1
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Galvez NM, Cao Y, Nitido AD, Deal CE, Boutros CL, MacDonald SW, Albrecht YES, Lam EC, Sheehan ML, Parsons D, Lin AZ, Deymier MJ, Brady JM, Moon B, Bullock CB, Tanno S, Pegu A, Chen X, Liu C, Koup RA, Mascola JR, Vrbanac VD, Lingwood D, Balazs AB. HIV broadly neutralizing antibody escapability drives the therapeutic efficacy of vectored immunotherapy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.11.603156. [PMID: 39026699 PMCID: PMC11257540 DOI: 10.1101/2024.07.11.603156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Broadly neutralizing antibodies (bNAbs) have shown great promise for prevention and treatment of HIV infection. Breadth of bNAb neutralization, measured in vitro across panels of diverse viral isolates, is often used as a predictor of clinical potential. However, recent prevention studies demonstrate that the clinical efficacy of a broad and potent bNAb (VRC01) is undermined by neutralization resistance of circulating strains. Using HIV-infected humanized mice, we find that therapeutic efficacy of bNAbs delivered as Vectored ImmunoTherapy (VIT) is a function of both the fitness cost and resistance benefit of mutations that emerge during viral escape, which we term 'escapability'. Applying this mechanistic framework, we find that the sequence of the envelope V5-loop alters the resistance benefits of mutants that arise during escape, thereby impacting the therapeutic efficacy of VIT-mediated viral suppression. We also find that an emtricitabine-based antiretroviral drug regimen dramatically enhances the efficacy of VIT, by reducing the fitness of mutants along the escape path. Our findings demonstrate that bNAb escapability is a key determinant to consider in the rational design of antibody regimens with maximal efficacy and illustrates a tractable means of minimizing viral escape from existing bNAbs.
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Affiliation(s)
- Nicolas M.S. Galvez
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Yi Cao
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Adam D. Nitido
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Cailin E. Deal
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Christine L. Boutros
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Scott W. MacDonald
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Yentli E. Soto Albrecht
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Evan C. Lam
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Maegan L. Sheehan
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Dylan Parsons
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Allen Z. Lin
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Martin J. Deymier
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Jacqueline M. Brady
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Benjamin Moon
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Christopher B. Bullock
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Serah Tanno
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Amarendra Pegu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases and National Institutes of Health, Bethesda, MD 20892, USA
| | - Xuejun Chen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases and National Institutes of Health, Bethesda, MD 20892, USA
| | - Cuiping Liu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases and National Institutes of Health, Bethesda, MD 20892, USA
| | - Richard A. Koup
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases and National Institutes of Health, Bethesda, MD 20892, USA
| | - John R. Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases and National Institutes of Health, Bethesda, MD 20892, USA
| | - Vladimir D. Vrbanac
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Daniel Lingwood
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
| | - Alejandro B. Balazs
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, USA
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Baroncini L, Bredl S, Nicole KP, Speck RF. The Humanized Mouse Model: What Added Value Does It Offer for HIV Research? Pathogens 2023; 12:pathogens12040608. [PMID: 37111494 PMCID: PMC10142098 DOI: 10.3390/pathogens12040608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
In the early 2000s, novel humanized mouse models based on the transplantation of human hematopoietic stem and progenitor cells (HSPCs) into immunocompromised mice were introduced (hu mice). The human HSPCs gave rise to a lymphoid system of human origin. The HIV research community has greatly benefitted from these hu mice. Since human immunodeficiency virus (HIV) type 1 infection results in a high-titer disseminated HIV infection, hu mice have been of great value for all types of HIV research from pathogenesis to novel therapies. Since the first description of this new generation of hu mice, great efforts have been expended to improve humanization by creating other immunodeficient mouse models or supplementing mice with human transgenes to improve human engraftment. Many labs have their own customized hu mouse models, making comparisons quite difficult. Here, we discuss the different hu mouse models in the context of specific research questions in order to define which characteristics should be considered when determining which hu mouse model is appropriate for the question posed. We strongly believe that researchers must first define their research question and then determine whether a hu mouse model exists, allowing the research question to be studied.
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Affiliation(s)
- Luca Baroncini
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Simon Bredl
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Kadzioch P Nicole
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Roberto F Speck
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
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3
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Engineering pan-HIV-1 neutralization potency through multispecific antibody avidity. Proc Natl Acad Sci U S A 2022; 119:2112887119. [PMID: 35064083 PMCID: PMC8795538 DOI: 10.1073/pnas.2112887119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2021] [Indexed: 02/08/2023] Open
Abstract
The high genetic diversity of HIV-1 continues to be a major barrier to the development of therapeutics for prevention and treatment. Here, we describe the design of an antibody platform that allows assembly of a highly avid, multispecific molecule that targets, simultaneously, the most conserved epitopes on the HIV-1 envelope glycoprotein. The combined multivalency and multispecificity translates into extraordinary neutralization potency and pan-neutralization of HIV-1 strains, surpassing that of the most potent anti-HIV broadly neutralizing antibody cocktails. Deep mining of B cell repertoires of HIV-1–infected individuals has resulted in the isolation of dozens of HIV-1 broadly neutralizing antibodies (bNAbs). Yet, it remains uncertain whether any such bNAbs alone are sufficiently broad and potent to deploy therapeutically. Here, we engineered HIV-1 bNAbs for their combination on a single multispecific and avid molecule via direct genetic fusion of their Fab fragments to the human apoferritin light chain. The resulting molecule demonstrated a remarkable median IC50 value of 0.0009 µg/mL and 100% neutralization coverage of a broad HIV-1 pseudovirus panel (118 isolates) at a 4 µg/mL cutoff—a 32-fold enhancement in viral neutralization potency compared to a mixture of the corresponding HIV-1 bNAbs. Importantly, Fc incorporation on the molecule and engineering to modulate Fc receptor binding resulted in IgG-like bioavailability in vivo. This robust plug-and-play antibody design is relevant against indications where multispecificity and avidity are leveraged simultaneously to mediate optimal biological activity.
