Broadly binding and functional antibodies and persisting memory B cells elicited by HIV vaccine PDPHV.

Since publishing our original reports on the safety and immunogenicity of a polyvalent DNA prime-protein boost HIV vaccine (PDPHV) which elicited high titer antibody responses with broad specificity, neutralizing activities to multiple HIV-1 subtypes, as well as poly-functional T cell responses, accumulated findings from other HIV vaccine studies indicated the important roles of Ig isotype distribution, Fc medicated functions and the persistence of memory immune responses which were not studied in previous PDPHV related reports. The current report provides further detailed characterization of these parameters in human volunteers receiving the PDPHV regimen. Antibody responses were assessed using IgG isotype and gp70-V1V2-binding ELISAs, peptide arrays, and antibody-dependent cellular cytotoxicity (ADCC) assays. B cell ELISPOT was used to detect gp120-specific memory B cells. Our results showed that the gp120-specific antibodies were primarily of the IgG1 isotype. HIV-1 envelope protein variable regions V1 and V2 were actively targeted by the antibodies as determined by specific binding to both peptide and V1V2-carrying scaffolds. The antibodies showed potent and broad ADCC responses. Finally, the B cell ELISPOT analysis demonstrated persistence of gp120-specific memory B cells for at least 6 months after the last dose. These data indicate that broadly reactive binding Abs and ADCC responses as well as durable gp120-specific memory B cells were elicited by the polyvalent heterologous prime-boost vaccination regimens and showed great promise as a candidate HIV vaccine.

Glycan Profiles of gp120 Protein Vaccines from Four Major HIV-1 Subtypes Produced from Different Host Cell Lines under Non-GMP or GMP Conditions.

Envelope (Env) glycoprotein of human immunodeficiency virus type 1 (HIV-1) is an important target for the development of an HIV vaccine. Extensive glycosylation of Env is an important feature that both protects the virus from antibody responses and serves as a target for some highly potent broadly neutralizing antibodies. Therefore, analysis of glycans on recombinant Env proteins is highly significant. Here, we present glycosylation profiles of recombinant gp120 proteins from four major clades of HIV-1 (A, B, C, and AE), produced either as research-grade material in 293 and CHO cells or as two independent lots of clinical material under good manufacturing practice (GMP) conditions. Almost all potential N-linked glycosylation sites were at least partially occupied in all proteins. The occupancy rates were largely consistent among proteins produced under different conditions, although a few sites showed substantial variability even between the two GMP lots. Our data confirmed previous studies in the field, showing an abundance of oligomannose on Env protein, with 40 to 50% of glycans being Man5 to Man9 on all four proteins under all production conditions. Overall, the differences in occupancy and glycan forms among different Env subtypes produced under different conditions were less dramatic than anticipated, and antigenicity analysis with a panel of six monoclonal antibodies, including antibodies that recognize glycan forms, showed that all four gp120s maintained their antibody-binding profiles. Such findings have major implications for the final production of a clinical HIV vaccine with Env glycoprotein components.IMPORTANCE HIV-1 Env protein is a major target for the development of an HIV-1 vaccine. Env is covered with a large number of sugar-based glycan forms; about 50% of the Env molecular weight is composed of glycans. Glycan analysis of recombinant Env is important for understanding its roles in viral pathogenesis and immune responses. The current report presents the first extensive comparison of glycosylation patterns of recombinant gp120 proteins from four major clades of HIV-1 produced in two different cell lines, grown either under laboratory conditions or at 50-liter GMP scale in different lots. Information learned in this study is valuable for the further design and production of HIV-1 Env proteins as the critical components of HIV-1 vaccine formulations.

Harnessing Novel Imaging Approaches to Guide HIV Prevention and Cure Discoveries-A National Institutes of Health and Global HIV Vaccine Enterprise 2017 Meeting Report.

