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Marchitto L, Richard J, Prévost J, Tauzin A, Yang D, Chiu TJ, Chen HC, Díaz-Salinas MA, Nayrac M, Benlarbi M, Beaudoin-Bussières G, Anand SP, Dionne K, Bélanger É, Chatterjee D, Medjahed H, Bourassa C, Tolbert WD, Hahn BH, Munro JB, Pazgier M, Smith AB, Finzi A. The combination of three CD4-induced antibodies targeting highly conserved Env regions with a small CD4-mimetic achieves potent ADCC activity. J Virol 2024:e0101624. [PMID: 39248460 DOI: 10.1128/jvi.01016-24] [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: 06/07/2024] [Accepted: 08/13/2024] [Indexed: 09/10/2024] Open
Abstract
The majority of naturally elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs) because they are unable to recognize the Env trimer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have the potential to eliminate HIV-1-infected cells by antibody-dependent cellular cytotoxicity (ADCC) provided that Env is present on the cell surface in its "open" conformation. This is because most nnAbs recognize epitopes that become accessible only after Env interaction with CD4 and the exposure of epitopes that are normally occluded in the closed trimer. HIV-1 limits this vulnerability by downregulating CD4 from the surface of infected cells, thus preventing a premature encounter of Env with CD4. Small CD4-mimetics (CD4mc) sensitize HIV-1-infected cells to ADCC by opening the Env glycoprotein and exposing CD4-induced (CD4i) epitopes. There are two families of CD4i nnAbs, termed anti-cluster A and anti-CoRBS Abs, which are known to mediate ADCC in the presence of CD4mc. Here, we performed Fab competition experiments and found that anti-gp41 cluster I antibodies comprise a major fraction of the plasma ADCC activity in people living with HIV (PLWH). Moreover, addition of gp41 cluster I antibodies to cluster A and CoRBS antibodies greatly enhanced ADCC-mediated cell killing in the presence of a potent indoline CD4mc, CJF-III-288. This cocktail outperformed broadly neutralizing antibodies and even showed activity against HIV-1-infected monocyte-derived macrophages. Thus, combining CD4i antibodies with different specificities achieves maximal ADCC activity, which may be of utility in HIV cure strategies.IMPORTANCEThe elimination of HIV-1-infected cells remains an important medical goal. Although current antiretroviral therapy decreases viral loads below detection levels, it does not eliminate latently infected cells that form the viral reservoir. Here, we developed a cocktail of non-neutralizing antibodies targeting highly conserved Env regions and combined it with a potent indoline CD4mc. This combination exhibited potent ADCC activity against HIV-1-infected primary CD4 + T cells as well as monocyte-derived macrophages, suggesting its potential utility in decreasing the size of the viral reservoir.
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Affiliation(s)
- Lorie Marchitto
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Alexandra Tauzin
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Derek Yang
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ta-Jung Chiu
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Marco A Díaz-Salinas
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Manon Nayrac
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Mehdi Benlarbi
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Guillaume Beaudoin-Bussières
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Sai Priya Anand
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Katrina Dionne
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Étienne Bélanger
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | | | | | | | - William D Tolbert
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - James B Munro
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Marzena Pazgier
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
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2
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Marchitto L, Richard J, Prévost J, Tauzin A, Yang D, Chiu T, Chen HC, Díaz-Salinas MA, Nayrac M, Benlarbi M, Beaudoin-Bussières G, Anand SP, Dionne K, Bélanger É, Chatterjee D, Medjahed H, Bourassa C, Tolbert WD, Hahn BH, Munro JB, Pazgier M, Smith AB, Finzi A. The combination of three CD4-induced antibodies targeting highly conserved Env regions with a small CD4-mimetic achieves potent ADCC activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597978. [PMID: 38895270 PMCID: PMC11185797 DOI: 10.1101/2024.06.07.597978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
The majority of naturally-elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs), because they are unable to recognize the Env timer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have the potential to eliminate HIV-1-infected cells by Antibody-Dependent Cellular Cytotoxicity (ADCC) provided that Env is present on the cell surface in its "open" conformation. This is because most nnAbs recognize epitopes that become accessible only after Env interaction with CD4 and the exposure of epitopes that are normally occluded in the closed trimer. HIV-1 limits this vulnerability by downregulating CD4 from the surface of infected cells, thus preventing a premature encounter of Env with CD4. Small CD4-mimetics (CD4mc) sensitize HIV-1-infected cells to ADCC by opening the Env glycoprotein and exposing CD4-induced (CD4i) epitopes. There are two families of CD4i nnAbs, termed anti-cluster A and anti-CoRBS Abs, which are known to mediate ADCC in the presence of CD4mc. Here, we performed Fab competition experiments and found that anti-gp41 cluster I antibodies comprise a major fraction of the plasma ADCC activity in people living with HIV (PLWH). Moreover, addition of gp41 cluster I antibodies to cluster A and CoRBS antibodies greatly enhanced ADCC mediated cell killing in the presence of a potent indoline CD4mc, CJF-III-288. This cocktail outperformed broadly-neutralizing antibodies and even showed activity against HIV-1 infected monocyte-derived macrophages. Thus, combining CD4i antibodies with different specificities achieves maximal ADCC activity, which may be of utility in HIV cure strategies.
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Affiliation(s)
- Lorie Marchitto
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | | | - Jérémie Prévost
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Alexandra Tauzin
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Derek Yang
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - TaJung Chiu
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Marco A. Díaz-Salinas
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Manon Nayrac
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Mehdi Benlarbi
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Guillaume Beaudoin-Bussières
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Sai Priya Anand
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Katrina Dionne
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Étienne Bélanger
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Debashree Chatterjee
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | | | | | - William D. Tolbert
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Beatrice H. Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - James B. Munro
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Marzena Pazgier
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Amos B. Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
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Rajendra D, Maroli N, Dixit NM, Maiti PK. Molecular dynamics simulations show how antibodies may rescue HIV-1 mutants incapable of infecting host cells. J Biomol Struct Dyn 2023:1-11. [PMID: 38111161 DOI: 10.1080/07391102.2023.2294835] [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: 08/10/2023] [Accepted: 12/01/2023] [Indexed: 12/20/2023]
Abstract
High mutation and replication rates of HIV-1 result in the continuous generation of variants, allowing it to adapt to changing host environments. Mutations often have deleterious effects, but variants carrying them are rapidly purged. Surprisingly, a particular variant incapable of entering host cells was found to be rescued by host antibodies targeting HIV-1. Understanding the molecular mechanism of this rescue is important to develop and improve antibody-based therapies. To unravel the underlying mechanisms, we performed fully atomistic molecular dynamics simulations of the HIV-1 gp41 trimer responsible for viral entry into host cells, its entry-deficient variant, and its complex with the rescuing antibody. We find that the Q563R mutation, which the entry-deficient variant carries, prevents the native conformation of the gp41 6-helix bundle required for entry and stabilizes an alternative conformation instead. This is the consequence of substantial changes in the secondary structure and interactions between the domains of gp41. Binding of the antibody F240 to gp41 reverses these changes and re-establishes the native conformation, resulting in rescue. To test the generality of this mechanism, we performed simulations with the entry-deficient L565A variant and antibody 3D6. We find that 3D6 binding was able to reverse structural and interaction changes introduced by the mutation and restore the native gp41 conformation. Viral variants may not only escape antibodies but be aided by them in their survival, potentially compromising antibody-based therapies, including vaccination and passive immunization. Our simulation framework could serve as a tool to assess the likelihood of such resistance against specific antibodies.Communicated by Ramaswamy H. SarmaCommunicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Dharanish Rajendra
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bengaluru, India
| | - Nikhil Maroli
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bengaluru, India
| | - Narendra M Dixit
- Department of Chemical Engineering, Indian Institute of Science, Bengaluru, India
- Department of Bioengineering, Indian Institute of Science, Bengaluru, India
| | - Prabal K Maiti
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bengaluru, India
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4
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Klug G, Cole FM, Hicar MD, Watt C, Peters T, Pincus SH. Identification of Anti-gp41 Monoclonal Antibodies That Effectively Target Cytotoxic Immunoconjugates to Cells Infected with Human Immunodeficiency Virus, Type 1. Vaccines (Basel) 2023; 11:vaccines11040829. [PMID: 37112741 PMCID: PMC10144985 DOI: 10.3390/vaccines11040829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/30/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
We are developing cytotoxic immunoconjugates (CICs) targeting the envelope protein (Env) of the Human Immunodeficiency Virus, type 1 (HIV) to purge the persistent reservoirs of viral infection. We have previously studied the ability of multiple monoclonal antibodies (mAbs) to deliver CICs to an HIV-infected cell. We have found that CICs targeted to the membrane-spanning gp41 domain of Env are most efficacious, in part because their killing is enhanced in the presence of soluble CD4. The ability of a mAb to deliver a CIC does not correlate with its ability to neutralize nor mediate Ab-dependent cellular cytotoxicity. In the current study, we seek to define the most effective anti-gp41 mAbs for delivering CICs to HIV-infected cells. To do this, we have evaluated a panel of human anti-gp41 mAbs for their ability to bind and kill two different Env-expressing cell lines: persistently infected H9/NL4-3 and constitutively transfected HEK293/92UG. We measured the binding and cytotoxicity of each mAb in the presence and absence of soluble CD4. We found that mAbs to the immunodominant helix-loop-helix region (ID-loop) of gp41 are most effective, whereas neutralizing mAbs to the fusion peptide, gp120/gp41 interface, and the membrane proximal external region (MPER) are relatively ineffective at delivering CICs. There was only a weak correlation between antigen exposure and killing activity. The results show that the ability to deliver an effective IC and neutralization are distinct functions of mAbs.
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Affiliation(s)
- Grant Klug
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Frances M Cole
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Mark D Hicar
- Department of Pediatrics, Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, Buffalo, NY 14203, USA
| | - Connie Watt
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Tami Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Seth H Pincus
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
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5
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Nguyen HT, Wang Q, Anang S, Sodroski JG. Characterization of the Human Immunodeficiency Virus (HIV-1) Envelope Glycoprotein Conformational States on Infectious Virus Particles. J Virol 2023; 97:e0185722. [PMID: 36815832 PMCID: PMC10062176 DOI: 10.1128/jvi.01857-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
Human immunodeficiency virus (HIV-1) entry into cells involves triggering of the viral envelope glycoprotein (Env) trimer ([gp120/gp41]3) by the primary receptor, CD4, and coreceptors, CCR5 or CXCR4. The pretriggered (State-1) conformation of the mature (cleaved) Env is targeted by broadly neutralizing antibodies (bNAbs), which are inefficiently elicited compared with poorly neutralizing antibodies (pNAbs). Here, we characterize variants of the moderately triggerable HIV-1AD8 Env on virions produced by an infectious molecular proviral clone; such virions contain more cleaved Env than pseudotyped viruses. We identified three types of cleaved wild-type AD8 Env trimers on virions: (i) State-1-like trimers preferentially recognized by bNAbs and exhibiting strong subunit association; (ii) trimers recognized by pNAbs directed against the gp120 coreceptor-binding region and exhibiting weak, detergent-sensitive subunit association; and (iii) a minor gp41-only population. The first Env population was enriched and the other Env populations reduced by introducing State-1-stabilizing changes in the AD8 Env or by treatment of the virions with crosslinker or the State-1-preferring entry inhibitor, BMS-806. These stabilized AD8 Envs were also more resistant to gp120 shedding induced by a CD4-mimetic compound or by incubation on ice. Conversely, a State-1-destabilized, CD4-independent AD8 Env variant exhibited weaker bNAb recognition and stronger pNAb recognition. Similar relationships between Env triggerability and antigenicity/shedding propensity on virions were observed for other HIV-1 strains. State-1 Envs on virions can be significantly enriched by minimizing the adventitious incorporation of uncleaved Env; stabilizing the pretriggered conformation by Env modification, crosslinking or BMS-806 treatment; strengthening Env subunit interactions; and using CD4-negative producer cells. IMPORTANCE Efforts to develop an effective HIV-1 vaccine have been frustrated by the inability to elicit broad neutralizing antibodies that recognize multiple virus strains. Such antibodies can bind a particular shape of the HIV-1 envelope glycoprotein trimer, as it exists on a viral membrane but before engaging receptors on the host cell. Here, we establish simple yet powerful assays to characterize the envelope glycoproteins in a natural context on virus particles. We find that, depending on the HIV-1 strain, some envelope glycoproteins change shape and fall apart, creating decoys that can potentially divert the host immune response. We identify requirements to keep the relevant envelope glycoprotein target for broad neutralizing antibodies intact on virus-like particles. These studies suggest strategies that should facilitate efforts to produce and use virus-like particles as vaccine immunogens.