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4
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Weichseldorfer M, Affram Y, Heredia A, Rikhtegaran-Tehrani Z, Sajadi MM, Williams SP, Tagaya Y, Benedetti F, Ramadhani HO, Denaro F, Munawwar A, Bryant J, Zella D, Reitz M, Romerio F, Latinovic OS. Combined cART including Tenofovir Disoproxil, Emtricitabine, and Dolutegravir has potent therapeutic effects in HIV-1 infected humanized mice. J Transl Med 2021; 19:453. [PMID: 34717655 PMCID: PMC8557591 DOI: 10.1186/s12967-021-03120-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/16/2021] [Indexed: 01/17/2023] Open
Abstract
HIV-1 reservoirs persist in the presence of combined antiretroviral therapy (cART). However, cART has transformed HIV-1 infection into a chronic disease marked by control of HIV-1 viral load and mortality reduction. Major challenges remain, including viral resistance upon termination of cART and persistence and identification of tissue distribution of HIV-1 reservoirs. Thus, appropriate animal models that best mimic HIV-1 pathogenesis are important, and the current study complements our previously published validation of the CD34+ hematopoietic humanized mouse model for this purpose. Here we analyze viral suppression using the recently developed combination of antiretrovirals that include Tenofovir Disoproxil (TDF), Emtricitabine (FTC), and Dolutegravir (DTG), a choice based on recent clinical outcomes showing its improved antiretroviral potency, CD4+ T cell preservation, tolerability, and prevention of viral drug resistance compared to that of previous regimens. We used quantitative Airyscan-based super resolution confocal microscopy of selected mouse tissues. Our data allowed us to identify specific solid tissue reservoirs of human T cells expressing the HIV-1 core protein p24. In particular, lymph node, brain, spleen, and liver were visualized as reservoirs for residual infected cells. Marked reduction of viral replication was evident. Considering that detection and visualization of cryptic sites of HIV-1 infection in tissues are clearly crucial steps towards HIV-1 eradication, appropriate animal models with pseudo-human immune systems are needed. In fact, current studies with humans and non-human primates have limited sample availability at multiple stages of infection and cannot easily analyze the effects of differently administered combined antiretroviral treatments on multiple tissues. That is easier to manage when working with humanized mouse models, although we realize the limitations due to low human cell recovery and thus the number of cells available for thorough and comprehensive analyses. Nonetheless, our data further confirm that the CD34+ humanized mouse model is a potentially useful pre-clinical model to study and improve current anti-HIV-1 therapies.
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Affiliation(s)
- Matthew Weichseldorfer
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Yvonne Affram
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Microbial Pathogenesis and Immunology, University of Texas A and M Health Science Center, Bryan, TX, 77843, USA
| | - Alonso Heredia
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | | | - Mohammad M Sajadi
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Sumiko P Williams
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Yutaka Tagaya
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Francesca Benedetti
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Habib O Ramadhani
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Frank Denaro
- Morgan State University, College of Bio Sciences, Baltimore, MD, 21011, USA
| | - Arshi Munawwar
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Joseph Bryant
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Davide Zella
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Marvin Reitz
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Fabio Romerio
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.,Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21201, USA
| | - Olga S Latinovic
- Institute of Human Virology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA. .,Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.
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5
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Walsh SR, Seaman MS. Broadly Neutralizing Antibodies for HIV-1 Prevention. Front Immunol 2021; 12:712122. [PMID: 34354713 PMCID: PMC8329589 DOI: 10.3389/fimmu.2021.712122] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/05/2021] [Indexed: 01/12/2023] Open
Abstract
Given the absence of an effective vaccine for protection against HIV-1 infection, passive immunization strategies that utilize potent broadly neutralizing antibodies (bnAbs) to block acquisition of HIV-1 are being rigorously pursued in the clinical setting. bnAbs have demonstrated robust protection in preclinical animal models, and several leading bnAb candidates have shown favorable safety and pharmacokinetic profiles when tested individually or in combinations in early phase human clinical trials. Furthermore, passive administration of bnAbs in HIV-1 infected individuals has resulted in prolonged suppression of viral rebound following interruption of combination antiretroviral therapy, and robust antiviral activity when administered to viremic individuals. Recent results from the first efficacy trials testing repeated intravenous administrations of the anti-CD4 binding site bnAb VRC01 have demonstrated positive proof of concept that bnAb passive immunization can confer protection against HIV-1 infection in humans, but have also highlighted the considerable barriers that remain for such strategies to effectively contribute to control of the epidemic. In this review, we discuss the current status of clinical studies evaluating bnAbs for HIV-1 prevention, highlight lessons learned from the recent Antibody Mediated Prevention (AMP) efficacy trials, and provide an overview of strategies being employed to improve the breadth, potency, and durability of antiviral protection.
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Affiliation(s)
- Stephen R Walsh
- Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
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6
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Spencer DA, Shapiro MB, Haigwood NL, Hessell AJ. Advancing HIV Broadly Neutralizing Antibodies: From Discovery to the Clinic. Front Public Health 2021; 9:690017. [PMID: 34123998 PMCID: PMC8187619 DOI: 10.3389/fpubh.2021.690017] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/27/2021] [Indexed: 12/15/2022] Open
Abstract
Despite substantial progress in confronting the global HIV-1 epidemic since its inception in the 1980s, better approaches for both treatment and prevention will be necessary to end the epidemic and remain a top public health priority. Antiretroviral therapy (ART) has been effective in extending lives, but at a cost of lifelong adherence to treatment. Broadly neutralizing antibodies (bNAbs) are directed to conserved regions of the HIV-1 envelope glycoprotein trimer (Env) and can block infection if present at the time of viral exposure. The therapeutic application of bNAbs holds great promise, and progress is being made toward their development for widespread clinical use. Compared to the current standard of care of small molecule-based ART, bNAbs offer: (1) reduced toxicity; (2) the advantages of extended half-lives that would bypass daily dosing requirements; and (3) the potential to incorporate a wider immune response through Fc signaling. Recent advances in discovery technology can enable system-wide mining of the immunoglobulin repertoire and will continue to accelerate isolation of next generation potent bNAbs. Passive transfer studies in pre-clinical models and clinical trials have demonstrated the utility of bNAbs in blocking or limiting transmission and achieving viral suppression. These studies have helped to define the window of opportunity for optimal intervention to achieve viral clearance, either using bNAbs alone or in combination with ART. None of these advances with bNAbs would be possible without technological advancements and expanding the cohorts of donor participation. Together these elements fueled the remarkable growth in bNAb development. Here, we review the development of bNAbs as therapies for HIV-1, exploring advances in discovery, insights from animal models and early clinical trials, and innovations to optimize their clinical potential through efforts to extend half-life, maximize the contribution of Fc effector functions, preclude escape through multiepitope targeting, and the potential for sustained delivery.
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Affiliation(s)
- David A. Spencer
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, United States
| | - Mariya B. Shapiro
- Molecular Microbiology & Immunology Department, School of Medicine, Oregon Health & Science University, Portland, OR, United States
| | - Nancy L. Haigwood
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, United States
- Molecular Microbiology & Immunology Department, School of Medicine, Oregon Health & Science University, Portland, OR, United States
| | - Ann J. Hessell
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, United States
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7
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Julg B, Barouch D. Broadly neutralizing antibodies for HIV-1 prevention and therapy. Semin Immunol 2021; 51:101475. [PMID: 33858765 DOI: 10.1016/j.smim.2021.101475] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 03/25/2021] [Indexed: 12/21/2022]
Abstract
Despite immense progress in our ability to prevent and treat HIV-1 infection, HIV-1 remains an incurable disease and a highly efficacious HIV-1 vaccine is not yet available. Additional tools to prevent and treat HIV-1 are therefore necessary. The identification of potent and broadly neutralizing antibodies (bNAbs) against HIV-1 has revolutionized the field and may prove clinically useful. Significant advances have been made in identifying broader and more potent antibodies, characterizing antibodies in preclinical animal models, engineering antibodies to extend half-life and expand breadth and functionality, and evaluating the efficacy of single bNAbs and bNAb combinations in people with and without HIV-1. Here, we review recent progress in developing bNAbs for the prevention and treatment of HIV-1.
