Behavioral and social science research to support development of educational materials for clinical trials of broadly neutralizing antibodies for HIV treatment and prevention

Background/Aims Early integration of behavioral and social sciences research into clinical trials can improve trial conduct and facilitate future implementation of biomedical interventions. We sought to examine participants’ experiences in clinical trials with broadly neutralizing antibodies and describe the development of educational materials for use in future broadly neutralizing antibody research. Methods We conducted semi-structured interviews with trial participants in phase 1 trials evaluating safety and efficacy of broadly neutralizing antibodies for HIV prevention and treatment and key informants (i.e. trial staff involved in broadly neutralizing antibody research). Semi-structured interviews were transcribed and analyzed thematically. Based on findings from the interviews, we developed educational materials addressing concerns and misconceptions identified among trial participants with input from community and research stakeholders. Educational materials were used in subsequent clinical trials with broadly neutralizing antibodies. We evaluated trial staff’s experiences with newly developed educational materials in follow-up key informant interviews. Results Although most participants were concerned about long-term harms related to the investigational product upon enrollment, absence of severe side effects in the trial led to an underestimation of risks related to the study during trial participation. Participants showed a poor understanding of what broadly neutralizing antibodies are and the differences between broadly neutralizing antibodies and other HIV prevention and treatment products, such as antiretrovirals. Many trial participants overestimated the possible public health impact of the broadly neutralizing antibody trials in which they were enrolled, associating broadly neutralizing antibody research with the development of vaccine or cure for HIV in the near future. Based on these concerns and misconceptions among trial participants, we developed a frequently asked questions document and adapted an existing educational video about broadly neutralizing antibodies. In follow-up interviews, key informants reported that materials helped address trial participants’ concerns and questions related to the trial. Key informants reported using the educational materials not only during informed consent but also throughout trial participation, which contributed to making informed consent an “ongoing” process. Conclusion Integration of behavioral research into clinical trials with broadly neutralizing antibodies is key to identify and address key concerns among trial participants. Behavioral and social sciences research promotes communication between trial participants and biomedical researchers, facilitates engagement of participants and trial staff, and strengthens trial conduct. Development of educational materials collaboratively by behavioral and clinical scientists, trial staff, and community stakeholders is feasible and may help to address trial participants’ concerns and misconceptions. Future research should evaluate the impact of educational materials in recruitment and retention of trial participants.

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Vaccines and Broadly Neutralizing Antibodies for HIV-1 Prevention

Annual Review of Immunology ◽

10.1146/annurev-immunol-080219-023629 ◽

2020 ◽

Vol 38 (1) ◽

pp. 673-703 ◽

Cited By ~ 12

Author(s):

Kathryn E. Stephenson ◽

Kshitij Wagh ◽

Bette Korber ◽

Dan H. Barouch

Keyword(s):

Clinical Trials ◽

Neutralizing Antibodies ◽

Passive Immunization ◽

Neutralizing Antibody ◽

Broadly Neutralizing Antibodies ◽

Aids Pandemic ◽

Broadly Neutralizing Antibody ◽

Early Phase Clinical Trials ◽

Hiv 1 ◽

Review Current

Development of improved approaches for HIV-1 prevention will likely be required for a durable end to the global AIDS pandemic. Recent advances in preclinical studies and early phase clinical trials offer renewed promise for immunologic strategies for blocking acquisition of HIV-1 infection. Clinical trials are currently underway to evaluate the efficacy of two vaccine candidates and a broadly neutralizing antibody (bNAb) to prevent HIV-1 infection in humans. However, the vast diversity of HIV-1 is a major challenge for both active and passive immunization. Here we review current immunologic strategies for HIV-1 prevention, with a focus on current and next-generation vaccines and bNAbs.