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Affiliation(s)
- Hanh T. Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Qian Wang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Saumya Anang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Joseph G. Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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6
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Laumaea A, Marchitto L, Ding S, Beaudoin-Bussières G, Prévost J, Gasser R, Chatterjee D, Gendron-Lepage G, Medjahed H, Chen HC, Smith AB, Ding H, Kappes JC, Hahn BH, Kirchhoff F, Richard J, Duerr R, Finzi A. Small CD4 mimetics sensitize HIV-1-infected macrophages to antibody-dependent cellular cytotoxicity. Cell Rep 2023; 42:111983. [PMID: 36640355 PMCID: PMC9941794 DOI: 10.1016/j.celrep.2022.111983] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 10/25/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
HIV-1 envelope (Env) conformation determines the susceptibility of infected CD4+ T cells to antibody-dependent cellular cytotoxicity (ADCC). Upon interaction with CD4, Env adopts more "open" conformations, exposing ADCC epitopes. HIV-1 limits Env-CD4 interaction and protects infected cells against ADCC by downregulating CD4 via Nef, Vpu, and Env. Limited data exist, however, of the role of these proteins in downmodulating CD4 on infected macrophages and how this impacts Env conformation. While Nef, Vpu, and Env are all required to efficiently downregulate CD4 on infected CD4+ T cells, we show here that any one of these proteins is sufficient to downmodulate most CD4 from the surface of infected macrophages. Consistent with this finding, Nef and Vpu have a lesser impact on Env conformation and ADCC sensitivity in infected macrophages compared with CD4+ T cells. However, treatment of infected macrophages with small CD4 mimetics exposes vulnerable CD4-induced Env epitopes and sensitizes them to ADCC.
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Affiliation(s)
- Annemarie Laumaea
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada.
| | - Lorie Marchitto
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Shilei Ding
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada
| | - Guillaume Beaudoin-Bussières
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Romain Gasser
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | | | | | | | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL 35233, USA
| | - Beatrice H Hahn
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Ralf Duerr
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada.
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7
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Prévost J, Anand SP, Rajashekar JK, Zhu L, Richard J, Goyette G, Medjahed H, Gendron-Lepage G, Chen HC, Chen Y, Horwitz JA, Grunst MW, Zolla-Pazner S, Haynes BF, Burton DR, Flavell RA, Kirchhoff F, Hahn BH, Smith AB, Pazgier M, Nussenzweig MC, Kumar P, Finzi A. HIV-1 Vpu restricts Fc-mediated effector functions in vivo. Cell Rep 2022; 41:111624. [PMID: 36351384 PMCID: PMC9703018 DOI: 10.1016/j.celrep.2022.111624] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 09/02/2022] [Accepted: 10/17/2022] [Indexed: 11/09/2022] Open
Abstract
Non-neutralizing antibodies (nnAbs) can eliminate HIV-1-infected cells via antibody-dependent cellular cytotoxicity (ADCC) and were identified as a correlate of protection in the RV144 vaccine trial. Fc-mediated effector functions of nnAbs were recently shown to alter the course of HIV-1 infection in vivo using a vpu-defective virus. Since Vpu is known to downregulate cell-surface CD4, which triggers conformational changes in the viral envelope glycoprotein (Env), we ask whether the lack of Vpu expression was linked to the observed nnAbs activity. We find that restoring Vpu expression greatly reduces nnAb recognition of infected cells, rendering them resistant to ADCC. Moreover, administration of nnAbs in humanized mice reduces viral loads only in animals infected with a vpu-defective but not with a wild-type virus. CD4-mimetics administration, known to "open" Env and expose nnAb epitopes, renders wild-type viruses sensitive to nnAbs Fc-effector functions. This work highlights the importance of Vpu-mediated evasion of humoral responses.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada.
| | - Sai Priya Anand
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Jyothi Krishnaswamy Rajashekar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Li Zhu
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | | | | | | | - Hung-Ching Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Yaozong Chen
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4712, USA
| | - Joshua A Horwitz
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Michael W Grunst
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Susan Zolla-Pazner
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Departments of Medicine and Immunology, Duke University School of Medicine, Durham, NC 27710, USA; Consortium for HIV/AIDS Vaccine Development (CHAVD), Duke University, Durham, NC 27710, USA
| | - Dennis R Burton
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Consortium for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, Harvard University, Cambridge, MA 02139, USA
| | - Richard A Flavell
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Beatrice H Hahn
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Amos B Smith
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Marzena Pazgier
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4712, USA
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Priti Kumar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada.
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8
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Cook JD, Khondker A, Lee JE. Conformational plasticity of the HIV-1 gp41 immunodominant region is recognized by multiple non-neutralizing antibodies. Commun Biol 2022; 5:291. [PMID: 35361878 PMCID: PMC8971491 DOI: 10.1038/s42003-022-03235-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 03/08/2022] [Indexed: 12/17/2022] Open
Abstract
The early humoral immune response to acute HIV-1 infection is largely non-neutralizing. The principal target of these antibodies is the primary immunodominant region (PID) on the gp41 fusion protein. The PID is a highly conserved 15-residue region displayed on the surface of HIV-1 virions. In this study, we analyzed the humoral determinants of HIV-1 gp41 PID binding using biophysical, structural, and computational methods. In complex with a patient-derived near-germline antibody fragment, the PID motif adopts an elongated random coil, whereas the PID bound to affinity-matured Fab adopts a strand-turn-helix conformation. Molecular dynamics simulations showed that the PID is structurally plastic suggesting that the PID can form an ensemble of structural states recognized by various non-neutralizing antibodies, facilitating HIV-1 immunodominance observed in acute and chronic HIV-1 infections. An improved understanding of how the HIV-1 gp41 PID misdirects the early humoral response should guide the development of an effective HIV-1 vaccine. The 15-amino-acid primary immunodominant (PID) region on HIV-1 gp41 adopts an ensemble of conformational states. This conformational plasticity is suggested to misdirect the early humoral immune response.
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Affiliation(s)
- Jonathan D Cook
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Department of Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Adree Khondker
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Jeffrey E Lee
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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9
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Functional and Highly Cross-Linkable HIV-1 Envelope Glycoproteins Enriched in a Pretriggered Conformation. J Virol 2022; 96:e0166821. [PMID: 35343783 DOI: 10.1128/jvi.01668-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Binding to the receptor, CD4, drives the pretriggered, "closed" (state-1) conformation of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer into more "open" conformations (states 2 and 3). Broadly neutralizing antibodies, which are elicited inefficiently, mostly recognize the state-1 Env conformation, whereas the more commonly elicited poorly neutralizing antibodies recognize states 2/3. HIV-1 Env metastability has created challenges for defining the state-1 structure and developing immunogens mimicking this labile conformation. The availability of functional state-1 Envs that can be efficiently cross-linked at lysine and/or acidic amino acid residues might assist these endeavors. To that end, we modified HIV-1AD8 Env, which exhibits an intermediate level of triggerability by CD4. We introduced lysine/acidic residues at positions that exhibit such polymorphisms in natural HIV-1 strains. Env changes that were tolerated with respect to gp120-gp41 processing, subunit association, and virus entry were further combined. Two common polymorphisms, Q114E and Q567K, as well as a known variant, A582T, additively rendered pseudoviruses resistant to cold, soluble CD4, and a CD4-mimetic compound, phenotypes indicative of stabilization of the pretriggered state-1 Env conformation. Combining these changes resulted in two lysine-rich HIV-1AD8 Env variants (E.2 and AE.2) with neutralization- and cold-resistant phenotypes comparable to those of natural, less triggerable tier 2/3 HIV-1 isolates. Compared with these and the parental Envs, the E.2 and AE.2 Envs were cleaved more efficiently and exhibited stronger gp120-trimer association in detergent lysates. These highly cross-linkable Envs enriched in a pretriggered conformation should assist characterization of the structure and immunogenicity of this labile state. IMPORTANCE The development of an efficient vaccine is critical for combating HIV-1 infection worldwide. However, the instability of the pretriggered shape (state 1) of the viral envelope glycoprotein (Env) makes it difficult to raise neutralizing antibodies against HIV-1. Here, by introducing multiple changes in Env, we derived two HIV-1 Env variants that are enriched in state 1 and can be efficiently cross-linked to maintain this shape. These Env complexes are more stable in detergent, assisting their purification. Thus, our study provides a path to a better characterization of the native pretriggered Env, which should assist vaccine development.
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10
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Ardizzone CM, Albritton HL, Lillis RA, Bagnetto CEL, Shen L, Cavacini LA, Kozlowski PA, Quayle AJ. Human genital antibody-mediated inhibition of Chlamydia trachomatis infection and evidence for ompA genotype-specific neutralization. PLoS One 2021; 16:e0258759. [PMID: 34662351 PMCID: PMC8523062 DOI: 10.1371/journal.pone.0258759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 10/04/2021] [Indexed: 11/19/2022] Open
Abstract
The endocervix, the primary site of Chlamydia trachomatis (Ct) infection in women, has a unique repertoire of locally synthesized IgG and secretory IgA (SIgA) with contributions from serum IgG. Here, we assessed the ability of genital and serum-derived IgG and IgA from women with a recent positive Ct test to neutralize Ct elementary bodies (EBs) and inhibit inclusion formation in vitro in human endocervical epithelial cells. We also determined if neutralization was influenced by the major outer membrane protein (MOMP) of the infecting strain, as indicated by ompA gene sequencing and genotyping. At equivalent low concentrations of Ct EB (D/UW-3/Cx + E/UW-5/Cx)-specific antibody, genital-derived IgG and IgA and serum IgA, but not serum IgG, significantly inhibited inclusion formation, with genital IgA being most effective, followed by genital IgG, then serum IgA. The well-characterized Ct genotype D strain, D/UW-3/Cx, was neutralized by serum-derived IgG from patients infected with genotype D strains, genital IgG from patients infected with genotype D or E strains, and by genital IgA from patients infected with genotype D, E, or F strains. Additionally, inhibition of D/UW-3/Cx infection by whole serum, rather than purified immunoglobulin, was associated with levels of serum EB-specific IgG rather than the genotype of infecting strain. In contrast, a Ct genotype Ia clinical isolate, Ia/LSU-56/Cx, was neutralized by whole serum in a genotype and genogroup-specific manner, and inhibition also correlated with EB-specific IgG concentrations in serum. Taken together, these data suggest that (i) genital IgA most effectively inhibits Ct infection in vitro, (ii) human antibody-mediated inhibition of Ct infection is significantly influenced by the ompA genotype of the infecting strain, (iii) the genital antibody repertoire develops or matures differently compared to systemic antibody, and (iv) ompA genotype-specificity of inhibition of infection by whole serum can be overcome by high concentrations of Ct-specific IgG.