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Affiliation(s)
- Boris Julg
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, 02139, USA; Beth Israel Deaconess Medical Center, Boston, MA, 02115, USA.
| | - Dan Barouch
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, 02139, USA; Beth Israel Deaconess Medical Center, Boston, MA, 02115, USA.
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8
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CD34T+ Humanized Mouse Model to Study Mucosal HIV-1 Transmission and Prevention. Vaccines (Basel) 2021; 9:vaccines9030198. [PMID: 33673566 PMCID: PMC7997265 DOI: 10.3390/vaccines9030198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 02/01/2023] Open
Abstract
Humanized mice are critical for HIV-1 research, but humanized mice generated from cord blood are inefficient at mucosal HIV-1 transmission. Most mucosal HIV-1 transmission studies in mice require fetal tissue-engraftment, the use of which is highly restricted or prohibited. We present a fetal tissue-independent model called CD34T+ with enhanced human leukocyte levels in the blood and improved T cell homing to the gut-associated lymphoid tissue. CD34T+ mice are highly permissive to intra-rectal HIV-1 infection and also show normal env diversification in vivo despite high viral replication. Moreover, mucosal infection in CD34T+ mice can be prevented by infusion of broadly neutralizing antibodies. CD34T+ mice can be rapidly and easily generated using only cord blood cells and do not require any complicated surgical procedures for the humanization process. Therefore, CD34T+ mice provide a novel platform for mucosal HIV-1 transmission studies as well as rapid in vivo testing of novel prevention molecules against HIV-1.
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9
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HIV-1 Envelope Glycosylation and the Signal Peptide. Vaccines (Basel) 2021; 9:vaccines9020176. [PMID: 33669676 PMCID: PMC7922494 DOI: 10.3390/vaccines9020176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/07/2021] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
The RV144 trial represents the only vaccine trial to demonstrate any protective effect against HIV-1 infection. While the reason(s) for this protection are still being evaluated, it serves as justification for widespread efforts aimed at developing new, more effective HIV-1 vaccines. Advances in our knowledge of HIV-1 immunogens and host antibody responses to these immunogens are crucial to informing vaccine design. While the envelope (Env) protein is the only viral protein present on the surface of virions, it exists in a complex trimeric conformation and is decorated with an array of variable N-linked glycans, making it an important but difficult target for vaccine design. Thus far, efforts to elicit a protective humoral immune response using structural mimics of native Env trimers have been unsuccessful. Notably, the aforementioned N-linked glycans serve as a component of many of the epitopes crucial for the induction of potentially protective broadly neutralizing antibodies (bnAbs). Thus, a greater understanding of Env structural determinants, most critically Env glycosylation, will no doubt be of importance in generating effective immunogens. Recent studies have identified the HIV-1 Env signal peptide (SP) as an important contributor to Env glycosylation. Further investigation into the mechanisms by which the SP directs glycosylation will be important, both in the context of understanding HIV-1 biology and in order to inform HIV-1 vaccine design.
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10
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van der Velden YU, Villaudy J, Siteur-van Rijnstra E, van der Linden CA, Vink MA, Schermer EE, Weijer K, Berkhout B, Sanders RW, van Gils MJ. Diverse HIV-1 escape pathways from broadly neutralizing antibody PGDM1400 in humanized mice. MAbs 2020; 12:1845908. [PMID: 33218286 PMCID: PMC7755169 DOI: 10.1080/19420862.2020.1845908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Recent studies have shown the potential of broadly neutralizing antibodies (bnAbs) for HIV-1 treatment. One of the candidate antibodies moving into clinical trials is the bnAb PGDM1400. Here, we studied the therapeutic potency and escape pathways of bnAb PGDM1400 during monovalent therapy in human immune system (HIS) mice using the BG505, REJO, MJ4 and AMC008 virus isolates. PGDM1400 administered during chronic infection caused a modest decrease in viral load in the first week of administration in 7 out of 10 animals, which correlated with the in vitro neutralization sensitivity of the viruses to PGDM1400. As expected for monotherapy, viral loads rebounded after about a week and different viral escape pathways were observed, involving the deletion of glycans in the envelope glycoprotein at positions 130 or 160. (Pre)clinical trials should reveal whether PGDM1400 is a useful component of an antibody combination treatment or as part of a tri-specific antibody.
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Affiliation(s)
- Yme U van der Velden
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
| | - Julien Villaudy
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands.,AIMM Therapeutics , Amsterdam, the Netherlands
| | | | - Cynthia A van der Linden
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands.,HIS mouse facility, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
| | - Monique A Vink
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
| | - Edith E Schermer
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
| | - Kees Weijer
- HIS mouse facility, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
| | - Ben Berkhout
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
| | - Rogier W Sanders
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands.,Department of Microbiology and Immunology, Weill Medical College of Cornell University , New York, NY, USA
| | - Marit J van Gils
- Department of Medical Microbiology, Amsterdam UMC, AMC, University of Amsterdam , Amsterdam, the Netherlands
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11
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Ng'uni T, Chasara C, Ndhlovu ZM. Major Scientific Hurdles in HIV Vaccine Development: Historical Perspective and Future Directions. Front Immunol 2020; 11:590780. [PMID: 33193428 PMCID: PMC7655734 DOI: 10.3389/fimmu.2020.590780] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022] Open
Abstract
Following the discovery of HIV as a causative agent of AIDS, the expectation was to rapidly develop a vaccine; but thirty years later, we still do not have a licensed vaccine. Progress has been hindered by the extensive genetic variability of HIV and our limited understanding of immune responses required to protect against HIV acquisition. Nonetheless, valuable knowledge accrued from numerous basic and translational science research studies and vaccine trials has provided insight into the structural biology of the virus, immunogen design and novel vaccine delivery systems that will likely constitute an effective vaccine. Furthermore, stakeholders now appreciate the daunting scientific challenges of developing an effective HIV vaccine, hence the increased advocacy for collaborative efforts among academic research scientists, governments, pharmaceutical industry, philanthropy, and regulatory entities. In this review, we highlight the history of HIV vaccine development efforts, highlighting major challenges and future directions.