Advances in imaging technologies have greatly increased our understanding of cellular and molecular interactions in humans and their corresponding animal models of infectious diseases. In the HIV/SIV field, imaging has provided key insights into mucosal viral transmission, local and systemic virus spread, host-virus dynamics, and chronic inflammation/immune activation and the resultant immunopathology. Recent developments in imaging applications are yielding physical, spatial, and temporal measurements to enhance insight into biological functions and disease processes, while retaining important cellular, microenvironmental, organ, and intact organism contextual details. Taking advantage of the latest advancements in imaging technologies may help answer important questions in the HIV field. The Global HIV Vaccine Enterprise in collaboration with the National Institutes of Health (NIH) sponsored a meeting on May 8 and 9, 2017 to provide a platform to review state-of-the-art imaging technologies and to foster multidisciplinary collaborations in HIV/AIDS research. The meeting covered applications of imaging in studies of early events and pathogenesis, reservoirs, and cure, as well as in vaccine development. In addition, presentations and discussions of imaging applications from non-HIV biomedical research areas were included. This report summarizes the presentations and discussions at the meeting.

Recent progress in immune-based interventions to prevent HIV-1 transmission to children.

Globally, 150,000 new paediatric human immunodeficiency virus type 1 (HIV-1) infections occurred in 2015. There remain complex challenges to the global elimination of paediatric HIV-1 infection. Thus, for the global community to achieve elimination of new paediatric HIV-1 infections, innovative approaches need to be explored. Immune-based approaches to prevention of mother-to-child transmission (MTCT) may help fill some of the remaining gaps and provide new opportunities to achieve an AIDS-free generation. Immune-based interventions to prevent MTCT of HIV-1 may include paediatric HIV vaccines and passive immunization approaches. Recent discoveries providing evidence of robust immune responses to HIV in infants open new and exciting prospects for paediatric HIV vaccines. Moreover, successful vaccination of infants has a different set of requirements than vaccination of adults and may be easier to achieve. Proof-of-concept has been established over the last two decades that passively administered HIV-1 Env-specific monoclonal antibody (mAbs) can prevent chimeric simian human immunodeficiency virus (SHIV) transmission to newborn nonhuman primates. There has been tremendous progress in isolating and characterizing broadly neutralizing antibodies to HIV, and clinical testing of these antibodies for treatment and prevention in both infants and adults is a major effort in the field. Immune-based interventions need to be actively explored as they can provide critically important tools to address persistent challenges in MTCT prevention. It is a pivotal time for the field with active discussions on the best strategy to further reduce HIV infection of infants and accomplish the World Health Organization Fast-Track 2030 goals to eliminate new paediatric HIV infections.

Recent progress in immune-based interventions to prevent HIV-1 transmission to children

Globally, 150,000 new paediatric human immunodeficiency virus type 1 (HIV-1) infections occurred in 2015. There remain complex challenges to the global elimination of paediatric HIV-1 infection. Thus, for the global community to achieve elimination of new paediatric HIV-1 infections, innovative approaches need to be explored. Immune-based approaches to prevention of mother-to-child transmission (MTCT) may help fill some of the remaining gaps and provide new opportunities to achieve an AIDS-free generation. Immune-based interventions to prevent MTCT of HIV-1 may include paediatric HIV vaccines and passive immunization approaches. Recent discoveries providing evidence of robust immune responses to HIV in infants open new and exciting prospects for paediatric HIV vaccines. Moreover, successful vaccination of infants has a different set of requirements than vaccination of adults and may be easier to achieve. Proof-of-concept has been established over the last two decades that passively administered HIV-1 Env-specific monoclonal antibody (mAbs) can prevent chimeric simian human immunodeficiency virus (SHIV) transmission to newborn nonhuman primates. There has been tremendous progress in isolating and characterizing broadly neutralizing antibodies to HIV, and clinical testing of these antibodies for treatment and prevention in both infants and adults is a major effort in the field. Immune-based interventions need to be actively explored as they can provide critically important tools to address persistent challenges in MTCT prevention. It is a pivotal time for the field with active discussions on the best strategy to further reduce HIV infection of infants and accomplish the World Health Organization Fast-Track 2030 goals to eliminate new paediatric HIV infections.

Using Digital Technologies in Clinical HIV Research: Real-World Applications and Considerations for Future Work.