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Functional development of a V3/glycan-specific broadly neutralizing antibody isolated from a case of HIV superinfection

eLife ◽

10.7554/elife.68110 ◽

2021 ◽

Vol 10 ◽

Author(s):

Mackenzie M Shipley ◽

Vidya Mangala Prasad ◽

Laura E Doepker ◽

Adam S Dingens ◽

Duncan K Ralph ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Viral Escape ◽

Single Infection ◽

Structural Studies ◽

Broadly Neutralizing Antibodies ◽

Hiv Vaccines ◽

Functional Development ◽

Broadly Neutralizing Antibody

Stimulating broadly neutralizing antibodies (bnAbs) directly from germline remains a barrier for HIV vaccines. HIV superinfection elicits bnAbs more frequently than single infection, providing clues of how to elicit such responses. We used longitudinal antibody sequencing and structural studies to characterize bnAb development from a superinfection case. BnAb QA013.2 bound initial and superinfecting viral Env, despite its probable naïve progenitor only recognizing the superinfecting strain, suggesting both viruses influenced this lineage. A 4.15 Å cryo-EM structure of QA013.2 bound to native-like trimer showed recognition of V3 signatures (N301/N332 and GDIR). QA013.2 relies less on CDRH3 and more on framework and CDRH1 for affinity and breadth compared to other V3/glycan-specific bnAbs. Antigenic profiling revealed that viral escape was achieved by changes in the structurally-defined epitope and by mutations in V1. These results highlight shared and novel properties of QA013.2 relative to other V3/glycan-specific bnAbs in the setting of sequential, diverse antigens.

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A single full-length VAR2CSA ectodomain variant purifies broadly neutralizing antibodies against placental malaria isolates

10.1101/2021.07.07.451420 ◽

2021 ◽

Author(s):

Justin Y.A. Doritchamou ◽

Jonathan P. Renn ◽

Bethany Jenkins ◽

Michal Fried ◽

Patrick E. Duffy

Keyword(s):

Surface Antigen ◽

Neutralizing Antibodies ◽

Placental Malaria ◽

Neutralizing Antibody ◽

Cross Reactivity ◽

Full Length ◽

Broadly Neutralizing Antibodies ◽

Protective Antibodies ◽

Broadly Neutralizing Antibody ◽

Specific Reactivity

Placental malaria (PM) is a deadly syndrome most frequent and severe in first pregnancies. PM results from accumulation of Plasmodium falciparum (Pf)-infected erythrocytes (IE) that express the surface antigen VAR2CSA and bind to chondroitin sulfate A (CSA) in the placenta. Women become PM-resistant over successive pregnancies as they develop anti adhesion and anti-VAR2CSA antibodies, supporting VAR2CSA as the leading PM-vaccine candidate. However, the first VAR2CSA subunit vaccines failed to induce broadly neutralizing antibody and it is still unclear whether naturally acquired protective antibodies target variant or conserved epitopes. This is crucial to determine whether effective vaccines will require incorporation of many or only a single VAR2CSA allele. Here, IgG from multigravidae was sequentially purified on five full-length VAR2CSA ectodomain variants, thereby depleting IgG reactivity to each. The five VAR2CSA variants purified ~0.7% of total IgG and yielded both strain-transcending and strain-specific reactivity to VAR2CSA and IE-surface antigen. IgG purified on the first VAR2CSA antigen displayed broad cross-reactivity to both recombinant and native VAR2CSA variants, and inhibited binding of all isolates to CSA. IgG remaining after depletion on all variants showed significantly reduced binding-inhibition activity compared to initial total IgG. These findings demonstrate that a single VAR2CSA ectodomain variant displays neutralizing epitopes shared by multiple parasites, including maternal isolates, and suggest that a broadly effective PM-vaccine can be achieved with a limited number of VAR2CSA variants.

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New Connections: Cell-to-Cell HIV-1 Transmission, Resistance to Broadly Neutralizing Antibodies, and an Envelope Sorting Motif

Journal of Virology ◽

10.1128/jvi.00149-17 ◽

2017 ◽

Vol 91 (9) ◽

Cited By ~ 2

Author(s):

S. Abigail Smith ◽

Cynthia A. Derdeyn

Keyword(s):

Neutralizing Antibodies ◽

Differential Susceptibility ◽

Neutralizing Antibody ◽

Dependent Manner ◽

Broadly Neutralizing Antibodies ◽

Cell Infection ◽

Viral Spread ◽

Broadly Neutralizing Antibody ◽

Hiv 1

ABSTRACT HIV-1 infection from cell-to-cell may provide an efficient mode of viral spread in vivo and could therefore present a significant challenge for preventative or therapeutic strategies based on broadly neutralizing antibodies. Indeed, Li et al. (H. Li, C. Zony, P. Chen, and B. K. Chen, J. Virol. 91:e02425-16, 2017, https://doi.org/10.1128/JVI.02425-16 ) showed that the potency and magnitude of multiple HIV-1 broadly neutralizing antibody classes are decreased during cell-to-cell infection in a context-dependent manner. A functional motif in gp41 appears to contribute to this differential susceptibility by modulating exposure of neutralization epitopes.