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Affiliation(s)
- Caleb M. Ardizzone
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Hannah L. Albritton
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Rebecca A. Lillis
- Division of Infectious Diseases, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Caitlyn E. L. Bagnetto
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Li Shen
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Lisa A. Cavacini
- MassBiologics, University of Massachusetts Medical School, Boston, Massachusetts, United States of America
| | - Pamela A. Kozlowski
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Alison J. Quayle
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
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11
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Gonelli CA, King HAD, Mackenzie C, Sonza S, Center RJ, Purcell DFJ. Immunogenicity of HIV-1-Based Virus-Like Particles with Increased Incorporation and Stability of Membrane-Bound Env. Vaccines (Basel) 2021; 9:239. [PMID: 33801906 PMCID: PMC8002006 DOI: 10.3390/vaccines9030239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 01/04/2023] Open
Abstract
An optimal prophylactic vaccine to prevent human immunodeficiency virus (HIV-1) transmission should elicit protective antibody responses against the HIV-1 envelope glycoprotein (Env). Replication-incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present virion-associated Env with a native-like structure during vaccination that closely resembles that encountered on infectious virus. Here, we optimized the incorporation of Env into previously designed mature-form VLPs (mVLPs) and assessed their immunogenicity in mice. The incorporation of Env into mVLPs was increased by replacing the Env transmembrane and cytoplasmic tail domains with those of influenza haemagglutinin (HA-TMCT). Furthermore, Env was stabilized on the VLP surface by introducing an interchain disulfide and proline substitution (SOSIP) mutations typically employed to stabilize soluble Env trimers. The resulting mVLPs efficiently presented neutralizing antibody epitopes while minimizing exposure of non-neutralizing antibody sites. Vaccination of mice with mVLPs elicited a broader range of Env-specific antibody isotypes than Env presented on immature VLPs or extracellular vesicles. The mVLPs bearing HA-TMCT-modified Env consistently induced anti-Env antibody responses that mediated modest neutralization activity. These mVLPs are potentially useful immunogens for eliciting neutralizing antibody responses that target native Env epitopes on infectious HIV-1 virions.
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Affiliation(s)
- Christopher A. Gonelli
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; (C.A.G.); (H.A.D.K.); (C.M.); (S.S.); (R.J.C.)
| | - Hannah A. D. King
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; (C.A.G.); (H.A.D.K.); (C.M.); (S.S.); (R.J.C.)
- Viral Entry and Vaccines Laboratory, Disease Elimination, Burnet Institute, Melbourne, VIC 3004, Australia
| | - Charlene Mackenzie
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; (C.A.G.); (H.A.D.K.); (C.M.); (S.S.); (R.J.C.)
| | - Secondo Sonza
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; (C.A.G.); (H.A.D.K.); (C.M.); (S.S.); (R.J.C.)
| | - Rob J. Center
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; (C.A.G.); (H.A.D.K.); (C.M.); (S.S.); (R.J.C.)
- Viral Entry and Vaccines Laboratory, Disease Elimination, Burnet Institute, Melbourne, VIC 3004, Australia
| | - Damian F. J. Purcell
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia; (C.A.G.); (H.A.D.K.); (C.M.); (S.S.); (R.J.C.)
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12
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Hoffmann R, Ruegamer T, Schaubächer J, Rohrhofer A, Kirmeß P, Fiebig KM, Schmidt B, Eichler J. Exploring Viral Interference Using Peptides: Molecular Determinants of HIV-1 Inhibition by a Peptide Derived from Human Pegivirus-1 Envelope Protein E2. ChemMedChem 2021; 16:1290-1296. [PMID: 33378104 PMCID: PMC8248410 DOI: 10.1002/cmdc.202000892] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/29/2020] [Indexed: 01/13/2023]
Abstract
Co-infection with the human pegivirus 1 (HPgV-1) often has a beneficial effect on disease progression in HIV-1-infected individuals. Several HPgV-1 proteins and peptides, including a 20-mer peptide (P6-2) derived from the N-terminal region of the HPgV-1 surface protein E2, have been associated with this phenomenon, which is referred to as viral interference. We identified the cysteine residues, the hydrophobic core tetrapeptide, as well as the C-terminal negative charge as key factors for the HIV-1 inhibitory activity of P6-2. Analysis of mutations in P6-2-resistant HIV-1 indicated a binding site for the peptide in the HIV-1 envelope glycoprotein gp120. In fact, P6-2 was shown to bind to soluble gp120, as well as to a peptide presenting the gp120 V3 loop. Furthermore, the HIV-1 inhibitory activity of P6-2 could be revoked by the V3 loop peptide, thus indicating a molecular mechanism that involves interaction of P6-2 with the gp120 V3 loop.
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Affiliation(s)
- Rebecca Hoffmann
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058, Erlangen, Germany
| | - Tamara Ruegamer
- Institute of Clinical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Johanna Schaubächer
- Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Anette Rohrhofer
- Institute of Clinical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Peter Kirmeß
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058, Erlangen, Germany
| | - Karen M Fiebig
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058, Erlangen, Germany
| | - Barbara Schmidt
- Institute of Clinical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany.,Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Jutta Eichler
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058, Erlangen, Germany
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13
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Phage-DMS: A Comprehensive Method for Fine Mapping of Antibody Epitopes. iScience 2020; 23:101622. [PMID: 33089110 PMCID: PMC7566095 DOI: 10.1016/j.isci.2020.101622] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/08/2020] [Accepted: 09/24/2020] [Indexed: 12/31/2022] Open
Abstract
Understanding the antibody response is critical to developing vaccine and antibody-based therapies and has inspired the recent development of new methods to isolate antibodies. Methods to define the antibody-antigen interactions that determine specificity or allow escape have not kept pace. We developed Phage-DMS, a method that combines two powerful approaches-immunoprecipitation of phage peptide libraries and deep mutational scanning (DMS)-to enable high-throughput fine mapping of antibody epitopes. As an example, we designed sequences encoding all possible amino acid variants of HIV Envelope to create phage libraries. Using Phage-DMS, we identified sites of escape predicted using other approaches for four well-characterized HIV monoclonal antibodies with known linear epitopes. In some cases, the results of Phage-DMS refined the epitope beyond what was determined in previous studies. This method has the potential to rapidly and comprehensively screen many antibodies in a single experiment to define sites essential for binding interactions.
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14
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Enhancing natural killer cell function with gp41-targeting bispecific antibodies to combat HIV infection. AIDS 2020; 34:1313-1323. [PMID: 32287071 DOI: 10.1097/qad.0000000000002543] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE(S) The aim of this study was to develop and evaluate the activity of bispecific antibodies (bsAbs) to enhance natural killer (NK) cell antibody-dependent cellular cytotoxicity (ADCC) against HIV-infected cells. DESIGN These bsAbs are based on patient-derived antibodies targeting the conserved gp41 stump of HIV Env, and also incorporate a high-affinity single chain variable fragment (scFv) targeting the activating receptor CD16 on NK cells. Overall, we expect the bsAbs to provide increased affinity and avidity over their corresponding mAbs, allowing for improved ADCC activity against Env-expressing target cells. METHODS bsAbs and their corresponding mAbs were expressed in 293T cells and purified. The binding of bsAbs and mAbs to their intended targets was determined using Bio-Layer Interferometry, as well as flow cytometry based binding assays on in-vitro infected cells. The ability of these bsAbs to improve NK cell activity against HIV-infected cells was tested using in-vitro co-culture assays, using flow cytometry and calcein release to analyse NK cell degranulation and target cell killing, respectively. RESULTS The bsAbs-bound gp41 with similar affinity to their corresponding mAbs had increased affinity for CD16. The bsAbs also bound to primary CD4 T cells infected in vitro with two different strains of HIV. In addition, the bsAbs induce increased NK cell degranulation and killing of autologous HIV-infected CD4 T cells. CONCLUSION On the basis of their in-vitro killing efficacy, bsAbs may provide a promising strategy to improve NK-mediated immune targeting of infected cells during HIV infection.
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15
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Joshi VR, Newman RM, Pack ML, Power KA, Munro JB, Okawa K, Madani N, Sodroski JG, Schmidt AG, Allen TM. Gp41-targeted antibodies restore infectivity of a fusion-deficient HIV-1 envelope glycoprotein. PLoS Pathog 2020; 16:e1008577. [PMID: 32392227 PMCID: PMC7241850 DOI: 10.1371/journal.ppat.1008577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/21/2020] [Accepted: 04/24/2020] [Indexed: 02/07/2023] Open
Abstract
The HIV-1 envelope glycoprotein (Env) mediates viral entry via conformational changes associated with binding the cell surface receptor (CD4) and coreceptor (CCR5/CXCR4), resulting in subsequent fusion of the viral and cellular membranes. While the gp120 Env surface subunit has been extensively studied for its role in viral entry and evasion of the host immune response, the gp41 transmembrane glycoprotein and its role in natural infection are less well characterized. Here, we identified a primary HIV-1 Env variant that consistently supports >300% increased viral infectivity in the presence of autologous or heterologous HIV-positive plasma. However, in the absence of HIV-positive plasma, viruses with this Env exhibited reduced infectivity that was not due to decreased CD4 binding. Using Env chimeras and sequence analysis, we mapped this phenotype to a change Q563R, in the gp41 heptad repeat 1 (HR1) region. We demonstrate that Q563R reduces viral infection by disrupting formation of the gp41 six-helix bundle required for virus-cell membrane fusion. Intriguingly, antibodies that bind cluster I epitopes on gp41 overcome this inhibitory effect, restoring infectivity to wild-type levels. We further demonstrate that the Q563R change increases HIV-1 sensitivity to broadly neutralizing antibodies (bNAbs) targeting the gp41 membrane-proximal external region (MPER). In summary, we identify an HIV-1 Env variant with impaired infectivity whose Env functionality is restored through the binding of host antibodies. These data contribute to our understanding of gp41 residues involved in membrane fusion and identify a mechanism by which host factors can alleviate a viral defect.