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Affiliation(s)
- Tiza Ng'uni
- KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Caroline Chasara
- KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Zaza M Ndhlovu
- KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Cambridge, MA, United States
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12
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Abstract
PURPOSE OF REVIEW In the absence of a protective vaccine against HIV-1, passive immunization using novel broadly neutralizing antibodies (bNAbs) is an attractive concept for HIV-1 prevention. Here, we summarize the results of preclinical and clinical studies of bNAbs, discuss strategies for optimizing bNAb efficacy and lay out current pathways for the development of bNAbs as prophylaxis. RECENT FINDINGS Passive transfer of second-generation bNAbs results inpotent protection against infection in preclinical animal models. Furthermore, multiple bNAbs targeting different epitopes on the HIV-1 envelope trimer are in clinical evaluation and have demonstrated favorable safety profiles and robust antiviral activity in chronically infected individuals. The confirmation that passive immunization with bNAb(s) will prevent HIV-1 acquisition in humans is pending and the focus of ongoing investigations. Given the global diversity of HIV-1, bNAb combinations or multispecific antibodies will most likely be required to produce the necessary breadth for effective protection. SUMMARY Encouraging results from preclinical and clinical studies support the development of bNAbs for prevention and a number of antibodies with exceptional breadth and potency are available for clinical evaluation. Further optimization of viral coverage and antibody half-life will accelerate the clinical implementation of bNAbs as a critical tool for HIV-1 prevention strategies.
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13
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Hariharan V, Kane RS. Glycosylation as a tool for rational vaccine design. Biotechnol Bioeng 2020; 117:2556-2570. [PMID: 32330286 DOI: 10.1002/bit.27361] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 04/01/2020] [Accepted: 04/22/2020] [Indexed: 12/31/2022]
Abstract
The discovery of broadly neutralizing antibodies that can neutralize multiple strains or subtypes of a pathogen has renewed interest in the development of broadly protective vaccines. To that end, there has been an interest in designing immunofocusing strategies to direct the immune response to specific, conserved regions on antigenic proteins. Modulation of glycosylation is one such immunofocusing strategy; extensive glycosylation is often exploited by pathogens for immune evasion. Masking epitopes on protein immunogens with "self" glycans can also shield the underlying protein surface from humoral immune surveillance. We review recent advances in applying glycosylation as an immunofocusing tool. We also highlight recent interesting work in the HIV-1 field involving the identification and elicitation of broadly neutralizing antibodies that incorporate glycans into their binding epitopes.
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Affiliation(s)
- Vivek Hariharan
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Ravi S Kane
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia
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Moshoette T, Ali SA, Papathanasopoulos MA, Killick MA. Engineering and characterising a novel, highly potent bispecific antibody iMab-CAP256 that targets HIV-1. Retrovirology 2019; 16:31. [PMID: 31703699 PMCID: PMC6842167 DOI: 10.1186/s12977-019-0493-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 10/29/2019] [Indexed: 01/07/2023] Open
Abstract
The existing repertoire of HIV-1 patient derived broadly neutralising antibodies (bNAbs) that target the HIV-1 envelope glycoprotein (Env) present numerous and exciting opportunities for immune-based therapeutic and preventative strategies against HIV-1. Combination antibody therapy is required to ensure greater neutralization coverage and limit Env mediated escape mutations following treatment pressure. Engineered bispecific bNAbs (bibNAbs) assimilate the advantages of combination therapy into a single antibody molecule with several configurations reporting potency enhancement as a result of the increased avidity and simultaneous engagement of targeted epitopes. We report the engineering of a novel bibNAb (iMab-CAP256) comprising the highly potent, CAP256.VRC26.25 bNAb with anticipated extension in neutralization coverage through pairing with the host directed, anti-CD4 antibody, ibalizumab (iMab). Recombinant expression of parental monoclonal antibodies and the iMab-CAP256 bibNAb was performed in HEK293T (Human embryonic kidney 293 T antigen) cells, purified to homogeneity by Protein-A affinity chromatography followed by size exclusion chromatography. Antibody assembly and binding functionality of Fab moieties was confirmed by SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) and ELISA, respectively. Breadth and potency were evaluated against a geographical diverse HIV-1 pseudovirus panel (n = 20). Overall, iMab-CAP256 demonstrated an expanded neutralizing coverage, neutralizing single, parental antibody resistant pseudovirus strains and an enhanced neutralization potency against all dual sensitive strains (average fold increase over the more potent parental antibody of 11.4 (range 2 to 31.8). Potency enhancement was not observed for the parental antibody combination treatment (iMab + CAP256) suggesting the presence of a synergistic relationship between the CAP256 and iMab paratope combination in this bibNAb configuration. In addition, iMab-CAP256 bibNAbs exhibited comparable efficacy to other bibNAbs PG9-iMab and 10E08-iMab previously reported in the literature. The enhanced neutralization coverage and potency of iMAb-CAP256 over the parental bNAbs should facilitate superior clinical performance as a therapeutic or preventative strategy against HIV-1.
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Affiliation(s)
- Tumelo Moshoette
- HIV Pathogenesis Research Unit, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Stuart Alvaro Ali
- HIV Pathogenesis Research Unit, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Maria Antonia Papathanasopoulos
- HIV Pathogenesis Research Unit, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Mark Andrew Killick
- HIV Pathogenesis Research Unit, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa.
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15
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Seabright GE, Doores KJ, Burton DR, Crispin M. Protein and Glycan Mimicry in HIV Vaccine Design. J Mol Biol 2019; 431:2223-2247. [PMID: 31028779 PMCID: PMC6556556 DOI: 10.1016/j.jmb.2019.04.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/12/2019] [Accepted: 04/13/2019] [Indexed: 01/30/2023]
Abstract
Antigenic mimicry is a fundamental tenet of structure-based vaccinology. Vaccine strategies for the human immunodeficiency virus type 1 (HIV-1) focus on the mimicry of its envelope spike (Env) due to its exposed location on the viral membrane and role in mediating infection. However, the virus has evolved to minimize the immunogenicity of conserved epitopes on the envelope spike. This principle is starkly illustrated by the presence of an extensive array of host-derived glycans, which act to shield the underlying protein from antibody recognition. Despite these hurdles, a subset of HIV-infected individuals eventually develop broadly neutralizing antibodies that recognize these virally presented glycans. Effective HIV-1 immunogens are therefore likely to involve some degree of mimicry of both the protein and glycan components of Env. As such, considerable efforts have been made to characterize the structure of the envelope spike and its glycan shield. This review summarizes the recent progress made in this field, with an emphasis on our growing understanding of the factors shaping the glycan shield of Env derived from both virus and soluble immunogens. We argue that recombinant mimics of the envelope spike are currently capable of capturing many features of the native viral glycan shield. Finally, we explore strategies through which the immunogenicity of Env glycans may be enhanced in the development of future immunogens.
