 and PGT126 produced additive effects. This indicates that Grft could be an important combinational therapeutic.

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

2012 ◽  
Vol 209 (8) ◽  
pp. 1469-1479 ◽  
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.

scholarly journals Optimal Combinations of Broadly Neutralizing Antibodies for Prevention and Treatment of HIV-1 Clade C Infection

2016 ◽  
Vol 12 (3) ◽  
pp. e1005520 ◽  
Author(s):  
Kshitij Wagh ◽  
Tanmoy Bhattacharya ◽  
Carolyn Williamson ◽  
Alex Robles ◽  
Madeleine Bayne ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies ◽  
Prevention And Treatment ◽  
Clade C ◽  
Hiv 1

scholarly journals Shedding-Resistant HIV-1 Envelope Glycoproteins Adopt Downstream Conformations That Remain Responsive to Conformation-Preferring Ligands

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Maolin Lu ◽  
Xiaochu Ma ◽  
Nick Reichard ◽  
Daniel S. Terry ◽  
James Arthos ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Envelope Glycoprotein ◽  
Neutralizing Antibodies ◽  
Conformational State ◽  
Broadly Neutralizing Antibodies ◽  
Membrane Bound ◽  
State 1 ◽  
Hiv 1 ◽  
Conformation State

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer of gp120-gp41 heterodimers mediates virus entry into CD4-positive (CD4+) cells. Single-molecule fluorescence resonance energy transfer (smFRET) has revealed that native Env on the surface of viruses predominantly exists in a pretriggered conformation (state 1) that is preferentially recognized by many broadly neutralizing antibodies (bNAbs). Env is activated by binding receptor CD4, which drives transitions through a default intermediate conformation (state 2) into the three-CD4-bound open conformation (state 3). The application of smFRET to assess the conformational state of existing Env constructs and ligand complexes recently revealed that all current high-resolution structures correspond to downstream states 2 and 3. The structure of state 1, therefore, remains unknown. We sought to identify conditions whereby HIV-1 Env could be stabilized in the pretriggered state 1 for possible structural characterization. Shedding of gp120, known to severely complicate structural studies, can be prevented by using the uncleaved gp160JR-FL precursor with alterations in the protease cleavage site (R508S/R511S) or by introducing a disulfide bridge between gp120 and gp41 designated “SOS” (A501C/T605C). smFRET demonstrated that both shedding-preventing modifications shifted the conformational landscape of Env downstream toward states 2 and 3. However, both membrane-bound Env proteins on the surface of intact viruses remained conformationally dynamic, responsive to state-stabilizing ligands, and able to be stabilized in state 1 by specific ligands such as the Bristol-Myers Squibb (BMS) entry inhibitors. The here-described identification of state 1-stabilizing conditions may enable structural characterization of the state 1 conformation of HIV-1 Env. IMPORTANCE The HIV-1 envelope glycoprotein (Env) opens in response to receptor CD4 binding from a pretriggered (state 1) conformation through a necessary intermediate to the three-CD4-bound conformation. The application of smFRET to test the conformational state of existing Env constructs and ligand complexes used for high-resolution structures recently revealed that they correspond to the downstream conformations. The structure of the pretriggered Env conformation, preferentially recognized by broadly neutralizing antibodies, remains unknown. Here, we identify experimental conditions that stabilize membrane-bound and shedding-resistant virus Env trimers in state 1, potentially facilitating structural characterization of this unknown conformational state.

scholarly journals An HIV-1 broadly neutralizing antibody from a clade C infected pediatric elite neutralizer potently neutralizes the contemporaneous and autologous evolving viruses

2018 ◽  
Author(s):  
Sanjeev Kumar ◽  
Harekrushna Panda ◽  
Muzamil Ashraf Makhdoomi ◽  
Nitesh Mishra ◽  
Haaris Ahsan Safdari ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Structural Information ◽  
Vaccine Design ◽  
Neutralizing Antibody ◽  
Elite Controller ◽  
Effective Vaccine ◽  
Protective Effects ◽  
Isolation And Characterization ◽  
Clade C ◽  
Hiv 1