BACKGROUND: Digital technologies, especially if used in novel ways, provide a number of potential advantages to clinical research in trials related to human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) and may greatly facilitate operations as well as data collection and analysis. These technologies may even allow answering questions that are not answerable with older technologies. However, they come with a variety of potential concerns for both the participants and the trial sponsors. The exact challenges and means for alleviation depend on the technology and on the population in which it is deployed, and the rapidly changing landscape of digital technologies presents a challenge for creating future-proof guidelines for technology application. OBJECTIVE: The aim of this study was to identify and summarize some common themes that are frequently encountered by researchers in this context and highlight those that should be carefully considered before making a decision to include these technologies in their research. METHODS: In April 2016, the Global HIV Vaccine Enterprise surveyed the field for research groups with recent experience in novel applications of digital technologies in HIV clinical research and convened these groups for a 1-day meeting. Real-world uses of various technologies were presented and discussed by 46 attendees, most of whom were researchers involved in the design and conduct of clinical trials of biomedical HIV prevention and treatment approaches. After the meeting, a small group of organizers reviewed the presentations and feedback obtained during the meeting and categorized various lessons-learned to identify common themes. A group of 9 experts developed a draft summary of the findings that was circulated via email to all 46 attendees for review. Taking into account the feedback received, the group finalized the considerations that are presented here. RESULTS: Meeting presenters and attendees discussed the many successful applications of digital technologies to improve research outcomes, such as those for recruitment and enrollment, participant identification, informed consent, data collection, data quality, and protocol or treatment adherence. These discussions also revealed unintended consequence of technology usage, including risks to study participants and risks to study integrity. CONCLUSIONS: Key lessons learned from these discussions included the need to thoroughly evaluate systems to be used, the idea that early success may not be sustained throughout the study, that some failures will occur, and considerations for study-provided devices. Additionally, taking these key lessons into account, the group generated recommendations on how to move forward with the use of technology in HIV vaccine and biomedical prevention trials.

HIVR4P 2016, Partnering for Prevention: Conference Summary and Highlights.

HIV Research for Prevention: AIDS Vaccine, Microbicide, and ARV-based Prevention Science (HIVR4P) was built on a growing consensus that effective HIV prevention requires a combination of approaches and that understanding, analyzing, and debating the cross-cutting issues that impact prevention research are all essential to combat the global HIV/AIDS epidemic. To that end, the biennial HIVR4P conference is dedicated to all biomedical HIV prevention research approaches, including HIV vaccines, microbicides, pre-exposure prophylaxis, and treatment as prevention. The HIVR4P 2016 conference was held in Chicago, Illinois (USA), on October 17-21, and included more than 700 scientific presentations and 21 satellite sessions covering the latest and most promising advances across the HIV prevention research field. The theme "Partnering for Prevention" represented the conference's commitment to breaking down silos between research disciplines as well as between researchers, program developers, care providers, advocates, communities, and funders. Delegates spanning 42 countries attended the conference. One-third of those in attendance were early career investigators, which reflects a firm commitment to emerging researchers and ultimately to the goal of developing a sustainable scientific enterprise well into the future. This article presents a concise summary of highlights from the conference. For a more detailed account, one may find full abstracts, daily summaries, and webcasts on the conference website at hivr4p.org.

HIV vaccine-induced sero-reactivity: a challenge for trial participants, researchers, and physicians.

Antibody-inducing vaccines are a major focus in the preventive HIV vaccine field. Because the most common tests for HIV infection rely on detecting antibodies to HIV, they may also detect antibodies induced by a candidate HIV vaccine. The detection of vaccine-induced antibodies to HIV by serological tests is most commonly referred to as vaccine-induced sero-reactivity (VISR). VISR can be misinterpreted as a sign of HIV infection in a healthy study participant. In a participant who has developed vaccine-induced antibodies, accurate diagnosis of HIV infection (or lack thereof) may require specialized tests and algorithms (differential testing) that are usually not available in community settings. Organizations sponsoring clinical testing of preventive HIV vaccine candidates have an ethical obligation not only to inform healthy volunteers about the potential problems associated with participating in a clinical trial but also to help manage any resulting issues. This article explores the scope of VISR-related issues that become increasingly prevalent as the search for an effective HIV vaccine continues and will be paramount once a preventive vaccine is deployed. We also describe ways in which organizations conducting HIV vaccine trials have addressed these issues and outline areas where more work is needed.

HIV monoclonal antibodies: a new opportunity to further reduce mother-to-child HIV transmission.