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Affiliation(s)
- Gemma E Seabright
- Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK; School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Katie J Doores
- Department of Infectious Diseases, King's College London, Guy's Hospital, London, SE1 9RT, UK
| | - Dennis R Burton
- Department of Immunology and Microbiology, the Scripps Centre for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), International AIDS Vaccine Initiative Neutralizing Antibody Centre, Scripps Research, La Jolla, CA 92037, USA
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK; Department of Immunology and Microbiology, the Scripps Centre for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), International AIDS Vaccine Initiative Neutralizing Antibody Centre, Scripps Research, La Jolla, CA 92037, USA.
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16
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Anti-HIV-1 antibody-dependent cellular cytotoxicity: is there more to antibodies than neutralization? Curr Opin HIV AIDS 2019; 13:160-166. [PMID: 29194123 DOI: 10.1097/coh.0000000000000439] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE OF REVIEW An increasing body of evidence suggests that nonneutralizing Fc effector functions including antibody-dependent cellular cytotoxicity (ADCC) contribute to protection against HIV-1 acquisition. We discuss recent advances in anti-HIV-1 ADCC research with a particular focus on ADCC mediated by Env-specific antibodies in vitro and in vivo, the curative potential of HIV-1-specific ADCC antibodies and the mechanisms of HIV-1 resistance to ADCC. RECENT FINDINGS ADCC activities of broadly neutralizing and nonneutralizing monoclonal antibody panels were recently characterized in vitro against several lab-adapted and primary isolates of HIV-1. ADCC activity of these monoclonal antibodies generally correlated with binding to infected cells and were greater against the lab-adapted strains compared with primary HIV-1 isolates. Several recent studies in mouse and macaque models of HIV-1 infection suggest Fc-mediated effector functions contribute to the protective efficacy of broadly neutralizing antibodies and exert immune pressure on HIV-1 in vivo. SUMMARY An increasing body of evidence suggests that ADCC-mediating antibodies, particularly when combined with neutralizing functions, can facilitate prevention and control of HIV-1. The precise mechanisms of partial protection conferred by nonneutralizing antibodies in vivo remain unclear and will need to be fully investigated in order to realize their full potential for HIV-1 vaccines.
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17
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Rochat MA, Schlaepfer E, Kuster SP, Li D, Audige A, Ivic S, Fahrny A, Speck RF. Monitoring HIV DNA and cellular activation markers in HIV-infected humanized mice under cART. Virol J 2018; 15:191. [PMID: 30558630 PMCID: PMC6296118 DOI: 10.1186/s12985-018-1101-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/27/2018] [Indexed: 12/22/2022] Open
Abstract
Background The major obstacle to cure of HIV type-1 infection is the presence of the HIV reservoir, hidden from the immune system and insensitive to combined antiretroviral therapy (cART). Eradication approaches have been hindered by the difficulty for accurately monitoring its size in vivo, especially in the lymphoid organs. Humanized mouse models are a valuable tool for systematically assess the efficacy of therapeutic interventions in reducing the HIV reservoir. Nonetheless, persistence of the HIV reservoir over time, in the presence of cART, has yet to be analyzed in this in vivo model. Findings We found that the proviral DNA as well as the total DNA were very stable in the spleen and mesenteric lymph node irrespective of the length of cART. Notably, the amount of proviral DNA was very similar in the spleen and lymph node. Furthermore, we observed a correlation between the percentage of splenic human CD4+ T-cells with total HIV DNA, between the number of human CD38 + CD8+ T-cells in the spleen with the amount of integrated HIV DNA, and eventually between the hCD4/hCD8 ratio in the spleen with integrated as well as total HIV DNA implying that the CD8+ T cells influence the size of the HIV reservoir. Conclusions Here, we demonstrated the stability of this reservoir in humanized mice irrespective of the length of cART, confirming the relevancy of this model for HIV latency eradication investigations. Notably, we also found correlates between the frequency of CD4+ T-cells, their activation status and viral parameters, which were analogous to the ones in HIV-infected patients. Thus, hu-mice represent a very valuable HIV latency model.
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Affiliation(s)
- Mary-Aude Rochat
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Erika Schlaepfer
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Stefan P Kuster
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Duo Li
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Annette Audige
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Sandra Ivic
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Audrey Fahrny
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Roberto F Speck
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
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18
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Gruell H, Klein F. Antibody-mediated prevention and treatment of HIV-1 infection. Retrovirology 2018; 15:73. [PMID: 30445968 PMCID: PMC6240265 DOI: 10.1186/s12977-018-0455-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/30/2018] [Indexed: 01/11/2023] Open
Abstract
Novel broadly neutralizing antibodies targeting HIV-1 hold promise for their use in the prevention and treatment of HIV-1 infection. Pre-clinical results have encouraged the evaluation of these antibodies in healthy and HIV-1-infected humans. In first clinical trials, highly potent broadly neutralizing antibodies have demonstrated their safety and significant antiviral activity by reducing viremia and delaying the time to viral rebound in individuals interrupting antiretroviral therapy. While emerging antibody-resistant viral variants have indicated limitations of antibody monotherapy, strategies to enhance the efficacy of broadly neutralizing antibodies in humans are under investigation. These include the use of antibody combinations to prevent viral escape, antibody modifications to increase the half-life and the co-administration of latency-reversing agents to target the cellular reservoir of HIV-1. We provide an overview of the results of pre-clinical and clinical studies of broadly HIV-1 neutralizing antibodies, discuss their implications and highlight approaches for the ongoing advancement into humans.
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Affiliation(s)
- Henning Gruell
- Laboratory of Experimental Immunology, Institute of Virology, University Hospital Cologne, Fürst-Pückler-Str. 56, 50935 Cologne, Germany
- German Center for Infection Research, Partner-Site Bonn-Cologne, Cologne, Germany
| | - Florian Klein
- Laboratory of Experimental Immunology, Institute of Virology, University Hospital Cologne, Fürst-Pückler-Str. 56, 50935 Cologne, Germany
- German Center for Infection Research, Partner-Site Bonn-Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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19
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Kuhlmann AS, Haworth KG, Barber-Axthelm IM, Ironside C, Giese MA, Peterson CW, Kiem HP. Long-Term Persistence of Anti-HIV Broadly Neutralizing Antibody-Secreting Hematopoietic Cells in Humanized Mice. Mol Ther 2018; 27:164-177. [PMID: 30391142 DOI: 10.1016/j.ymthe.2018.09.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 09/14/2018] [Accepted: 09/20/2018] [Indexed: 01/12/2023] Open
Abstract
Broadly neutralizing antibodies (bNAbs) are among the most promising strategies to achieve long-term control of HIV-1 in the absence of combination antiretroviral therapy. Passive administration of such antibodies in patients efficiently decreases HIV-1 viremia, but is limited by the serum half-life of the protein. Here, we investigated whether antibody-secreting hematopoietic cells could overcome this problem. We genetically modified human CD34+ hematopoietic stem and progenitor cells (HSPCs) to secrete bNAbs and transplanted them into immunodeficient mice. We found that the gene-modified cells engraft and stably secrete antibodies in the peripheral blood of the animals for the 9 months of the study. Antibodies were predominantly expressed by human HSPC-derived T- and B cells. Importantly, we found that secreted PGT128 was able to delay HIV-1 viremia in vivo and also prevent a decline in CD4+ cells. Gene-modified cells were maintained in bone marrow and were also detected in spleen, thymus, lymph nodes, and gut-associated lymphoid tissue. These data indicate that the bNAb secretion from HSPC-derived cells in mice is functional and can affect viral infection and CD4+ cell maintenance. This study paves the way for potential applications to other diseases requiring long-lasting protein or antibody delivery.