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Affiliation(s)
- Vinita R. Joshi
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Virology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ruchi M. Newman
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Melissa L. Pack
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Karen A. Power
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - James B. Munro
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Ken Okawa
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Navid Madani
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Joseph G. Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Aaron G. Schmidt
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Todd M. Allen
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
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16
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Monoclonal Antibody 2C6 Targets a Cross-Clade Conformational Epitope in gp41 with Highly Active Antibody-Dependent Cell Cytotoxicity. J Virol 2019; 93:JVI.00772-19. [PMID: 31217246 DOI: 10.1128/jvi.00772-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/13/2019] [Indexed: 12/11/2022] Open
Abstract
Previous studies in our laboratory characterized a panel of highly mutated HIV-specific conformational epitope-targeting antibodies (Abs) from a panel of HIV-infected long-term nonprogressors (LTNPs). Despite binding HIV envelope protein and having a high number of somatic amino acid mutations, these Abs had poor neutralizing activity. Because of the evidence of antigen-driven selection and the long CDR3 region (21 amino acids [aa]), we further characterized the epitope targeting of monoclonal Ab (MAb) 76-Q3-2C6 (2C6). We confirmed that 2C6 binds preferentially to trimeric envelope and recognizes the clades A, B, and C SOSIP trimers. 2C6 binds gp140 constructs of clades A, B, C, and D, suggesting a conserved binding site that we localized to the ectodomain of gp41. Ab competition with MAb 50-69 suggested this epitope localizes near aa 579 to 613 (referenced to HXB2 gp160). Peptide library scanning showed consistent binding in this region but to only a single peptide. Lack of overlapping peptide binding supported a nonlinear epitope structure. The significance of this site is supported by 2C6 having Ab-dependent cell cytotoxicity (ADCC) against envelope proteins from two clades. Using 2C6 and variants, alanine scanning mutagenesis identified three amino acids (aa 592, 595, and 596) in the overlapping region of the previously identified peptide. Additional amino acids at sites 524 and 579 were also identified, helping explain its conformational requirement. The fact that different amino acids were included in the epitope depending on the targeted protein supports the conclusion that 2C6 targets a native conformational epitope. When we mapped these amino acids on the trimerized structure, they spanned across oligomers, supporting the notion that the epitope targeted by 2C6 lies in a recessed pocket between two gp41 oligomers. A complete understanding of the epitope specificity of ADCC-mediating Abs is essential for developing effective immunization strategies that optimize protection by these Abs.IMPORTANCE This paper further defines the function and area of the HIV trimeric envelope protein targeted by the monoclonal antibody 2C6. 2C6 binding is influenced by amino acid mutations across two separate gp41 sections of the envelope trimer. This epitope is recognized on multiple clades (variant groups of circulating viruses) of gp41, gp140 trimers, and SOSIP trimers. For the clades tested, 2C6 has robust ADCC. As the target of 2C6 is available in the major clades of HIV and has robust ADCC activity, further definition and appreciation of targeting of antibodies similar to 2C6 during vaccine development should be considered.
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17
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Ray K, Mengistu M, Orlandi C, Pazgier M, Lewis GK, DeVico AL. Concurrent Exposure of Neutralizing and Non-neutralizing Epitopes on a Single HIV-1 Envelope Structure. Front Immunol 2019; 10:1512. [PMID: 31338095 PMCID: PMC6628914 DOI: 10.3389/fimmu.2019.01512] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 06/17/2019] [Indexed: 01/14/2023] Open
Abstract
The trimeric envelope spikes on the HIV-1 virus surface initiate infection and comprise key targets for antiviral humoral responses. Circulating virions variably present intact envelope spikes, which react with neutralizing antibodies; and altered envelope structures, which bind non-neutralizing antibodies. Once bound, either type of antibody can enable humoral effector mechanisms with the potential to control HIV-1 infection in vivo. However, it is not clear how the presentation of neutralizing vs. non-neutralizing epitopes defines distinct virus populations and/or envelope structures on single particles. Here we used single-virion fluorescence correlation spectroscopy (FCS), fluorescence resonance energy transfer (FRET), and two-color coincidence FCS approaches to examine whether neutralizing and non-neutralizing antibodies are presented by the same envelope structure. Given the spatial requirements for donor-acceptor energy transfer (≤10 nm), FRET signals generated by paired neutralizing and non-neutralizing fluorescent Fabs should occur via proximal binding to the same target antigen. Fluorescent-labeled Fabs of the neutralizing anti-gp120 antibodies 2G12 and b12 were combined with Fabs of the non-neutralizing anti-gp41 antibody F240, previously thought to mainly bind gp41 "stumps." We find that both 2G12-F240 and/or b12-F240 Fab combinations generate FRET signals on multiple types of virions in solution. FRET efficiencies position the neutralizing and non-neutralizing epitopes between 7.1 and 7.8 nm apart; potentially fitting within the spatial dimensions of a single trimer-derived structure. Further, the frequency of FRET detection suggests that at least one of such structures occurs on the majority of particles in a virus population. Thus, there is frequent, overlapping presentation of non-neutralizing and neutralizing epitope on freely circulating HIV-1 surfaces. Such information provides a broader perspective of how anti-HIV humoral immunity interfaces with circulating virions.
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Affiliation(s)
- Krishanu Ray
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States,*Correspondence: Krishanu Ray
| | - Meron Mengistu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Chiara Orlandi
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marzena Pazgier
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - George K. Lewis
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anthony L. DeVico
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
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18
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Gonelli CA, Khoury G, Center RJ, Purcell DFJ. HIV-1-based Virus-like Particles that Morphologically Resemble Mature, Infectious HIV-1 Virions. Viruses 2019; 11:v11060507. [PMID: 31159488 PMCID: PMC6630479 DOI: 10.3390/v11060507] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/23/2019] [Accepted: 05/29/2019] [Indexed: 01/04/2023] Open
Abstract
A prophylactic vaccine eliciting both broad neutralizing antibodies (bNAbs) to the HIV-1 envelope glycoprotein (Env) and strong T cell responses would be optimal for preventing HIV-1 transmissions. Replication incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present authentic-structured, virion-associated Env to elicit bNAbs, and also stimulate T cell responses. Here, we optimize our DNA vaccine plasmids as VLP expression vectors for efficient Env incorporation and budding. The original vector that was used in human trials inefficiently produced VLPs, but maximized safety by inactivating RNA genome packaging, enzyme functions that are required for integration into the host genome, and deleting accessory proteins Vif, Vpr, and Nef. These original DNA vaccine vectors generated VLPs with incomplete protease-mediated cleavage of Gag and were irregularly sized. Mutations to restore function within the defective genes revealed that several of the reverse transcriptase (RT) deletions mediated this immature phenotype. Here, we made efficient budding, protease-processed, and mature-form VLPs that resembled infectious virions by introducing alternative mutations that completely removed the RT domain, but preserved most other safety mutations. These VLPs, either expressed from DNA vectors in vivo or purified after expression in vitro, are potentially useful immunogens that can be used to elicit antibody responses that target Env on fully infectious HIV-1 virions.
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Affiliation(s)
- Christopher A Gonelli
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
| | - Georges Khoury
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
| | - Rob J Center
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
- Viral Entry and Vaccines Laboratory, Disease Elimination, Burnet Institute, Melbourne, Victoria 3004, Australia.
| | - Damian F J Purcell
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
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19
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Gawron MA, Duval M, Carbone C, Jaiswal S, Wallace A, Martin JC, Dauphin A, Brehm MA, Greiner DL, Shultz LD, Luban J, Cavacini LA. Human Anti-HIV-1 gp120 Monoclonal Antibodies with Neutralizing Activity Cloned from Humanized Mice Infected with HIV-1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2019; 202:799-804. [PMID: 30593536 PMCID: PMC6344273 DOI: 10.4049/jimmunol.1801085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/16/2018] [Indexed: 12/14/2022]
Abstract
Broadly neutralizing, anti-HIV-1 gp120 mAbs have been isolated from infected individuals, and there is considerable interest in developing these reagents for Ab-based immunoprophylaxis and treatment. As a means to identify potentially new anti-HIV Abs, we exploited humanized NOD-scid IL2rγnull mice systemically infected with HIV-1 to generate a wide variety of Ag-specific human mAbs. The Abs were encoded by a diverse range of variable gene families and Ig classes, including IgA, and several showed significant levels of somatic mutation. Moreover, the isolated Abs not only bound target Ags with similar affinity as broadly neutralizing Abs, they also demonstrated neutralizing ability against multiple HIV-1 clades. The use of humanized mice will allow us to use our knowledge of HIV-1 gp120 structure and function, and the immune response targeting this protein, to generate native human prophylactic Abs to reduce the infection and spread of HIV-1.
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Affiliation(s)
- Melissa A Gawron
- MassBiologics of the University of Massachusetts Medical School, Boston, MA 02126
| | - Mark Duval
- MassBiologics of the University of Massachusetts Medical School, Boston, MA 02126
| | - Claudia Carbone
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Smita Jaiswal
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Aaron Wallace
- MassBiologics of the University of Massachusetts Medical School, Boston, MA 02126
| | - Joseph C Martin
- MassBiologics of the University of Massachusetts Medical School, Boston, MA 02126
| | - Ann Dauphin
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Michael A Brehm
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Dale L Greiner
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655; and
| | | | - Jeremy Luban
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655; and
| | - Lisa A Cavacini
- MassBiologics of the University of Massachusetts Medical School, Boston, MA 02126;
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20
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Williams KL, Stumpf M, Naiman NE, Ding S, Garrett M, Gobillot T, Vézina D, Dusenbury K, Ramadoss NS, Basom R, Kim PS, Finzi A, Overbaugh J. Identification of HIV gp41-specific antibodies that mediate killing of infected cells. PLoS Pathog 2019; 15:e1007572. [PMID: 30779811 PMCID: PMC6396944 DOI: 10.1371/journal.ppat.1007572] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 03/01/2019] [Accepted: 01/08/2019] [Indexed: 11/19/2022] Open
Abstract
Antibodies that mediate killing of HIV-infected cells through antibody-dependent cellular cytotoxicity (ADCC) have been implicated in protection from HIV infection and disease progression. Despite these observations, these types of HIV antibodies are understudied compared to neutralizing antibodies. Here we describe four monoclonal antibodies (mAbs) obtained from one individual that target the HIV transmembrane protein, gp41, and mediate ADCC activity. These four mAbs arose from independent B cell lineages suggesting that in this individual, multiple B cell responses were induced by the gp41 antigen. Competition and phage peptide display mapping experiments suggested that two of the mAbs target epitopes in the cysteine loop that are highly conserved and a common target of HIV gp41-specific antibodies. The amino acid sequences that bind these mAbs are overlapping but distinct. The two other mAbs were competed by mAbs that target the C-terminal heptad repeat (CHR) and the fusion peptide proximal region (FPPR) and appear to both target a similar unique conformational epitope. These gp41-specific mAbs mediated killing of infected cells that express high levels of Env due to either pre-treatment with interferon or deletion of vpu to increase levels of BST-2/Tetherin. They also mediate killing of target cells coated with various forms of the gp41 protein, including full-length gp41, gp41 ectodomain or a mimetic of the gp41 stump. Unlike many ADCC mAbs that target HIV gp120, these gp41-mAbs are not dependent on Env structural changes associated with membrane-bound CD4 interaction. Overall, the characterization of these four new mAbs that target gp41 and mediate ADCC provides evidence for diverse gp41 B cell lineages with overlapping but distinct epitopes within an individual. Such antibodies that can target various forms of envelope protein could represent a common response to a relatively conserved HIV epitope for a vaccine.