Yegor Voronin and colleagues explore how monoclonal antibodies against HIV could provide a new opportunity to further reduce mother-to-child transmission of HIV and propose that new interventions should consider issues related to implementation, feasibility, and access. Please see later in the article for the Editors' Summary.

Organizing the HIV vaccine development effort.

PURPOSE OF REVIEW: To describe and compare the diverse organizational structures and funding mechanisms applied to advance HIV preventive vaccine research and development and to help explain and inform evolving infrastructures and collaborative funding models. RECENT FINDINGS: On the basis of models that have been tried, improved or abandoned over three decades, the field seems to have settled into a relatively stable set of diverse initiatives, each with its own organizational signature. At the same time, this set of organizations is forging cross-organizational collaborations, which promise to acquire newly emergent beneficial properties. SUMMARY: Strong motivation to expedite HIV vaccine R&D has driven a diversity of customized and inventive organizational approaches, largely government and foundation funded. Although no one approach has proven a panacea, the field has evolved into a constellation of often overlapping organizations that complement or reinforce one another. The Global HIV Vaccine Enterprise, a responsive, rapidly evolving loose infrastructure, is an innovative collaboration to catalyze that evolution.

Access to scientific publications: the scientist's perspective.

BACKGROUND: Scientific publishing is undergoing significant changes due to the growth of online publications, increases in the number of open access journals, and policies of funders and universities requiring authors to ensure that their publications become publicly accessible. Most studies of the impact of these changes have focused on the growth of articles available through open access or the number of open-access journals. Here, we investigated access to publications at a number of institutes and universities around the world, focusing on publications in HIV vaccine research--an area of biomedical research with special importance to the developing world. METHODS AND FINDINGS: We selected research papers in HIV vaccine research field, creating: 1) a first set of 50 most recently published papers with keywords "HIV vaccine" and 2) a second set of 200 articles randomly selected from those cited in the first set. Access to the majority (80%) of the recently published articles required subscription, while cited literature was much more accessible (67% freely available online). Subscriptions at a number of institutions around the world were assessed for providing access to subscription-only articles from the two sets. The access levels varied widely, ranging among institutions from 20% to 90%. Through the WHO-supported HINARI program, institutes in low-income countries had access comparable to that of institutes in the North. Finally, we examined the response rates for reprint requests sent to corresponding authors, a method commonly used before internet access became widespread. Contacting corresponding authors with requests for electronic copies of articles by email resulted in a 55-60% success rate, although in some cases it took up to 1.5 months to get a response. CONCLUSIONS: While research articles are increasingly available on the internet in open access format, institutional subscriptions continue to play an important role. However, subscriptions do not provide access to the full range of HIV vaccine research literature. Access to papers through subscriptions is complemented by a variety of other means, including emailing corresponding authors, joint affiliations, use of someone else's login information and posting requests on message boards. This complex picture makes it difficult to assess the real ability of scientists to access literature, but the observed differences in access levels between institutions suggest an unlevel playing field, in which some researchers have to spend more efforts than others to obtain the same information.

The future of HIV vaccine research and the role of the Global HIV Vaccine Enterprise.

PURPOSE OF REVIEW: This review covers the role of the Global HIV Vaccine Enterprise (the Enterprise), an alliance of independent organizations committed to development of a safe and effective HIV vaccine. It discusses the history, impact on the field, and future directions and initiatives of the alliance in the context of recent progress in HIV vaccine research and development. RECENT FINDINGS: Significant progress has been made in the field since the release of the 2005 Scientific Strategic Plan (the Plan) of the Enterprise. Over the last year, the Enterprise embarked on an impact assessment of the 2005 Plan and the development of the 2010 Plan. Enterprise Working Groups identified key priorities in the field, several of which are discussed in this review, including changing the nature, purpose and process of clinical trials, increasing and facilitating data sharing, and optimizing existing and mobilizing new resources. SUMMARY: This time is an important moment in HIV vaccine research. New clinical trial and laboratory results have created new opportunities to advance the search for an HIV vaccine and reinvigorated the field. The Enterprise will publish its 2010 Plan this year, providing a framework for setting new priorities and directions and encouraging new and existing partners to embark on a shared scientific agenda.

HIV/AIDS: vaccines and alternate strategies for treatment and prevention.