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Affiliation(s)
- Anne-Sophie Kuhlmann
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA
| | - Kevin G Haworth
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA
| | - Isaac M Barber-Axthelm
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA
| | - Christina Ironside
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA
| | - Morgan A Giese
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA
| | - Christopher W Peterson
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA; Department of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Hans-Peter Kiem
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109-1024, USA; Department of Medicine, University of Washington, Seattle, WA, 98195, USA; Department of Pathology, University of Washington, Seattle, WA, 98195, USA.
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20
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van der Velden YU, Villaudy J, Siteur-van Rijnstra E, van der Linden CA, Frankin E, Weijer K, Schermer E, Vink MA, Berkhout B, Sanders RW, van Gils MJ. Short Communication: Protective Efficacy of Broadly Neutralizing Antibody PGDM1400 Against HIV-1 Challenge in Humanized Mice. AIDS Res Hum Retroviruses 2018; 34:790-793. [PMID: 30003812 DOI: 10.1089/aid.2018.0114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Broadly neutralizing antibodies (bNAbs) such as PGDM1400 show promise as prophylactic and therapeutic agents against HIV-1. Human immune system mice were passively immunized with different doses of PGDM1400 and challenged 24 h later with a high dose of HIV-1JRCSF. We found that PGDM1400 provided protection against HIV-1 challenge in a concentration dependent manner and that the protective concentration in blood was ∼75-fold higher than the in vitro 50% inhibitory concentration. The results demonstrate that PGDM1400 might be a promising component of strategies to prevent HIV-1 infection and provide support for the pursuit of vaccines that induce PGDM1400-like bNAbs.
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Affiliation(s)
- Yme U. van der Velden
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Julien Villaudy
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- AIMM Therapeutics, Amsterdam, the Netherlands
| | | | - Cynthia A. van der Linden
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- HIS Mouse Facility, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Esmay Frankin
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Kees Weijer
- HIS Mouse Facility, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Edith Schermer
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Monique A. Vink
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Rogier W. Sanders
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York
| | - Marit J. van Gils
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
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Targeting the HIV-1 Spike and Coreceptor with Bi- and Trispecific Antibodies for Single-Component Broad Inhibition of Entry. J Virol 2018; 92:JVI.00384-18. [PMID: 29976677 DOI: 10.1128/jvi.00384-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/29/2018] [Indexed: 12/15/2022] Open
Abstract
Protection against acquiring human immunodeficiency virus (HIV) infection may not require a vaccine in the conventional sense, because broadly neutralizing antibodies (bNAbs) alone prevent HIV infection in relevant animal challenge models. Additionally, bNAbs as therapeutics can effectively suppress HIV replication in infected humans and in animal models. Combinations of bNAbs are generally even more effective, and bNAb-derived multivalent antibody-like molecules also inhibit HIV replication both in vitro and in vivo To expand the available array of multispecific HIV inhibitors, we designed single-component molecules that incorporate two (bispecific) or three (trispecific) bNAbs that recognize HIV Env exclusively, a bispecific CrossMAb targeting two epitopes on the major HIV coreceptor, CCR5, and bi- and trispecifics that cross-target both Env and CCR5. These newly designed molecules displayed exceptional breadth, neutralizing 98 to 100% of a 109-virus panel, as well as additivity and potency compared to those of the individual parental control IgGs. The bispecific molecules, designed as tandem single-chain variable fragments (scFvs) (10E8fv-N6fv and m36.4-PRO 140fv), displayed median 50% inhibitory concentration (IC50s) of 0.0685 and 0.0131 μg/ml, respectively. A trispecific containing 10E8-PGT121-PGDM1400 Env-specific binding sites was equally potent (median IC50 of 0.0135 μg/ml), while a trispecific molecule targeting Env and CCR5 simultaneously (10E8Fab-PGDM1400fv-PRO 140fv) demonstrated even greater potency, with a median IC50 of 0.007 μg/ml. By design, some of these molecules lacked Fc-mediated effector function; therefore, we also constructed a trispecific prototype possessing reconstituted CH2-CH3 domains to restore Fc receptor binding capacity. The molecules developed here, along with those described previously, possess promise as prophylactic and therapeutic agents against HIV.IMPORTANCE Broadly neutralizing antibodies (bNAbs) prevent HIV infection in monkey challenge models and suppress HIV replication in infected humans. Combinations of bNAbs are more effective at suppression, and antibody-like molecules engineered to have two or three bNAb combining sites also inhibit HIV replication in monkeys and other animal models. To expand the available array of multispecific HIV inhibitors, we designed single-component molecules that incorporate two (bispecific) or three (trispecific) bNAb binding sites that recognize the HIV envelope glycoprotein (Env) or the HIV coreceptor (CCR5) or that cross-target both Env and CCR5. Several of the bi- and trispecific molecules neutralized most viruses in a diverse cross-clade panel, with greater breadth and potency than those of the individual parental bNAbs. The molecules described here provide additional options for preventing or suppressing HIV infection.
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22
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Humanized mouse models to study pathophysiology and treatment of HIV infection. Curr Opin HIV AIDS 2018; 13:143-151. [DOI: 10.1097/coh.0000000000000440] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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23
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Huckaby JT, Lai SK. PEGylation for enhancing nanoparticle diffusion in mucus. Adv Drug Deliv Rev 2018; 124:125-139. [PMID: 28882703 DOI: 10.1016/j.addr.2017.08.010] [Citation(s) in RCA: 242] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 02/07/2023]
Abstract
The viscoelastic mucus secretions coating exposed organs such as the lung airways and the female reproductive tract can trap and quickly eliminate not only foreign pathogens and ultrafine particles but also particle-based drug delivery systems, thus limiting sustained and targeted drug delivery at mucosal surfaces. To improve particle distribution across the mucosa and enhance delivery to the underlying epithelium, many investigators have sought to develop nanoparticles capable of readily traversing mucus. The first synthetic nanoparticles shown capable of rapidly penetrating physiological mucus secretions utilized a dense coating of polyethylene glycol (PEG) covalently grafted onto the surface of preformed polymeric nanoparticles. In the decade since, PEG has become the gold standard in engineering mucus-penetrating drug carriers for sustained and targeted drug delivery to the lungs, gastrointestinal tract, eyes, and female reproductive tract. This review summarizes the history of the development of various PEG-based mucus-penetrating particles, and highlights the key physicochemical properties of PEG coatings and PEGylation strategies to achieve muco-inert PEG coatings on nanoparticle drug carriers for improved drug and gene delivery at mucosal surfaces.