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Affiliation(s)
- Katherine L. Williams
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
| | - Megan Stumpf
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
| | - Nicole Elise Naiman
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA United States of America
- Medical Scientist Training Program, University of Washington, Seattle WA, United States of America
| | - Shilei Ding
- Department of Microbiology, Infectious Diseases and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Meghan Garrett
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA United States of America
| | - Theodore Gobillot
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA United States of America
- Medical Scientist Training Program, University of Washington, Seattle WA, United States of America
| | - Dani Vézina
- Department of Microbiology, Infectious Diseases and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Katharine Dusenbury
- Medical Scientist Training Program, University of Washington, Seattle WA, United States of America
- Divisions of Basic Sciences and Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Nitya S. Ramadoss
- Stanford ChEM-H and Department of Biochemistry, Stanford University, Stanford, CA, United States of America
| | - Ryan Basom
- Genomics and Bioinformatics Shared Resource, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Peter S. Kim
- Stanford ChEM-H and Department of Biochemistry, Stanford University, Stanford, CA, United States of America
- Chan Zuckerberg Biohub, San Francisco, CA, United States of America
| | - Andrés Finzi
- Department of Microbiology, Infectious Diseases and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
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21
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Induction of a Tier-1-Like Phenotype in Diverse Tier-2 Isolates by Agents That Guide HIV-1 Env to Perturbation-Sensitive, Nonnative States. J Virol 2017; 91:JVI.00174-17. [PMID: 28490588 DOI: 10.1128/jvi.00174-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/24/2017] [Indexed: 01/05/2023] Open
Abstract
The envelope glycoproteins (Envs) on the surfaces of HIV-1 particles are targeted by host antibodies. Primary HIV-1 isolates demonstrate different global sensitivities to antibody neutralization; tier-1 isolates are sensitive, whereas tier-2 isolates are more resistant. Single-site mutations in Env can convert tier-2 into tier-1-like viruses. We hypothesized that such global change in neutralization sensitivity results from weakening of intramolecular interactions that maintain Env integrity. Three strategies commonly applied to perturb protein structure were tested for their effects on global neutralization sensitivity: exposure to low temperature, Env-activating ligands, and a chaotropic agent. A large panel of diverse tier-2 isolates from clades B and C was analyzed. Incubation at 0°C, which globally weakens hydrophobic interactions, causes gradual and reversible exposure of the coreceptor-binding site. In the cold-induced state, Envs progress at isolate-specific rates to unstable forms that are sensitive to antibody neutralization and then gradually lose function. Agents that mimic the effects of CD4 (CD4Ms) also induce reversible structural changes to states that exhibit isolate-specific stabilities. The chaotropic agent urea (at low concentrations) does not affect the structure or function of native Env. However, urea efficiently perturbs metastable states induced by cold and CD4Ms and increases their sensitivity to antibody neutralization and their inactivation rates Therefore, chemical and physical agents can guide Env from the stable native state to perturbation-sensitive forms and modulate their stability to bestow tier-1-like properties on primary tier-2 strains. These concepts can be applied to enhance the potency of vaccine-elicited antibodies and microbicides at mucosal sites of HIV-1 transmission.IMPORTANCE An effective vaccine to prevent transmission of HIV-1 is a primary goal of the scientific and health care communities. Vaccine-elicited antibodies target the viral envelope glycoproteins (Envs) and can potentially inhibit infection. However, the potency of such antibodies is generally low. Single-site mutations in Env can enhance the global sensitivity of HIV-1 to neutralization by antibodies. We found that such a hypersensitivity phenotype can also be induced by agents that destabilize protein structure. Exposure to 0°C or low concentrations of Env-activating ligands gradually guides Env to metastable forms that expose cryptic epitopes and that are highly sensitive to neutralization. Low concentrations of the chaotropic agent urea do not affect native Env but destabilize perturbed states induced by cold or CD4Ms and increase their neutralization. The concept of enhancing antibody sensitivity by chemical agents that affect the structural stability of proteins can be applied to increase the potency of topical microbicides and vaccine-elicited antibodies.
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Abstract
It is clear that antibodies can play a pivotal role in preventing the transmission of HIV-1 and large efforts to identify an effective antibody-based vaccine to quell the epidemic. Shortly after HIV-1 was discovered as the cause of AIDS, the search for epitopes recognized by neutralizing antibodies became the driving strategy for an antibody-based vaccine. Neutralization escape variants were discovered shortly thereafter, and, after almost three decades of investigation, it is now known that autologous neutralizing antibody responses and their selection of neutralization resistant HIV-1 variants can lead to broadly neutralizing antibodies in some infected individuals. This observation drives an intensive effort to identify a vaccine to elicit broadly neutralizing antibodies. In contrast, there has been less systematic study of antibody specificities that must rely mainly or exclusively on other protective mechanisms, although non-human primate (NHP) studies as well as the RV144 vaccine trial indicate that non-neutralizing antibodies can contribute to protection. Here we propose a novel strategy to identify new epitope targets recognized by these antibodies for which viral escape is unlikely or impossible.
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Affiliation(s)
- George K Lewis
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Marzena Pazgier
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Anthony L DeVico
- Division of Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
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23
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Gohain N, Tolbert WD, Orlandi C, Richard J, Ding S, Chen X, Bonsor DA, Sundberg EJ, Lu W, Ray K, Finzi A, Lewis GK, Pazgier M. Molecular basis for epitope recognition by non-neutralizing anti-gp41 antibody F240. Sci Rep 2016; 6:36685. [PMID: 27827447 PMCID: PMC5101508 DOI: 10.1038/srep36685] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 10/18/2016] [Indexed: 01/17/2023] Open
Abstract
Antibody-dependent cell-mediated cytotoxicity (ADCC) by non-neutralizing antibodies (nnAbs) specific to the HIV envelope (Env) glycoproteins present at the surface of virus sensitized or infected cells plays a role in the effective adaptive immune response to HIV. Here, we explore the molecular basis for the epitope at the disulfide loop region (DLR) of the principal immunodominant domain of gp41, recognized by the well-known nnAb F240. Our structural studies reveal details of the F240-gp41 interface and describe a structure of DLR that is distinct from known conformations of this region studied in the context of either CD4-unliganded Env trimer or the gp41 peptide in the unbound state. These data coupled with binding and functional analyses indicate that F240 recognizes non-trimeric Env forms which are significantly overexpressed on intact virions but poorly represented at surfaces of cells infected with infectious molecular clones and endogenously-infected CD4 T cells from HIV-1-infected individuals. Furthermore, although we detect ADCC activities of F240 against cells spinoculated with intact virions, our data suggest that these activities result from F240 recognition of gp41 stumps or misfolded Env variants present on virions rather than its ability to recognize functional gp41 transition structures emerging on trimeric Env post CD4 receptor engagement.
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Affiliation(s)
- Neelakshi Gohain
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Biochemistry and Molecular Biology, the University of Maryland School of Medicine, Baltimore, USA
| | - William D Tolbert
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Biochemistry and Molecular Biology, the University of Maryland School of Medicine, Baltimore, USA
| | - Chiara Orlandi
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Microbiology and Immunology of the University of Maryland School of Medicine, Baltimore, USA
| | - Jonathan Richard
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, Quebec, Canada
| | - Shilei Ding
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, Quebec, Canada
| | - Xishan Chen
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Biochemistry and Molecular Biology, the University of Maryland School of Medicine, Baltimore, USA
| | - Daniel A Bonsor
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Division of Basic Science of the Institute of Human Virology and Department of Medicine of the University of Maryland School of Medicine, Baltimore, USA
| | - Eric J Sundberg
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Microbiology and Immunology of the University of Maryland School of Medicine, Baltimore, USA.,Division of Basic Science of the Institute of Human Virology and Department of Medicine of the University of Maryland School of Medicine, Baltimore, USA
| | - Wuyuan Lu
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Biochemistry and Molecular Biology, the University of Maryland School of Medicine, Baltimore, USA
| | - Krishanu Ray
- Department of Biochemistry and Molecular Biology, the University of Maryland School of Medicine, Baltimore, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, Quebec, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - George K Lewis
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Microbiology and Immunology of the University of Maryland School of Medicine, Baltimore, USA
| | - Marzena Pazgier
- Division of Vaccine Research of Institute of Human Virology, the University of Maryland School of Medicine, Baltimore, USA.,Department of Biochemistry and Molecular Biology, the University of Maryland School of Medicine, Baltimore, USA
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24
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Overcoming the Constraints of Anti-HIV/CD89 Bispecific Antibodies That Limit Viral Inhibition. J Immunol Res 2016; 2016:9425172. [PMID: 27419146 PMCID: PMC4933884 DOI: 10.1155/2016/9425172] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 05/09/2016] [Accepted: 05/22/2016] [Indexed: 01/01/2023] Open
Abstract
Innovative strategies are necessary to maximize the clinical application of HIV neutralizing antibodies. To this end, bispecific constructs of human antibody F240, reactive with well-conserved gp41 epitope and antibody 14A8, reactive with the IgA receptor (CD89) on effector cells, were constructed. A F240 × 14A8 bispecific single chain variable region (scFv) molecule was constructed by linking two scFvs using a conventional GGGGS linker. Despite immunoreactivity with HIV gp41 and neutrophils, this bispecific scFv failed to inhibit HIV infection. This is in sharp contrast to viral inhibition using a chemical conjugate of the Fab of these two antibodies. Therefore, we constructed two novel Fab-like bispecific antibody molecules centered on fusion of the IgG1 CH1 domain or CH1-hinge domain to the C-terminus of F240scFv and fusion of the kappa chain CL domain to the C-terminus of 14A8scFv. Both Bi-Fab antibodies showed significant ADCVI activity for multiple clade B and clade C isolates by arming the neutrophils to inhibit HIV infection. The approach presented in this study is unique for HIV immunotherapy in that the impetus of neutralization is to arm and mobilize PMN to destroy HIV and HIV infected cells.
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25
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Comparison of Antibody-Dependent Cell-Mediated Cytotoxicity and Virus Neutralization by HIV-1 Env-Specific Monoclonal Antibodies. J Virol 2016; 90:6127-6139. [PMID: 27122574 DOI: 10.1128/jvi.00347-16] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/16/2016] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED Although antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FL or SHIVAD8-EO ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection. IMPORTANCE This study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.