The symposium "HIV/AIDS: Vaccines and Alternate Strategies for Treatment and Prevention" brought together HIV vaccine researchers to discuss the latest developments in the field. From basic discoveries in virus diversity and mechanisms of neutralization by antibodies to nonhuman primate research and clinical trials of vaccine candidates in volunteers, scientists are making great strides in understanding the mechanisms that may protect against HIV and pathways to achieve this protection through vaccination.

Genetic drift of HIV populations in culture.

Populations of Human Immunodeficiency Virus type 1 (HIV-1) undergo a surprisingly large amount of genetic drift in infected patients despite very large population sizes, which are predicted to be mostly deterministic. Several models have been proposed to explain this phenomenon, but all of them implicitly assume that the process of virus replication itself does not contribute to genetic drift. We developed an assay to measure the amount of genetic drift for HIV populations replicating in cell culture. The assay relies on creation of HIV populations of known size and measurements of variation in frequency of a neutral allele. Using this assay, we show that HIV undergoes approximately ten times more genetic drift than would be expected from its population size, which we defined as the number of infected cells in the culture. We showed that a large portion of the increase in genetic drift is due to non-synchronous infection of target cells. When infections are synchronized, genetic drift for the virus is only 3-fold higher than expected from its population size. Thus, the stochastic nature of biological processes involved in viral replication contributes to increased genetic drift in HIV populations. We propose that appreciation of these effects will allow better understanding of the evolutionary forces acting on HIV in infected patients.

Primary isolates of human immunodeficiency virus type 1 are usually dominated by the major variants found in blood.

The isolation of primary strains of human immunodeficiency virus (HIV) is an invaluable tool for assessing properties of viruses replicating in HIV-infected subjects. A common method for obtaining a primary isolate is coculture of peripheral blood mononuclear cells (PBMCs) from HIV-infected subjects with PBMCs from uninfected donors. However, such in vitro expansion may disturb the composition (identities and relative proportions of constituting viral species) of the original viral population. We developed a GeneScan assay to monitor HIV populations by detecting variants that differ in the length of the V1/V2 coding region of the envelope gene. This assay was used to compare proviral DNAs from the PBMCs of eight subjects to the corresponding primary isolates. Major variants found in uncultured PBMCs usually persisted during culturing, while the minor variants frequently disappeared, resulting in a reduction in viral diversity. The outgrowth of the initial (2 to 4 days) viral population appeared to be determined by random events. However, subsequent changes in the population were deterministic, and as a result, the compositions of primary isolates from parallel cultures were often very similar. For two of three subjects studied, the source of HIV-negative PBMCs had little effect on the composition of primary isolates, while for the third subject donor-dependent effects were observed. Overall, our results show that most primary isolates accurately represent the major viruses found in a subject's blood and that rapid population-based genotyping methods are useful for detecting isolates with perturbed viral populations.

Determination of the ex vivo rates of human immunodeficiency virus type 1 reverse transcription by using novel strand-specific amplification analysis.

Replication of human immunodeficiency virus type 1 (HIV-1), like all organisms, involves synthesis of a minus-strand and a plus-strand of nucleic acid. Currently available PCR methods cannot distinguish between the two strands of nucleic acids. To carry out detailed analysis of HIV-1 reverse transcription from infected cells, we have developed a novel strand-specific amplification (SSA) assay using single-stranded padlock probes that are specifically hybridized to a target strand, ligated, and quantified for sensitive analysis of the kinetics of HIV-1 reverse transcription in cells. Using SSA, we have determined for the first time the ex vivo rates of HIV-1 minus-strand DNA synthesis in 293T and human primary CD4(+) T cells ( approximately 68 to 70 nucleotides/min). We also determined the rates of minus-strand DNA transfer ( approximately 4 min), plus-strand DNA transfer ( approximately 26 min), and initiation of plus-strand DNA synthesis ( approximately 9 min) in 293T cells. Additionally, our results indicate that plus-strand DNA synthesis is initiated at multiple sites and that several reverse transcriptase inhibitors influence the kinetics of minus-strand DNA synthesis differently, providing insights into their mechanism of inhibition. The SSA technology provides a novel approach to analyzing DNA replication processes and should facilitate the development of new antiretroviral drugs that target specific steps in HIV-1 reverse transcription.