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24
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Hua CK, Ackerman ME. Increasing the Clinical Potential and Applications of Anti-HIV Antibodies. Front Immunol 2017; 8:1655. [PMID: 29234320 PMCID: PMC5712301 DOI: 10.3389/fimmu.2017.01655] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/13/2017] [Indexed: 01/03/2023] Open
Abstract
Preclinical and early human clinical studies of broadly neutralizing antibodies (bNAbs) to prevent and treat HIV infection support the clinical utility and potential of bNAbs for prevention, postexposure prophylaxis, and treatment of acute and chronic infection. Observed and potential limitations of bNAbs from these recent studies include the selection of resistant viral populations, immunogenicity resulting in the development of antidrug (Ab) responses, and the potentially toxic elimination of reservoir cells in regeneration-limited tissues. Here, we review opportunities to improve the clinical utility of HIV Abs to address these challenges and further accomplish functional targets for anti-HIV Ab therapy at various stages of exposure/infection. Before exposure, bNAbs' ability to serve as prophylaxis by neutralization may be improved by increasing serum half-life to necessitate less frequent administration, delivering genes for durable in vivo expression, and targeting bNAbs to sites of exposure. After exposure and/or in the setting of acute infection, bNAb use to prevent/reduce viral reservoir establishment and spread may be enhanced by increasing the potency with which autologous adaptive immune responses are stimulated, clearing acutely infected cells, and preventing cell-cell transmission of virus. In the setting of chronic infection, bNAbs may better mediate viral remission or "cure" in combination with antiretroviral therapy and/or latency reversing agents, by targeting additional markers of tissue reservoirs or infected cell types, or by serving as targeting moieties in engineered cell therapy. While the clinical use of HIV Abs has never been closer, remaining studies to precisely define, model, and understand the complex roles and dynamics of HIV Abs and viral evolution in the context of the human immune system and anatomical compartmentalization will be critical to both optimize their clinical use in combination with existing agents and define further strategies with which to enhance their clinical safety and efficacy.
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Affiliation(s)
- Casey K. Hua
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH, United States
| | - Margaret E. Ackerman
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH, United States
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
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25
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Kim J, Peachman KK, Jobe O, Morrison EB, Allam A, Jagodzinski L, Casares SA, Rao M. Tracking Human Immunodeficiency Virus-1 Infection in the Humanized DRAG Mouse Model. Front Immunol 2017; 8:1405. [PMID: 29163484 PMCID: PMC5663722 DOI: 10.3389/fimmu.2017.01405] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/11/2017] [Indexed: 11/23/2022] Open
Abstract
Humanized mice are emerging as an alternative model system to well-established non-human primate (NHP) models for studying human immunodeficiency virus (HIV)-1 biology and pathogenesis. Although both NHP and humanized mice have their own strengths and could never truly reflect the complex human immune system and biology, there are several advantages of using the humanized mice in terms of using primary HIV-1 for infection instead of simian immunodeficiency virus or chimera simian/HIV. Several different types of humanized mice have been developed with varying levels of reconstitution of human CD45+ cells. In this study, we utilized humanized Rag1KO.IL2RγcKO.NOD mice expressing HLA class II (DR4) molecule (DRAG mice) infused with HLA-matched hematopoietic stem cells from umbilical cord blood to study early events after HIV-1 infection, since the mucosal tissues of these mice are highly enriched for human lymphocytes and express the receptors and coreceptors needed for HIV-1 entry. We examined the various tissues on days 4, 7, 14, and 21 after an intravaginal administration of a single dose of purified primary HIV-1. Plasma HIV-1 RNA was detected as early as day 7, with 100% of the animals becoming plasma RNA positive by day 21 post-infection. Single cells were isolated from lymph nodes, bone marrow, spleen, gut, female reproductive tissue, and brain and analyzed for gag RNA and strong stop DNA by quantitative (RT)-PCR. Our data demonstrated the presence of HIV-1 viral RNA and DNA in all of the tissues examined and that the virus was replication competent and spread rapidly. Bone marrow, gut, and lymph nodes were viral RNA positive by day 4 post-infection, while other tissues and plasma became positive typically between 7 and 14 days post-infection. Interestingly, the brain was the last tissue to become HIV-1 viral RNA and DNA positive by day 21 post-infection. These data support the notion that humanized DRAG mice could serve as an excellent model for studying the trafficking of HIV-1 to the various tissues, identification of cells harboring the virus, and thus could serve as a model system for HIV-1 pathogenesis and reservoir studies.
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Affiliation(s)
- Jiae Kim
- United States Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Laboratory of Adjuvant and Antigen Research, United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Kristina K Peachman
- United States Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Laboratory of Adjuvant and Antigen Research, United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Ousman Jobe
- United States Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Laboratory of Adjuvant and Antigen Research, United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Elaine B Morrison
- Laboratory of Adjuvant and Antigen Research, United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Atef Allam
- United States Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Laboratory of Adjuvant and Antigen Research, United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Linda Jagodzinski
- United States Military HIV Research Program, Department of Laboratory Diagnostics and Monitoring, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Sofia A Casares
- United States Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, MD, United States
| | - Mangala Rao
- Laboratory of Adjuvant and Antigen Research, United States Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
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26
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Pegu A, Hessell AJ, Mascola JR, Haigwood NL. Use of broadly neutralizing antibodies for HIV-1 prevention. Immunol Rev 2017; 275:296-312. [PMID: 28133803 DOI: 10.1111/imr.12511] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antibodies have a long history in antiviral therapy, but until recently, they have not been actively pursued for HIV-1 due to modest potency and breadth of early human monoclonal antibodies (MAbs) and perceived insurmountable technical, financial, and logistical hurdles. Recent advances in the identification and characterization of MAbs with the ability to potently neutralize diverse HIV-1 isolates have reinvigorated discussion and testing of these products in humans, since new broadly neutralizing MAbs (bnMAbs) are more likely to be effective against worldwide strains of HIV-1. In animal models, there is abundant evidence that bnMAbs can block infection in a dose-dependent manner, and the more potent bnMAbs will allow clinical testing at infusion doses that are practically achievable. Moreover, recent advances in antibody engineering are providing further improvements in MAb potency, breadth, and half-life. This review summarizes the current state of the field of bnMAb protection in animal models as well as a review of variables that are critical for antiviral activity. Several bnMAbs are currently in clinical testing, and we offer perspectives on their use as pre-exposure prophylaxis (PrEP), potential benefits beyond sterilizing immunity, and a discussion of future approaches to engineer novel molecules.
