HIV-1 vaccine development has been stymied by an inability to induce broadly reactive neutralizing antibodies to the envelope (Env) trimer, the sole viral antigen on the virion surface. Antibodies ...isolated from HIV-1-infected donors, however, have been shown to recognize all major exposed regions of the prefusion-closed Env trimer, and an emerging understanding of the immunological and structural characteristics of these antibodies and the epitopes they recognize is enabling new approaches to vaccine design. Antibody lineage-based design creates immunogens that activate the naive ancestor-B cell of a target antibody lineage and that mature intermediate-B cells toward effective neutralization, with proof of principle achieved with select HIV-1-neutralizing antibody lineages in human-gene knock-in mouse models. Epitope-based vaccine design involves the engineering of sites of Env vulnerability as defined by the recognition of broadly neutralizing antibodies, with cross-reactive neutralizing antibodies elicited in animal models. Both epitope-based and antibody lineage-based HIV-1 vaccine approaches are being readied for human clinical trials.
Kwong and Mascola review vaccine approaches to overcome the formidable challenge of eliciting effective antibodies against HIV-1. The structural and immunological information provided by analysis of infection-elicited broadly neutralizing antibodies provides a framework for antibody-to-vaccine approaches of vaccine design.
Antibodies that neutralize diverse strains of HIV-1 develop in ∼20% of HIV-1-infected individuals, and isolation and structural characterization of these antibodies are revealing how they recognize ...the envelope glycoprotein spike. Broadly reactive neutralizing antibodies utilize just a few sites of spike vulnerability and converge on select modes of recognition. These antibodies have unusual features: uncommonly long complementarity-determining loops, extensive somatic mutation, or both. Recent advances in next-generation sequencing of antibody-gene transcripts are providing genetic records of the development of neutralizing antibodies. These records inform an understanding of the naive B cell repertoire, of somatic mutation, and of the resulting antibody features that are critical to effective HIV-1 neutralization; based on these, we propose an ontogeny and structure-based system of antibody classification. The human immune system is capable of developing antibodies that broadly neutralize HIV-1—and an increasingly detailed view is accumulating for how effective immunity against HIV-1 can be generated.
A strategic approach to COVID-19 vaccine R&D Corey, Lawrence; Mascola, John R; Fauci, Anthony S ...
Science (American Association for the Advancement of Science),
05/2020, Letnik:
368, Številka:
6494
Journal Article
Recenzirano
Odprti dostop
A public-private partnership and platform for harmonized clinical trials aims to accelerate licensure and distribution
There is an unprecedented need to manufacture and distribute enough safe and ...effective vaccine to immunize an extraordinarily large number of individuals in order to protect the entire global community from the continued threat of morbidity and mortality from severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2). The global need for vaccine and the wide geographic diversity of the pandemic require more than one effective vaccine approach. Collaboration will be essential among biotechnology and pharmaceutical companies, many of which are bringing forward a variety of vaccine approaches (
1
). The full development pathway for an effective vaccine for SARS-CoV-2 will require that industry, government, and academia collaborate in unprecedented ways, each adding their individual strengths. We discuss one such collaborative program that has recently emerged: the ACTIV (Accelerating COVID-19 Therapeutic Interventions and Vaccines) public-private partnership. Spearheaded by the U.S. National Institutes of Health (NIH), this effort brings together the strengths of all sectors at this time of global urgency. We further discuss a collaborative platform for conducting harmonized, randomized controlled vaccine efficacy trials. This mechanism aims to generate essential safety and efficacy data for several candidate vaccines in parallel, so as to accelerate the licensure and distribution of multiple vaccine platforms and vaccines to protect against COVID-19 (coronavirus disease 2019).
Summary
The development of an effective vaccine has been hindered by the enormous diversity of human immunodeficiency virus‐1 (HIV‐1) and its ability to escape a myriad of host immune responses. In ...addition, conserved vulnerable regions on the HIV‐1 envelope glycoprotein are often poorly immunogenic and elicit broadly neutralizing antibody responses (BNAbs) in a minority of HIV‐1‐infected individuals and only after several years of infection. All of the known BNAbs demonstrate high levels of somatic mutations and often display other unusual traits, such as a long heavy chain complementarity determining region 3 (CDRH3) and autoreactivity that can be limited by host tolerance controls. Nonetheless, the demonstration that HIV‐1‐infected individuals can make potent BNAbs is encouraging, and recent progress in isolating such antibodies and mapping their immune pathways of development is providing new strategies for vaccination.