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Functional development of a V3-specific broadly neutralizing antibody isolated from a case of HIV superinfection

10.1101/2021.03.15.435484 ◽

2021 ◽

Author(s):

Mackenzie M. Shipley ◽

Vidya Mangala Prasad ◽

Laura E Doepker ◽

Adam S Dingens ◽

Duncan K Ralph ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Viral Escape ◽

Single Infection ◽

Structural Studies ◽

Broadly Neutralizing Antibodies ◽

Hiv Vaccines ◽

Functional Development ◽

Broadly Neutralizing Antibody

Stimulating broadly neutralizing antibodies (bnAbs) directly from germline remains a barrier for HIV vaccines. HIV superinfection elicits bnAbs more frequently than single infection, providing clues of how to elicit such responses. We used longitudinal antibody sequencing and structural studies to characterize bnAb development from a superinfection case. Mature bnAb QA013.2 bound both initial transmitted and superinfecting virus, but its inferred naïve bound only the superinfecting strain and was not neutralizing. QA013.2 requires residues spanning FWRH1-CDRH1 to attain breadth, which is uncommon for V3-specific bnAbs. A 4.15 Å cryo-EM structure of QA013.2 bound to heterologous native-like trimer showed recognition of V3 signatures (N301, N332, and GDIR). Antigenic profiling revealed that viral escape was achieved not only by changes in the structurally-defined epitope, but also by mutations in V1. These results highlight shared and distinct properties of QA013.2 relative to other V3-specific bnAbs in the setting of sequential, diverse antigenic variants.

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Engineering HIV envelope protein to activate germline B cell receptors of broadly neutralizing anti-CD4 binding site antibodies

Journal of Experimental Medicine ◽

10.1084/jem.20122824 ◽

2013 ◽

Vol 210 (4) ◽

pp. 655-663 ◽

Cited By ~ 195

Author(s):

Andrew T. McGuire ◽

Sam Hoot ◽

Anita M. Dreyer ◽

Adriana Lippy ◽

Andrew Stuart ◽

...

Keyword(s):

Binding Site ◽

Neutralizing Antibodies ◽

Variable Region ◽

Neutralizing Antibody ◽

Glycosylation Site ◽

Affinity Maturation ◽

Broadly Neutralizing Antibodies ◽

Cd4 Binding Site ◽

Broadly Neutralizing Antibody ◽

Hiv Envelope

Broadly neutralizing antibodies (bnAbs) against HIV are believed to be a critical component of the protective responses elicited by an effective HIV vaccine. Neutralizing antibodies against the evolutionarily conserved CD4-binding site (CD4-BS) on the HIV envelope glycoprotein (Env) are capable of inhibiting infection of diverse HIV strains, and have been isolated from HIV-infected individuals. Despite the presence of anti–CD4-BS broadly neutralizing antibody (bnAb) epitopes on recombinant Env, Env immunization has so far failed to elicit such antibodies. Here, we show that Env immunogens fail to engage the germline-reverted forms of known bnAbs that target the CD4-BS. However, we found that the elimination of a conserved glycosylation site located in Loop D and two glycosylation sites located in variable region 5 of Env allows Env-binding to, and activation of, B cells expressing the germline-reverted BCRs of two potent broadly neutralizing antibodies, VRC01 and NIH45-46. Our results offer a possible explanation as to why Env immunogens have been ineffective in stimulating the production of such bNAbs. Importantly, they provide key information as to how such immunogens can be engineered to initiate the process of antibody-affinity maturation against one of the most conserved Env regions.

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Trimeric Glycosylphosphatidylinositol-Anchored HCDR3 of Broadly Neutralizing Antibody PG16 Is a Potent HIV-1 Entry Inhibitor

Journal of Virology ◽

10.1128/jvi.01038-12 ◽

2012 ◽

Vol 87 (3) ◽

pp. 1899-1905 ◽

Cited By ~ 8

Author(s):

Lihong Liu ◽

Weiming Wang ◽

Lifei Yang ◽

Huanhuan Ren ◽

Jason T. Kimata ◽

...