AbstractBroadly neutralizing antibodies (bNAbs) have demonstrated protective effects against HIV-1 in primate studies and recent human clinical trials. Elite-neutralizers are potential candidates for isolation of HIV-1 bNAbs and coexistence of bNAbs such as BG18 with neutralization susceptible autologous viruses in an HIV-1 infected adult elite controller has been suggested to control viremia. Disease progression is faster in HIV-1 infected children than adults. Plasma bNAbs with multiple epitope specificities are developed in HIV-1 chronically infected children with more potency and breadth than in adults. Therefore, we evaluated the specificity of plasma neutralizing antibodies of an antiretroviral naïve HIV-1 clade C chronically infected pediatric elite neutralizer AIIMS_330. The plasma antibodies showed broad and potent HIV-1 neutralizing activity with >87% (29/33) breadth, median inhibitory dilution (ID50) value of 1246 and presence of N160 and N332-supersite dependent HIV-1 bNAbs. The sorting of BG505.SOSIP.664.C2 T332N gp140 HIV-1 antigen-specific single B cells of AIIMS_330 resulted in the isolation of an HIV-1 N332-supersite dependent bNAb AIIMS-P01. The AIIMS-P01 neutralized 67% of HIV-1 cross-clade viruses; exhibited substantial indels despite limited somatic hypermutations; interacted with native-like HIV-1 trimer as observed in negative stain electron microscopy and demonstrated high binding affinity. In addition, AIIMS-P01 potently neutralized the coexisting and evolving autologous viruses suggesting the coexistence of vulnerable autologous viruses and HIV-1 bNAbs in AIIMS_330 pediatric elite neutralizer. Further studies on such pediatric elite-neutralizers and isolation of novel HIV-1 pediatric bNAbs may provide newer insights to guide vaccine design.ImportanceMore than 50% of the HIV-1 infections globally are caused by clade C viruses. Till date, there is no effective vaccine to prevent HIV-1 infection. Based on the structural information of the currently available HIV-1 bNAbs, attempts are underway to design immunogens that can elicit correlates of protection upon vaccination. Here we report the isolation and characterization of an HIV-1 N332-supersite dependent bNAb AIIMS-P01 from a clade C chronically infected pediatric elite neutralizer. The N332-supersite is an important epitope and is one of the current HIV-1 vaccine targets. AIIMS-P01 potently neutralized the contemporaneous and autologous evolving viruses and exhibits substantial indels despite low somatic hypermutations. Taken together with the information on infant bNAbs, further isolation of bNAbs contributing to the plasma breadth in HIV-1 infected children may help to better understand their development and characteristics, which in turn may guide vaccine design.

scholarly journals Neutralizing Antibody Responses following Long-Term Vaccination with HIV-1 Env gp140 in Guinea Pigs

2018 ◽  
Vol 92 (13) ◽  
pp. e00369-18 ◽  
Author(s):  
Christine A. Bricault ◽  
James M. Kovacs ◽  
Alexander Badamchi-Zadeh ◽  
Krisha McKee ◽  
Jennifer L. Shields ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Neutralizing Antibodies ◽  
Antibody Responses ◽  
Tier 2 ◽  
Broadly Neutralizing Antibodies ◽  
Vaccination Regimen ◽  
Tier 1 ◽  
Clade C ◽  
Hiv 1

ABSTRACTA vaccination regimen capable of eliciting potent and broadly neutralizing antibodies (bNAbs) remains an unachieved goal of the HIV-1 vaccine field. Here, we report the immunogenicity of longitudinal prime/boost vaccination regimens with a panel of HIV-1 envelope (Env) gp140 protein immunogens over a period of 200 weeks in guinea pigs. We assessed vaccine regimens that included a monovalent clade C gp140 (C97ZA012 [C97]), a tetravalent regimen consisting of four clade C gp140s (C97ZA012, 459C, 405C, and 939C [4C]), and a tetravalent regimen consisting of clade A, B, C, and mosaic gp140s (92UG037, PVO.4, C97ZA012, and Mosaic 3.1, respectively [ABCM]). We found that the 4C and ABCM prime/boost regimens were capable of eliciting greater magnitude and breadth of binding antibody responses targeting variable loop 2 (V2) over time than the monovalent C97-only regimen. The longitudinal boosting regimen conducted over more than 2 years increased the magnitude of certain tier 1 NAb responses but did not increase the magnitude or breadth of heterologous tier 2 NAb responses. These data suggest that additional immunogen design strategies are needed to induce broad, high-titer tier 2 NAb responses.IMPORTANCEThe elicitation of potent, broadly neutralizing antibodies (bNAbs) remains an elusive goal for the HIV-1 vaccine field. In this study, we explored the use of a long-term vaccination regimen with different immunogens to determine if we could elicit bNAbs in guinea pigs. We found that longitudinal boosting over more than 2 years increased tier 1 NAb responses but did not increase the magnitude and breadth of tier 2 NAb responses. These data suggest that additional immunogen designs and vaccination strategies will be necessary to induce broad tier 2 NAb responses.