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Mason RD, Welles HC, Adams C, Chakrabarti BK, Gorman J, Zhou T, Nguyen R, O’Dell S, Lusvarghi S, Bewley CA, Li H, Shaw GM, Sheng Z, Shapiro L, Wyatt R, Kwong PD, Mascola JR, Roederer M. Targeted Isolation of Antibodies Directed against Major Sites of SIV Env Vulnerability. PLoS Pathog 2016; 12:e1005537. [PMID: 27064278 PMCID: PMC4827850 DOI: 10.1371/journal.ppat.1005537] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 03/09/2016] [Indexed: 11/26/2022] Open
Abstract
The simian immunodeficiency virus (SIV) challenge model of lentiviral infection is often used as a model to human immunodeficiency virus type 1 (HIV-1) for studying vaccine mediated and immune correlates of protection. However, knowledge of the structure of the SIV envelope (Env) glycoprotein is limited, as is knowledge of binding specificity, function and potential efficacy of SIV antibody responses. In this study we describe the use of a competitive probe binding sort strategy as well as scaffolded probes for targeted isolation of SIV Env-specific monoclonal antibodies (mAbs). We isolated nearly 70 SIV-specific mAbs directed against major sites of SIV Env vulnerability analogous to broadly neutralizing antibody (bnAb) targets of HIV-1, namely, the CD4 binding site (CD4bs), CD4-induced (CD4i)-site, peptide epitopes in variable loops 1, 2 and 3 (V1, V2, V3) and potentially glycan targets of SIV Env. The range of SIV mAbs isolated includes those exhibiting varying degrees of neutralization breadth and potency as well as others that demonstrated binding but not neutralization. Several SIV mAbs displayed broad and potent neutralization of a diverse panel of 20 SIV viral isolates with some also neutralizing HIV-27312A. This extensive panel of SIV mAbs will facilitate more effective use of the SIV non-human primate (NHP) model for understanding the variables in development of a HIV vaccine or immunotherapy. An antibody-based approach targeting human immunodeficiency virus (HIV) envelope (Env) protein may eventually prove to be effective in treating or preventing HIV infection. However, before any candidate HIV treatment or vaccine can be tested in humans, it must first be evaluated in nonhuman primates (NHPs)–the closest living relatives to humans. Simian immunodeficiency virus (SIV) is the closest available non-chimeric virus—NHP model for studying and testing HIV vaccines or therapies. The SIV model complements the simian-human immunodeficiency virus (SHIV) model in distinctive ways, although less is known about SIV Env-specific antibody responses in NHPs. There are several sites on HIV Env that are vulnerable to antibody-mediated protection, and here we isolated and analyzed monoclonal antibodies (mAbs) from NHPs targeting analogous sites on SIV Env. In particular, we studied mAbs for their ability to bind the viral Env protein and to block infection of cells by widely divergent strains of SIV. These well-characterized SIV Env-specific antibodies will allow for more thorough NHP pre-clinical testing of various antibody-based SIV/HIV vaccine and immunotherapeutic strategies before proceeding to human clinical trials and may yield unanticipated findings relating to molecular mechanisms underlying the unusual breadth of neutralization observed in HIV-2 infection.
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Affiliation(s)
- Rosemarie D. Mason
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
- * E-mail: (RDM); (MR)
| | - Hugh C. Welles
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Cameron Adams
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Bimal K. Chakrabarti
- International AIDS Vaccine Initiative (IAVI) HIV Vaccine Design Program, Translational Health Science and Technology Institute, Haryana, India
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Tongqing Zhou
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Richard Nguyen
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Sijy O’Dell
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Sabrina Lusvarghi
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Carole A. Bewley
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Hui Li
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - George M. Shaw
- Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zizhang Sheng
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, New York, United States of America
| | - Lawrence Shapiro
- Department of Biochemistry and Molecular Biophysics and Department of Systems Biology, Columbia University, New York, New York, United States of America
| | - Richard Wyatt
- IAVI Neutralizing Antibody Center, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Peter D. Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - John R. Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Mario Roederer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
- * E-mail: (RDM); (MR)
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Janda A, Bowen A, Greenspan NS, Casadevall A. Ig Constant Region Effects on Variable Region Structure and Function. Front Microbiol 2016; 7:22. [PMID: 26870003 PMCID: PMC4740385 DOI: 10.3389/fmicb.2016.00022] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/11/2016] [Indexed: 01/02/2023] Open
Abstract
The adaptive humoral immune response is responsible for the generation of antimicrobial proteins known as immunoglobulin molecules or antibodies. Immunoglobulins provide a defense system against pathogenic microbes and toxins by targeting them for removal and/or destruction. Historically, antibodies have been thought to be composed of distinct structural domains known as the variable and constant regions that are responsible for antigen binding and mediating effector functions such as opsonization and complement activation, respectively. These domains were thought to be structurally and functionally independent. Recent work has revealed however, that in some families of antibodies, the two regions can influence each other. We will discuss the body of work that led to these observations, as well as the mechanisms that have been proposed to explain how these two different antibody regions may interact in the function of antigen binding.
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Affiliation(s)
- Alena Janda
- Department of Microbiology and Immunology, Albert Einstein College of Medicine New York, NY, USA
| | - Anthony Bowen
- Department of Microbiology and Immunology, Albert Einstein College of Medicine New York, NY, USA
| | - Neil S Greenspan
- Department of Pathology, Case Western Reserve University Cleveland, OH, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health Baltimore, MD, USA
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AlSalmi W, Mahalingam M, Ananthaswamy N, Hamlin C, Flores D, Gao G, Rao VB. A New Approach to Produce HIV-1 Envelope Trimers: BOTH CLEAVAGE AND PROPER GLYCOSYLATION ARE ESSENTIAL TO GENERATE AUTHENTIC TRIMERS. J Biol Chem 2015; 290:19780-95. [PMID: 26088135 PMCID: PMC4528139 DOI: 10.1074/jbc.m115.656611] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Indexed: 12/22/2022] Open
Abstract
The trimeric envelope spike of HIV-1 mediates virus entry into human cells. The exposed part of the trimer, gp140, consists of two noncovalently associated subunits, gp120 and gp41 ectodomain. A recombinant vaccine that mimics the native trimer might elicit entry-blocking antibodies and prevent virus infection. However, preparation of authentic HIV-1 trimers has been challenging. Recently, an affinity column containing the broadly neutralizing antibody 2G12 has been used to capture recombinant gp140 and prepare trimers from clade A BG505 that naturally produces stable trimers. However, this antibody-based approach may not be as effective for the diverse HIV-1 strains with different epitope signatures. Here, we report a new and simple approach to produce HIV-1 envelope trimers. The C terminus of gp140 was attached to Strep-tag II with a long linker separating the tag from the massive trimer base and glycan shield. This allowed capture of nearly homogeneous gp140 directly from the culture medium. Cleaved, uncleaved, and fully or partially glycosylated trimers from different clade viruses were produced. Extensive biochemical characterizations showed that cleavage of gp140 was not essential for trimerization, but it triggered a conformational change that channels trimers into correct glycosylation pathways, generating compact three-blade propeller-shaped trimers. Uncleaved trimers entered aberrant pathways, resulting in hyperglycosylation, nonspecific cross-linking, and conformational heterogeneity. Even the cleaved trimers showed microheterogeneity in gp41 glycosylation. These studies established a broadly applicable HIV-1 trimer production system as well as generating new insights into their assembly and maturation that collectively bear on the HIV-1 vaccine design.
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Affiliation(s)
- Wadad AlSalmi
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Marthandan Mahalingam
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Neeti Ananthaswamy
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Christopher Hamlin
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Dalia Flores
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Guofen Gao
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
| | - Venigalla B Rao
- From the Department of Biology, The Catholic University of America, Washington, D. C. 20064
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Mengistu M, Ray K, Lewis GK, DeVico AL. Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells. PLoS Pathog 2015; 11:e1004772. [PMID: 25807494 PMCID: PMC4373872 DOI: 10.1371/journal.ppat.1004772] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 03/02/2015] [Indexed: 12/17/2022] Open
Abstract
The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step. The elucidation of these epitope exposure patterns during viral entry will help clarify antibody-mediated inhibition of HIV-1 as it is measured in vitro and in vivo. A major strategy for blocking HIV-1 infection is to target antiviral antibodies or drugs to sites of vulnerability on the surface proteins of the virus. It is a relatively straightforward matter to explore these sites on the surfaces of free HIV-1 particles or on isolated viral envelope antigens. However, one difficulty presented by HIV-1 is that its surface proteins are flexible and change shape once the virus has attached to its host cell. To date, it has been difficult to predict how cell-bound HIV-1 exposes its sites of vulnerability. Yet the antiviral activities of certain antibodies indirectly suggest that there must be unique sites on cell-bound HIV-1 that are not found on free virus. Here, we use new techniques and tools to determine how HIV-1 exposes unique sites of vulnerability after attaching to host cells. We find that the virus exposes a remarkable array of these sites, including ones previously believed hidden. These exposure patterns explain the antiviral activities of various anti-HIV-1 antibodies and provide a new view of how HIV-1 might interact with the immune system. Our study also provides insights for how to target HIV-1 with antiviral antibodies, vaccines, or antiviral agents.
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Affiliation(s)
- Meron Mengistu
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (MM); (ALD)
| | - Krishanu Ray
- Center for Fluorescence Spectroscopy of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - George K. Lewis
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Anthony L. DeVico
- The Institute of Human Virology of the University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (MM); (ALD)
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What Do Chaotrope-Based Avidity Assays for Antibodies to HIV-1 Envelope Glycoproteins Measure? J Virol 2015; 89:5981-95. [PMID: 25810537 DOI: 10.1128/jvi.00320-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 03/16/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED When HIV-1 vaccine candidates that include soluble envelope glycoproteins (Env) are tested in humans and other species, the resulting antibody responses to Env are sifted for correlates of protection or risk. One frequently used assay measures the reduction in antibody binding to Env antigens by an added chaotrope (such as thiocyanate). Based on that assay, an avidity index was devised for assessing the affinity maturation of antibodies of unknown concentration in polyclonal sera. Since a high avidity index was linked to protection in animal models of HIV-1 infection, it has become a criterion for evaluating antibody responses to vaccine candidates. But what does the assay measure and what does an avidity index mean? Here, we have used a panel of monoclonal antibodies to well-defined epitopes on Env (gp120, gp41, and SOSIP.664 trimers) to explore how the chaotrope acts. We conclude that the chaotrope sensitivity of antibody binding to Env depends on several properties of the epitopes (continuity versus tertiary- and quaternary-structural dependence) and that the avidity index has no simple relationship to antibody affinity for functional Env spikes on virions. We show that the binding of broadly neutralizing antibodies against quaternary-structural epitopes is particularly sensitive to chaotrope treatment, whereas antibody binding to epitopes in variable loops and to nonneutralization epitopes in gp41 is generally resistant. As a result of such biases, the avidity index may at best be a mere surrogate for undefined antibody or other immune responses that correlate weakly with protection. IMPORTANCE An effective HIV-1 vaccine is an important goal. Such a vaccine will probably need to induce antibodies that neutralize typically transmitted variants of HIV-1, preventing them from infecting target cells. Vaccine candidates have so far failed to induce such antibody responses, although some do protect weakly against infection in animals and, possibly, humans. In the search for responses associated with protection, an avidity assay based on chemical disruption is often used to measure the strength of antibody binding. We have analyzed this assay mechanistically and found that the epitope specificity of an antibody has a greater influence on the outcome than does its affinity. As a result, the avidity assay is biased toward the detection of some antibody specificities while disfavoring others. We conclude that the assay may yield merely indirect correlations with weak protection, specifically when Env vaccination has failed to induce broad neutralizing responses.