Keyword(s):

Plasma Membrane ◽

Lipid Rafts ◽

Neutralizing Antibodies ◽

Quaternary Structure ◽

Neutralizing Antibody ◽

Entry Inhibitor ◽

Broadly Neutralizing Antibodies ◽

Broadly Neutralizing Antibody ◽

Anti Hiv ◽

Hiv 1

ABSTRACTPG9 and PG16 are two quaternary-structure-specific broadly neutralizing antibodies with unique HCDR3 subdomains. Previously, we showed that glycosylphosphatidylinositol (GPI)-anchored HCDR3 subdomains (GPI-HCDR3) can be targeted to lipid rafts of the plasma membrane, bind to the epitope recognized by HCDR3 of PG16, and neutralize diverse HIV-1 isolates. In this study, we further developed trimeric GPI-HCDR3s and demonstrated that trimeric GPI-HCDR3 (PG16) dramatically improves anti-HIV-1 neutralization, suggesting that a stoichiometry of recognition of 3 or 2 HCDR3 molecules (PG16) to 1 viral spike is possible.

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Influenza A HA's conserved epitopes and broadly neutralizing antibodies: A prediction method

Journal of Bioinformatics and Computational Biology ◽

10.1142/s0219720014500231 ◽

2014 ◽

Vol 12 (05) ◽

pp. 1450023 ◽

Cited By ~ 3

Author(s):

Jing Ren ◽

John Ellis ◽

Jinyan Li

Keyword(s):

Amino Acid ◽

Neutralizing Antibodies ◽

Influenza A ◽

Conservation Score ◽

Prediction Method ◽

Neutralizing Antibody ◽

Amino Acid Position ◽

Classification Performance ◽

Broadly Neutralizing Antibodies ◽

Broadly Neutralizing Antibody

A conserved epitope is an epitope retained by multiple strains of influenza as the key target of a broadly neutralizing antibody. Identification of conserved epitopes is of strong interest to help design broad-spectrum vaccines against influenza. Conservation score measures the evolutionary conservation of an amino acid position in a protein based on the phylogenetic relationships observed amongst homologous sequences. Here, Average Amino Acid Conservation Score (AAACS) is proposed as a method to identify HA's conserved epitopes. Our analysis shows that there is a clear distinction between conserved epitopes and nonconserved epitopes in terms of AAACS. This method also provides an excellent classification performance on an independent dataset. In contrast, alignment-based comparison methods do not work well for this problem, because conserved epitopes to the same broadly neutralizing antibody are usually not identical or similar. Location-based methods are not successful either, because conserved epitopes are located at both the less-conserved globular head (HA1) and the more-conserved stem (HA2). As a case study, two conserved epitopes on HA are predicted for the influenza A virus H7N9: One should match the broadly neutralizing antibodies CR9114 or FI6v3, while the other is new and requires validation by wet-lab experiments.

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Norovirus Escape from Broadly Neutralizing Antibodies Is Limited to Allostery-Like Mechanisms

mSphere ◽

10.1128/msphere.00334-17 ◽

2017 ◽

Vol 2 (5) ◽

Cited By ~ 19

Author(s):

Abimbola O. Kolawole ◽

Hong Q. Smith ◽

Sophia A. Svoboda ◽

Madeline S. Lewis ◽

Michael B. Sherman ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Neutralizing Antibody ◽