This Viewpoint discusses the potential role of neutralizing monoclonal antibodies (MAbs) as a treatment for coronavirus disease 2019 (COVID-19) and as a means of prevention in high-risk populations, ...and it also raises possible limitations of the approach that need to be disproven or addressed for the strategy to be effective.
The development of effective vaccines to combat infectious diseases is a complex multi-year and multi-stakeholder process. To accelerate the development of vaccines for coronavirus disease 2019 ...(COVID-19), a novel pathogen emerging in late 2019 and spreading globally by early 2020, the United States government (USG) mounted an operation bridging public and private sector expertise and infrastructure. The success of the endeavor can be seen in the rapid advanced development of multiple vaccine candidates, with several demonstrating efficacy and now being administered around the globe. Here, we review the milestones enabling the USG-led effort, the methods utilized, and ensuing outcomes. We discuss the current status of COVID-19 vaccine development and provide a perspective for how partnership and preparedness can be better utilized in response to future public-health pandemic emergencies.
The development of effective vaccines to combat infectious diseases is a complex multi-year and multi-stakeholder process. To accelerate the development of vaccines for coronavirus disease 2019 (COVID-19), a novel pathogen emerging in late 2019 and spreading globally by early 2020, the United States government (USG) mounted an operation bridging public and private sector expertise and infrastructure. The success of the endeavor can be seen in the rapid advanced development of multiple vaccine candidates, with several demonstrating efficacy and now being administered around the globe. Here, we review the milestones enabling the USG-led effort, the methods utilized, and ensuing outcomes. We discuss the current status of COVID-19 vaccine development and provide a perspective for how partnership and preparedness can be better utilized in response to future public-health pandemic emergencies.
Antibody responses to the HIV-1 envelope glycoproteins can be classified into three groups. Binding but non-neutralizing responses are directed to epitopes that are expressed on isolated envelope ...glycoproteins but not on the native envelope trimer found on the surface of virions and responsible for mediating the entry of virus into target cells. Strain-specific responses and broadly neutralizing responses, in contrast, target epitopes that are expressed on the native trimer, as revealed by recently resolved structures. The past few years have seen the isolation of many broadly neutralizing antibodies of remarkable potency that have shown prophylactic and therapeutic activities in animal models. These antibodies are helping to guide rational vaccine design and therapeutic strategies for HIV-1.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Licensed vaccines against viral diseases generate antibodies that neutralize the infecting virus and protect against infection or disease. Similarly, an effective vaccine against HIV-1 will likely ...need to induce antibodies that prevent initial infection of host cells or that limit early events of viral dissemination. Such antibodies must target the surface envelope glycoproteins of HIV-1, which are highly variable in sequence and structure. The first subunit vaccines to enter clinical trails were safe and immunogenic but unable to elicit antibodies that neutralized most circulating strains of HIV-1. However, potent virus neutralizing antibodies (NAbs) can develop during the course of HIV-1 infection, and this is the type of antibody response that researchers seek to generate with a vaccine. Thus, current vaccine design efforts have focused on a more detailed understanding of these broadly neutralizing antibodies and their epitopes to inform the design of improved vaccines.
Epstein-Barr virus (EBV) represents a major global health problem. Though it is associated with infectious mononucleosis and ∼200,000 cancers annually worldwide, a vaccine is not available. The major ...target of immunity is EBV glycoprotein 350/220 (gp350) that mediates attachment to B cells through complement receptor 2 (CR2/CD21). Here, we created self-assembling nanoparticles that displayed different domains of gp350 in a symmetric array. By focusing presentation of the CR2-binding domain on nanoparticles, potent neutralizing antibodies were elicited in mice and non-human primates. The structurally designed nanoparticle vaccine increased neutralization 10- to 100-fold compared to soluble gp350 by targeting a functionally conserved site of vulnerability, improving vaccine-induced protection in a mouse model. This rational approach to EBV vaccine design elicited potent neutralizing antibody responses by arrayed presentation of a conserved viral entry domain, a strategy that can be applied to other viruses.
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•Self-assembling nanoparticles present the conserved gp350 receptor-binding domain•The nanoparticles elicit more potent neutralizing antibodies than soluble gp350•These neutralizing antibodies predominantly target the CR2-binding site on gp350•The nanoparticles elicit potent neutralizing antibodies in mice and non-human primates
Structurally designed EBV vaccine candidates based on self-assembling nanoparticles elicit potent and durable virus-neutralizing antibodies that target the receptor-binding site on the viral envelope protein gp350, a site of vulnerability, serving as a template to develop an EBV vaccine and providing a basis for immunofocusing through rational vaccine design.
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