scholarly journals Tiered Categorization of a Diverse Panel of HIV-1 Env Pseudoviruses for Assessment of Neutralizing Antibodies

2009 ◽  
Vol 84 (3) ◽  
pp. 1439-1452 ◽  
Author(s):  
Michael S. Seaman ◽  
Holly Janes ◽  
Natalie Hawkins ◽  
Lauren E. Grandpre ◽  
Colleen Devoy ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Tier 2 ◽  
Average Sensitivity ◽  
Systematic Assessment ◽  
Immunodeficiency Virus ◽  
Tier 3 ◽  
High Tier ◽  
Hiv 1 ◽  
Viral Isolates

ABSTRACT The restricted neutralization breadth of vaccine-elicited antibodies is a major limitation of current human immunodeficiency virus-1 (HIV-1) candidate vaccines. In order to permit the efficient identification of vaccines with enhanced capacity for eliciting cross-reactive neutralizing antibodies (NAbs) and to assess the overall breadth and potency of vaccine-elicited NAb reactivity, we assembled a panel of 109 molecularly cloned HIV-1 Env pseudoviruses representing a broad range of genetic and geographic diversity. Viral isolates from all major circulating genetic subtypes were included, as were viruses derived shortly after transmission and during the early and chronic stages of infection. We assembled a panel of genetically diverse HIV-1-positive (HIV-1+) plasma pools to assess the neutralization sensitivities of the entire virus panel. When the viruses were rank ordered according to the average sensitivity to neutralization by the HIV-1+ plasmas, a continuum of average sensitivity was observed. Clustering analysis of the patterns of sensitivity defined four subgroups of viruses: those having very high (tier 1A), above-average (tier 1B), moderate (tier 2), or low (tier 3) sensitivity to antibody-mediated neutralization. We also investigated potential associations between characteristics of the viral isolates (clade, stage of infection, and source of virus) and sensitivity to NAb. In particular, higher levels of NAb activity were observed when the virus and plasma pool were matched in clade. These data provide the first systematic assessment of the overall neutralization sensitivities of a genetically and geographically diverse panel of circulating HIV-1 strains. These reference viruses can facilitate the systematic characterization of NAb responses elicited by candidate vaccine immunogens.

scholarly journals Antibody elicited by HIV-1 immunogen vaccination in macaques displaces Env fusion peptide and destroys a neutralizing epitope

2021 ◽  
Author(s):  
Morgan E Abernathy ◽  
Harry B Gristick ◽  
Jost Vielmetter ◽  
Jennifer R Keeffe ◽  
Priyanthi NP Gnanapragasam ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Fusion Peptide ◽  
Proximal Region ◽  
Fusion Peptides ◽  
Isolation And Characterization ◽  
Host Membrane ◽  
Immunogen Design ◽  
High Concentrations ◽  
Hiv 1

HIV-1 vaccine design aims to develop an immunogen that elicits broadly neutralizing antibodies against a desired epitope, while eliminating responses to off-target regions of HIV-1 Env. Here we report isolation and characterization of Ab1245, an off-target antibody against the Env gp120-gp41 interface, from V3-glycan patch immunogen-primed and boosted macaques. A 3.7 Å cryo-EM structure of an Ab1245-Env complex reveals one Ab1245 Fab binding asymmetrically to Env trimer at the gp120-gp41 interface using its long CDRH3 to mimic regions of gp41. The mimicry includes positioning of a CDRH3 methionine into the gp41 tryptophan clasp, resulting in displacement of the fusion peptide and fusion peptide-proximal region. Despite fusion peptide displacement, Ab1245 is non-neutralizing even at high concentrations, implying that only two fusion peptides per trimer are required for viral–host membrane fusion. These structural analyses facilitate immunogen design to prevent elicitation of Ab1245-like antibodies that block neutralizing antibodies against the fusion peptide.

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