Antibody Binding ◽

Viral Fitness ◽

Broadly Neutralizing Antibodies ◽

Particle Assembly ◽

Escape Mutants ◽

Broadly Neutralizing Antibody ◽

P Domain

ABSTRACT The simplest and most common way for viruses to escape antibody neutralization is by mutating residues that are essential for antibody binding. Escape mutations are strongly selected for by their effect on viral fitness, which is most often related to issues of protein folding, particle assembly, and capsid function. The studies presented here demonstrated that a broadly neutralizing antibody to mouse norovirus binds to an exposed surface but that the only escape mutants that arose were distal to the antibody binding surface. To understand this finding, we performed an in silico analysis that suggested that those escape mutations blocked antibody binding by affecting structural plasticity. This kind of antigenic region—one that gives rise to broadly neutralizing antibodies but that the virus finds difficult to escape from—is therefore ideal for vaccine development. Ideal antiviral vaccines elicit antibodies (Abs) with broad strain recognition that bind to regions that are difficult to mutate for escape. Using 10 murine norovirus (MNV) strains and 5 human norovirus (HuNoV) virus-like particles (VLPs), we identified monoclonal antibody (MAb) 2D3, which broadly neutralized all MNV strains tested. Importantly, escape mutants corresponding to this antibody were very slow to develop and were distal to those raised against our previously studied antibody, A6.2. To understand the atomic details of 2D3 neutralization, we determined the cryo-electron microscopy (cryo-EM) structure of the 2D3/MNV1 complex. Interestingly, 2D3 binds to the top of the P domain, very close to where A6.2 binds, but the only escape mutations identified to date fall well outside the contact regions of both 2D3 and A6.2. To determine how mutations in distal residues could block antibody binding, we used molecular dynamics flexible fitting simulations of the atomic structures placed into the density map to examine the 2D3/MNV1 complex and these mutations. Our findings suggest that the escape mutant, V339I, may stabilize a salt bridge network at the P-domain dimer interface that, in an allostery-like manner, affects the conformational relaxation of the P domain and the efficiency of binding. They further highlight the unusual antigenic surface bound by MAb 2D3, one which elicits cross-reactive antibodies but which the virus is unable to alter to escape neutralization. These results may be leveraged to generate norovirus (NoV) vaccines containing broadly neutralizing antibodies. IMPORTANCE The simplest and most common way for viruses to escape antibody neutralization is by mutating residues that are essential for antibody binding. Escape mutations are strongly selected for by their effect on viral fitness, which is most often related to issues of protein folding, particle assembly, and capsid function. The studies presented here demonstrated that a broadly neutralizing antibody to mouse norovirus binds to an exposed surface but that the only escape mutants that arose were distal to the antibody binding surface. To understand this finding, we performed an in silico analysis that suggested that those escape mutations blocked antibody binding by affecting structural plasticity. This kind of antigenic region—one that gives rise to broadly neutralizing antibodies but that the virus finds difficult to escape from—is therefore ideal for vaccine development.

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Isolation of Porcine Reproductive and Respiratory Syndrome Virus GP5-Specific, Neutralizing Monoclonal Antibodies From Hyperimmune Sows

Frontiers in Immunology ◽

10.3389/fimmu.2021.638493 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jordan E. Young ◽

Cheryl M. T. Dvorak ◽

Simon P. Graham ◽

Michael P. Murtaugh

Keyword(s):

Monoclonal Antibodies ◽

B Cells ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Growing Pigs ◽

Respiratory Syndrome Virus ◽

Broadly Neutralizing Antibodies ◽

Complete Protection ◽

Broadly Neutralizing Antibody ◽

Neutralizing Epitopes

Porcine reproductive and respiratory syndrome (PRRS) is a devastating disease which impacts the pig industry worldwide. The disease is caused by PRRS viruses (PRRSV-1 and -2) which leads to abortions and other forms of reproductive failure in sows and severe respiratory disease in growing pigs. Current PRRSV vaccines provide limited protection; only providing complete protection against closely related strains. The development of improved PRRSV vaccines would benefit from an increased understanding of epitopes relevant to protection, including those recognized by antibodies which possess the ability to neutralize distantly related strains. In this work, a reverse vaccinology approach was taken; starting first with pigs known to have a broadly neutralizing antibody response and then investigating the responsible B cells/antibodies through the isolation of PRRSV neutralizing monoclonal antibodies (mAbs). PBMCs were harvested from pigs sequentially exposed to a modified-live PRRSV-2 vaccine as well as divergent PRRSV-2 field isolates. Memory B cells were immortalized and a total of 5 PRRSV-specific B-cell populations were isolated. All identified PRRSV-specific antibodies were found to be broadly binding to all PRRSV-2 isolates tested, but not PRRSV-1 isolates. Antibodies against GP5 protein, commonly thought to possess a dominant PRRSV neutralizing epitope, were found to be highly abundant, as four out of five B cells populations were GP5 specific. One of the GP5-specific mAbs was shown to be neutralizing but this was only observed against homologous and not heterologous PRRSV strains. Further investigation of these antibodies, and others, may lead to the elucidation of conserved neutralizing epitopes that can be exploited for improved vaccine design and lays the groundwork for the study of broadly neutralizing antibodies against other porcine pathogens.

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