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Affiliation(s)
| | - Ann J Hessell
- Oregon National Primate Center, Oregon Health & Science University, Beaverton, OR, USA
| | | | - Nancy L Haigwood
- Oregon National Primate Center, Oregon Health & Science University, Beaverton, OR, USA
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Abstract
Human immunodeficiency virus (HIV) remains a significant source of morbidity and mortality worldwide. No effective vaccine is available to prevent HIV transmission, and although antiretroviral therapy can prevent disease progression, it does not cure HIV infection. Substantial effort is therefore currently directed toward basic research on HIV pathogenesis and persistence and developing methods to stop the spread of the HIV epidemic and cure those individuals already infected with HIV. Humanized mice are versatile tools for the study of HIV and its interaction with the human immune system. These models generally consist of immunodeficient mice transplanted with human cells or reconstituted with a near-complete human immune system. Here, we describe the major humanized mouse models currently in use, and some recent advances that have been made in HIV research/therapeutics using these models.
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Affiliation(s)
- Matthew D Marsden
- Department of Medicine, Division of Hematology and Oncology, University of California, Los Angeles, California 90095;
| | - Jerome A Zack
- Department of Medicine, Division of Hematology and Oncology, University of California, Los Angeles, California 90095; .,Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095;
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Abstract
PURPOSE OF REVIEW Recent discoveries of highly potent broadly HIV-1 neutralizing antibodies provide new opportunities to successfully prevent, treat, and potentially cure HIV-1 infection. To test their activity in vivo, humanized mice have been shown to be a powerful model and were used to investigate antibody-mediated prevention and therapy approaches. In this review, we will summarize recent findings in humanized mice that have informed on the potential use of broadly neutralizing antibodies targeting HIV-1 in humans. RECENT FINDINGS Humanized mouse models have been used to demonstrate the antiviral efficacy of HIV-1 neutralizing antibodies in vivo. It has been shown that a combination of antibodies can suppress viremia below the limit of detection and targets the HIV-1 reservoir. Moreover, passively administered antibodies and vector-mediated antibody production protect humanized mice from HIV-1 infection. Finally, immunization studies in knock-in/transgenic mice carrying human antibody gene segments have informed on potential vaccination strategies to induce broad and potent HIV-1 neutralizing antibodies. SUMMARY Humanized mouse models are of great value for HIV-1 research. They represent a highly versatile in vivo system to investigate novel approaches for HIV-1 prevention and therapy and expedite the critical translation from basic findings to clinical application.
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Brandenberg OF, Magnus C, Rusert P, Günthard HF, Regoes RR, Trkola A. Predicting HIV-1 transmission and antibody neutralization efficacy in vivo from stoichiometric parameters. PLoS Pathog 2017; 13:e1006313. [PMID: 28472201 PMCID: PMC5417720 DOI: 10.1371/journal.ppat.1006313] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/24/2017] [Indexed: 01/08/2023] Open
Abstract
The potential of broadly neutralizing antibodies targeting the HIV-1 envelope trimer to prevent HIV-1 transmission has opened new avenues for therapies and vaccines. However, their implementation remains challenging and would profit from a deepened mechanistic understanding of HIV-antibody interactions and the mucosal transmission process. In this study we experimentally determined stoichiometric parameters of the HIV-1 trimer-antibody interaction, confirming that binding of one antibody is sufficient for trimer neutralization. This defines numerical requirements for HIV-1 virion neutralization and thereby enables mathematical modelling of in vitro and in vivo antibody neutralization efficacy. The model we developed accurately predicts antibody efficacy in animal passive immunization studies and provides estimates for protective mucosal antibody concentrations. Furthermore, we derive estimates of the probability for a single virion to start host infection and the risks of male-to-female HIV-1 transmission per sexual intercourse. Our work thereby delivers comprehensive quantitative insights into both the molecular principles governing HIV-antibody interactions and the initial steps of mucosal HIV-1 transmission. These insights, alongside the underlying, adaptable modelling framework presented here, will be valuable for supporting in silico pre-trial planning and post-hoc evaluation of HIV-1 vaccination or antibody treatment trials.
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Affiliation(s)
| | - Carsten Magnus
- Institute of Medical Virology, University of Zürich, Zurich, Switzerland
| | - Peter Rusert
- Institute of Medical Virology, University of Zürich, Zurich, Switzerland
| | - Huldrych F. Günthard
- Institute of Medical Virology, University of Zürich, Zurich, Switzerland
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
| | - Roland R. Regoes
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Alexandra Trkola
- Institute of Medical Virology, University of Zürich, Zurich, Switzerland
- * E-mail:
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30
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Fuchs SP, Desrosiers RC. Promise and problems associated with the use of recombinant AAV for the delivery of anti-HIV antibodies. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:16068. [PMID: 28197421 PMCID: PMC5289440 DOI: 10.1038/mtm.2016.68] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/11/2016] [Indexed: 02/07/2023]
Abstract
Attempts to elicit antibodies with potent neutralizing activity against a broad range of human immunodeficiency virus (HIV) isolates have so far proven unsuccessful. Long-term delivery of monoclonal antibodies (mAbs) with such activity is a creative alternative that circumvents the need for an immune response and has the potential for creating a long-lasting sterilizing barrier against HIV. This approach is made possible by an incredible array of potent broadly neutralizing antibodies (bnAbs) that have been identified over the last several years. Recombinant adeno-associated virus (rAAV) vectors are ideally suited for long-term delivery for a variety of reasons. The only products made from rAAV are derived from the transgenes that are put into it; as long as those products are not viewed as foreign, expression from muscle tissue may continue for decades. Thus, use of rAAV to achieve long-term delivery of anti-HIV mAbs with potent neutralizing activity against a broad range of HIV-1 isolates is emerging as a promising concept for the prevention or treatment of HIV-1 infection in humans. Experiments in mice and monkeys that have demonstrated protective efficacy against AIDS virus infection have raised hopes for the promise of this approach. However, all published experiments in monkeys have encountered unwanted immune responses to the AAV-delivered antibody, and these immune responses appear to limit the levels of delivered antibody that can be achieved. In this review, we highlight the promise of rAAV-mediated antibody delivery for the prevention or treatment of HIV infection in humans, but we also discuss the obstacles that will need to be understood and solved in order for the promise of this approach to be realized.
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Affiliation(s)
- Sebastian P Fuchs
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, USA; Institut für Klinische und Molekulare Virologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ronald C Desrosiers
- Department of Pathology, Miller School of Medicine, University of Miami , Miami, Florida, USA
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