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Borthwick NJ, Rosario M, Schiffner T, Bowles E, Ahmed T, Liljeström P, Stewart-Jones GE, Drijfhout JW, Melief CJM, Hanke T. Humoral responses to HIVconsv induced by heterologous vaccine modalities in rhesus macaques. IMMUNITY INFLAMMATION AND DISEASE 2015; 3:82-93. [PMID: 26029368 PMCID: PMC4444151 DOI: 10.1002/iid3.52] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/27/2015] [Accepted: 01/28/2015] [Indexed: 12/17/2022]
Abstract
Vaccines delivering T cell immunogen HIVconsv vectored by plasmid DNA, non-replicating simian adenovirus and non-replicating modified vaccinia virus Ankara (MVA) are under clinical evaluation in phase I/IIa trials in UK, Europe, and Africa. While these vaccines aim to induce effector T cell responses specific for HIV-1, we here characterized the humoral responses induced by HIVconsv administration to macaques using six different vaccine modalities: plasmid DNA, human adenovirus serotype 5, simian adenovirus serotype 63, MVA, Semliki Forest virus replicons, and adjuvanted overlapping synthetic long peptides (SLP). We found that only the SLP formulation, but none of the genetic vaccine platforms induced antibodies recognizing linear HIVconsv epitopes, median 32/46 SLP.HIVconsv peptides. These antibodies bound to 15-mer and SLP peptides, recombinant gp120 and trimeric gp140 of HIV-1 Bal, YU2, JRFL, and UG037, but failed to react with HIV-1 Bal and IIIB virions and HIV-1 Bal- and IIIB-infected human cells, and consequently failed to induce neutralizing antibodies. The HIVconsv immunogen contains conserved regions derived from Gag, Pol, Vif, and Env proteins of HIV-1, and antibodies induced by the SLP.HIVconsv vaccination resulted in positive signals in routine HIV-1 tests. Thus, only HIVconsv delivered by SLP resulted in seroconversion, an observation that provides important guidance for recruiting volunteers into future clinical trials. Furthermore, our data confirms that vaccine delivery by SLP induces humoral as well as cellular immune responses and could be considered for inclusion in future vaccine regimens where this is required.
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Affiliation(s)
- Nicola J Borthwick
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive Oxford, OX3 7DQ, UK
| | - Maximillian Rosario
- Nuffield Department of Medicine, MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Oxford, OX3 9DS, UK
| | - Torben Schiffner
- Nuffield Department of Medicine, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road Oxford, OX1 3RE, UK
| | - Emma Bowles
- Nuffield Department of Medicine, MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Oxford, OX3 9DS, UK
| | - Tina Ahmed
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive Oxford, OX3 7DQ, UK
| | - Peter Liljeström
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet Stockholm, Sweden
| | - Guillaume E Stewart-Jones
- Nuffield Department of Medicine, MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Oxford, OX3 9DS, UK
| | - Jan W Drijfhout
- Departement of Immunohematology and Blood Transfusion, Leiden University Medical Centre Leiden, the Netherlands
| | - Cornelis J M Melief
- Departement of Immunohematology and Blood Transfusion, Leiden University Medical Centre Leiden, the Netherlands
| | - Tomáš Hanke
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive Oxford, OX3 7DQ, UK ; Nuffield Department of Medicine, MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Oxford, OX3 9DS, UK
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Yasmeen A, Ringe R, Derking R, Cupo A, Julien JP, Burton DR, Ward AB, Wilson IA, Sanders RW, Moore JP, Klasse PJ. Differential binding of neutralizing and non-neutralizing antibodies to native-like soluble HIV-1 Env trimers, uncleaved Env proteins, and monomeric subunits. Retrovirology 2014; 11:41. [PMID: 24884783 PMCID: PMC4067080 DOI: 10.1186/1742-4690-11-41] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/14/2014] [Indexed: 12/13/2022] Open
Abstract
Background The trimeric envelope glycoproteins (Env) on the surface of HIV-1 virions are the targets for neutralizing antibodies (NAbs). No candidate HIV-1 immunogen has yet induced potent, broadly active NAbs (bNAbs). Part of the explanation may be that previously tested Env proteins inadequately mimic the functional, native Env complex. Trimerization and the proteolytic processing of Env precursors into gp120 and gp41 profoundly alter antigenicity, but soluble cleaved trimers are too unstable to serve as immunogens. By introducing stabilizing mutations (SOSIP), we constructed soluble, cleaved Env trimers derived from the HIV-1 subtype A isolate BG505 that resemble native Env spikes on virions both structurally and antigenically. Results We used surface plasmon resonance (SPR) to quantify antibody binding to different forms of BG505 Env: the proteolytically cleaved SOSIP.664 trimers, cleaved gp120-gp41ECTO protomers, and gp120 monomers. Non-NAbs to the CD4-binding site bound only marginally to the trimers but equally well to gp120-gp41ECTO protomers and gp120 monomers, whereas the bNAb VRC01, directed to the CD4bs, bound to all three forms. In contrast, bNAbs to V1V2 glycan-dependent epitopes bound preferentially (PG9 and PG16) or exclusively (PGT145) to trimers. We also explored the antigenic consequences of three different features of SOSIP.664 gp140 trimers: the engineered inter-subunit disulfide bond, the trimer-stabilizing I559P change in gp41ECTO, and proteolytic cleavage at the gp120-gp41ECTO junction. Each of these three features incrementally promoted native-like trimer antigenicity. We compared Fab and IgG versions of bNAbs and validated a bivalent model of IgG binding. The NAbs showed widely divergent binding kinetics and degrees of binding to native-like BG505 SOSIP.664. High off-rate constants and low stoichiometric estimates of NAb binding were associated with large amounts of residual infectivity after NAb neutralization of the corresponding BG505.T332N pseudovirus. Conclusions The antigenicity and structural integrity of cleaved BG505 SOSIP.664 trimers render these proteins good mimics of functional Env spikes on virions. In contrast, uncleaved gp140s antigenically resemble individual gp120-gp41ECTO protomers and gp120 monomers, but not native trimers. Although NAb binding to functional trimers may thus be both necessary and sufficient for neutralization, the kinetics and stoichiometry of the interaction influence the neutralizing efficacy of individual NAbs.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Per Johan Klasse
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, USA.
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Grover RK, Zhu X, Nieusma T, Jones T, Boreo I, MacLeod AS, Mark A, Niessen S, Kim HJ, Kong L, Assad-Garcia N, Kwon K, Chesi M, Smider VV, Salomon DR, Jelinek DF, Kyle RA, Pyles RB, Glass JI, Ward AB, Wilson IA, Lerner RA. A structurally distinct human mycoplasma protein that generically blocks antigen-antibody union. Science 2014; 343:656-661. [PMID: 24503852 PMCID: PMC3987992 DOI: 10.1126/science.1246135] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report the discovery of a broadly reactive antibody-binding protein (Protein M) from human mycoplasma. The crystal structure of the ectodomain of transmembrane Protein M differs from other known protein structures, as does its mechanism of antibody binding. Protein M binds with high affinity to all types of human and nonhuman immunoglobulin G, predominantly through attachment to the conserved portions of the variable region of the κ and λ light chains. Protein M blocks antibody-antigen union, likely because of its large C-terminal domain extending over the antibody-combining site, blocking entry to large antigens. Similar to the other immunoglobulin-binding proteins such as Protein A, Protein M as well as its orthologs in other Mycoplasma species could become invaluable reagents in the antibody field.
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Affiliation(s)
- Rajesh K. Grover
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xueyong Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Travis Nieusma
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Teresa Jones
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Isabel Boreo
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Amanda S. MacLeod
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Adam Mark
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sherry Niessen
- The Center for Physiological Proteomics, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Helen J. Kim
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Leopold Kong
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Nacyra Assad-Garcia
- Synthetic Biology and Bioenergy Group, J Craig Venter Research Institute, Rockville, MD 20850, USA
| | - Keehwan Kwon
- Synthetic Biology and Bioenergy Group, J Craig Venter Research Institute, Rockville, MD 20850, USA
| | - Marta Chesi
- Comprehensive Cancer Center, Mayo Clinic Arizona, Scottsdale, AZ 85259, USA
| | - Vaughn V. Smider
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Daniel R. Salomon
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Diane F. Jelinek
- Department of Internal Medicine, Division of Hematology, and Department of Immunology, Mayo Clinic, College of Medicine, Rochester, MN 55905, USA
| | - Robert A. Kyle
- Department of Internal Medicine, Division of Hematology, and Department of Immunology, Mayo Clinic, College of Medicine, Rochester, MN 55905, USA
| | - Richard B. Pyles
- Departments of Pediatrics and Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - John I. Glass
- Synthetic Biology and Bioenergy Group, J Craig Venter Research Institute, Rockville, MD 20850, USA
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Richard A. Lerner
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
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Abstract
The structural flexibility found in human immunodeficiency virus (HIV) envelope glycoproteins creates a complex relationship between antigenicity and sensitivity to antiviral antibodies. The study of this issue in the context of viral particles is particularly problematic as conventional virus capture approaches can perturb antigenicity profiles. Here, we employed a unique analytical system based on fluorescence correlation spectroscopy (FCS), which measures antibody-virion binding with all reactants continuously in solution. Panels of nine anti-envelope monoclonal antibodies (MAbs) and five virus types were used to connect antibody binding profiles with neutralizing activities. Anti-gp120 MAbs against the 2G12 or b12 epitope, which marks functional envelope structures, neutralized viruses expressing CCR5-tropic envelopes and exhibited efficient virion binding in solution. MAbs against CD4-induced (CD4i) epitopes considered hidden on functional envelope structures poorly bound these viruses and were not neutralizing. Anti-gp41 MAb 2F5 was neutralizing despite limited virion binding. Similar antigenicity patterns occurred on CXCR4-tropic viruses, except that anti-CD4i MAbs 17b and 19e were neutralizing despite little or no virion binding. Notably, anti-gp120 MAb PG9 and anti-gp41 MAb F240 bound to both CCR5-tropic and CXCR4-tropic viruses without exerting neutralizing activity. Differences in the virus production system altered the binding efficiencies of some antibodies but did not enhance antigenicity of aberrant gp120 structures. Of all viruses tested, only JRFL pseudoviruses showed a direct relationship between MAb binding efficiency and neutralizing potency. Collectively, these data indicate that the antigenic profiles of free HIV particles generally favor the exposure of functional over aberrant gp120 structures. However, the efficiency of virion-antibody interactions in solution inconsistently predicts neutralizing activity in vitro.
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Adaptation to the interferon-induced antiviral state by human and simian immunodeficiency viruses. J Virol 2013; 87:3549-60. [PMID: 23325684 DOI: 10.1128/jvi.03219-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The production of type I interferon (IFN) is an early host response to different infectious agents leading to the induction of hundreds of IFN-stimulated genes (ISGs). The roles of many ISGs in host defense are unknown, but their expression results in the induction of an "antiviral state" that inhibits the replication of many viruses. Here we show that prototype primate lentiviruses human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus of macaques (SIV(MAC) and SIV(MNE)) can replicate in lymphocytes from their usual hosts (humans and macaques, respectively), even when an antiviral state is induced by IFN-α treatment. In contrast, HIV-1 and SIV(MAC)/SIV(MNE) replication was hypersensitive to IFN-α in lymphocytes from unnatural hosts, indicating that the antiviral state can effectively curtail the replication of primate lentiviruses in hosts to which they are not adapted. Most of the members of a panel of naturally occurring HIV-1 and HIV-2 strains behaved like prototype strains and were comparatively insensitive to IFN-α in human lymphocytes. Using chimeric viruses engineered to overcome restriction factors whose antiretroviral specificities vary in a species-dependent manner, we demonstrate that differential HIV-1 and SIV(MAC) sensitivities to IFN-α in lymphocytes from humans and macaques could not be ascribed to TRIM5, APOBEC3, tetherin, or SAMHD1. Single-cycle infection experiments indicated that at least part of this species-specific, IFN-α-induced restriction of primate lentivirus replication occurs early in the retroviral life cycle. Overall, these studies indicate the existence of undiscovered, IFN-α-inducible antiretroviral factors whose spectrum of activity varies in a species-dependent manner and to which at least some HIV/SIV strains have become adapted in their usual hosts.
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Limited or no protection by weakly or nonneutralizing antibodies against vaginal SHIV challenge of macaques compared with a strongly neutralizing antibody. Proc Natl Acad Sci U S A 2011; 108:11181-6. [PMID: 21690411 DOI: 10.1073/pnas.1103012108] [Citation(s) in RCA: 215] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To guide vaccine design, we assessed whether human monoclonal antibodies (MAbs) b12 and b6 against the CD4 binding site (CD4bs) on HIV-1 gp120 and F240 against an immundominant epitope on gp41 could prevent vaginal transmission of simian HIV (SHIV)-162P4 to macaques. The two anti-gp120 MAbs have similar monomeric gp120-binding properties, measured in vitro, but b12 is strongly neutralizing and b6 is not. F240 is nonneutralizing. Applied vaginally at a high dose, the strongly neutralizing MAb b12 provided sterilizing immunity in seven of seven animals, b6 in zero of five animals, and F240 in two of five animals. Compared with control animals, the protection by b12 achieved statistical significance, whereas that caused by F240 did not. For two of three unprotected F240-treated animals there was a trend toward lowered viremia. The potential protective effect of F240 may relate to the relatively strong ability of this antibody to capture infectious virions. Additional passive transfer experiments also indicated that the ability of the administered anti-gp120 MAbs to neutralize the challenge virus was a critical influence on protection. Furthermore, when data from all of the experiments were combined, there was a significant increase in the number of founder viruses establishing infection in animals receiving MAb b6, compared with other nonprotected macaques. Thus, a gp120-binding, weakly neutralizing MAb to the CD4bs was, at best, completely ineffective at protection. A nonneutralizing antibody to gp41 may have a limited capacity to protect, but the results suggest that the central focus of HIV-1 vaccine research should be on the induction of potently neutralizing antibodies.
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Leaman DP, Kinkead H, Zwick MB. In-solution virus capture assay helps deconstruct heterogeneous antibody recognition of human immunodeficiency virus type 1. J Virol 2010; 84:3382-95. [PMID: 20089658 PMCID: PMC2838137 DOI: 10.1128/jvi.02363-09] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 01/06/2010] [Indexed: 01/27/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) on whole virions is heterogeneous, so molecular analysis of Env with monoclonal antibodies (MAbs) is challenging. Virus capture assays (VCAs) involving immobilized MAbs are typically used, but these assays suffer from immobilization artifacts and do not provide binding constants. Furthermore, we show here that certain HIV-1 neutralizing MAbs, including 2G12, 4E10, 2F5, Z13e1, and D5, will capture virion particles completely devoid of Env. We modified the VCA such that MAbs and virions are incubated in solution, and unbound MAbs are removed prior to the capture step. This modification nearly eliminated evidence of Env-independent binding by MAbs to virions and allowed determination of apparent affinity constants in solution. Three important qualitative observations were further revealed. First, neutralizing MAbs 2F5, 4E10, and Z13e1 against the membrane-proximal external region (MPER) of HIV-1 gp41 were found to capture virions efficiently only if a significant amount of uncleaved gp160 or synthetic MPER peptide was present. Second, we show how non-native forms of Env vary by Env genotype and that Env from HIV-1(JR-FL) is more homogeneously trimeric than that from HIV-1(JR-CSF). Third, we determined that Env containing all or parts of gp41, including uncleaved gp160, binds spontaneously to free virions. This exogenous Env is an indiscriminate molecular "bridge" between Env-specific Ab and virions and can affect VCA analyses, particularly using pseudotyped virions. Heterogeneity in Env from endogenous and exogenous sources might also subvert humoral immunity to HIV-1, so in-solution VCAs may help to dissect this heterogeneity for vaccine design purposes.
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Affiliation(s)
- Daniel P. Leaman
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037
| | - Heather Kinkead
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037
| | - Michael B. Zwick
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037
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38
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Lucchese A, Serpico R, Crincoli V, Shoenfeld Y, Kanduc D. Sequence Uniqueness as a Molecular Signature of HIV-1-Derived B-Cell Epitopes. Int J Immunopathol Pharmacol 2009; 22:639-46. [DOI: 10.1177/039463200902200309] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The complex pathophysiology of human immunodeficiency virus (HIV) infection and the relatively high mutation rate of the retrovirus make it challenging to design effective anti-HIV vaccines. Several attempts have been made during the last decades to elucidate the enigmatic immunology of HIV infection and to predict potential immunogenic peptides for active vaccination using bioinformatic analysis methods. The results obtained to date to address this important problem are scarce. In this study, we exploit available HIV databases and analyse previously characterized HIV-encoded linear B-cell epitopes for their amino acid sequence similarity to the human or murine host proteome. We obtained further documentation that the HIV-derived antibody-targeted sequences mostly coincide with peptide areas rarely shared with the host proteins. In toto, our past and present data give clear-cut support to the statement that low-similarity to the host proteome is a major mechanism in defining viral peptide immunogenicity and indicate a possible way for inducing effective, high-titer, and non-cross-reactive antibodies to be used in anti-HIV vaccine therapy.
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Affiliation(s)
| | | | - V. Crincoli
- Department of Odontostomatology and Surgery, University of Bari, Italy
| | - Y. Shoenfeld
- Center for Autoimmune Diseases, Department of Medicine ‘B’, Sheba Medical Center, Israel and Sackler Faculty of Medicine, Tel-Aviv University, Israel
| | - D. Kanduc
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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39
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Utilization of immunoglobulin G Fc receptors by human immunodeficiency virus type 1: a specific role for antibodies against the membrane-proximal external region of gp41. J Virol 2009; 83:7397-410. [PMID: 19458010 DOI: 10.1128/jvi.00656-09] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Receptors (FcgammaRs) for the constant region of immunoglobulin G (IgG) are an important link between humoral immunity and cellular immunity. To help define the role of FcgammaRs in determining the fate of human immunodeficiency virus type 1 (HIV-1) immune complexes, cDNAs for the four major human Fcgamma receptors (FcgammaRI, FcgammaRIIa, FcgammaRIIb, and FcgammaRIIIa) were stably expressed by lentiviral transduction in a cell line (TZM-bl) commonly used for standardized assessments of HIV-1 neutralization. Individual cell lines, each expressing a different FcgammaR, bound human IgG, as evidence that the physical properties of the receptors were preserved. In assays with a HIV-1 multisubtype panel, the neutralizing activities of two monoclonal antibodies (2F5 and 4E10) that target the membrane-proximal external region (MPER) of gp41 were potentiated by FcgammaRI and, to a lesser extent, by FcgammaRIIb. Moreover, the neutralizing activity of an HIV-1-positive plasma sample known to contain gp41 MPER-specific antibodies was potentiated by FcgammaRI. The neutralizing activities of monoclonal antibodies b12 and 2G12 and other HIV-1-positive plasma samples were rarely affected by any of the four FcgammaRs. Effects with gp41 MPER-specific antibodies were moderately stronger for IgG1 than for IgG3 and were ineffective for Fab. We conclude that FcgammaRI and FcgammaRIIb facilitate antibody-mediated neutralization of HIV-1 by a mechanism that is dependent on the Fc region, IgG subclass, and epitope specificity of antibody. The FcgammaR effects seen here suggests that the MPER of gp41 could have greater value for vaccines than previously recognized.
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40
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Yuan W, Li X, Kasterka M, Gorny MK, Zolla-Pazner S, Sodroski J. Oligomer-specific conformations of the human immunodeficiency virus (HIV-1) gp41 envelope glycoprotein ectodomain recognized by human monoclonal antibodies. AIDS Res Hum Retroviruses 2009; 25:319-28. [PMID: 19292593 DOI: 10.1089/aid.2008.0213] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Trimerization of the human immunodeficiency virus (HIV-1) envelope glycoproteins is mediated by the ectodomain of the gp41 transmembrane glycoprotein. Here we investigate oligomer-specific conformations of gp41 by using monoclonal antibodies (MAbs) from HIV-1-infected humans. Human MAbs directed against the cluster I region of gp41 recognized trimeric, dimeric, and monomeric forms of soluble envelope glycoproteins; thus, the integrity of the cluster I epitopes is minimally affected by the oligomeric state. In contrast, human MAbs to the cluster II region were all oligomers specific. One cluster II MAb, 126-6, recognized exclusively the trimeric form of envelope glycoproteins, whereas the others recognized both trimeric and dimeric forms. Thus, a distinct trimer-specific conformation exists in the cluster II region of gp41. Analysis of soluble envelope glycoprotein mutants revealed that gp41 sequences immediately N-terminal to isoleucine 646 contribute to the formation of both the trimer and the trimer-specific conformational epitope.
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Affiliation(s)
- Wen Yuan
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia 22908
| | - Xing Li
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
- Department of Pathology, Division of AIDS, Harvard Medical School, Boston, Massachusetts 02115
| | - Marta Kasterka
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Miroslaw K. Gorny
- Department of Pathology, New York University School of Medicine, New York, New York 10016
| | - Susan Zolla-Pazner
- Department of Pathology, New York University School of Medicine, New York, New York 10016
- Veterans Affairs Medical Center, New York, New York 10010
| | - Joseph Sodroski
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
- Department of Pathology, Division of AIDS, Harvard Medical School, Boston, Massachusetts 02115
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115
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41
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Dey AK, David KB, Lu M, Moore JP. Biochemical and biophysical comparison of cleaved and uncleaved soluble, trimeric HIV-1 envelope glycoproteins. Virology 2009; 385:275-81. [PMID: 19135223 DOI: 10.1016/j.virol.2008.12.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Revised: 11/20/2008] [Accepted: 12/03/2008] [Indexed: 01/23/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) entry into host cells is mediated by the trimeric envelope glycoprotein complex (Env). Accordingly, the Env proteins are the targets for neutralizing antibodies (NAbs) and are the focus of vaccines intended to induce NAbs. Because the Env complex is labile, soluble recombinant Env (gp140) trimers require engineering to stabilize them sufficiently for use as immunogens. Trimeric forms of gp140 trimers can be created that are either cleavage-competent or cleavage-defective at the junction between the gp120 and gp41 subunits. As functional trimers are cleaved at this site, the question arises as to whether cleavage affects the antigenic structure of the Env complex in a way that is relevant to vaccine design. Here, we present a comparative analysis of the antigenicity profiles of cleaved and uncleaved gp140 trimers derived from the KNH1144 (subtype A) virus that are otherwise closely sequence-matched. While cleavage did not affect the exposure of NAb epitopes on the gp140 trimers, non-neutralizing antibodies to gp41 epitopes bound much more strongly to uncleaved trimers. Hence cleavage does alter the structure of the HIV-1 Env complex.
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Affiliation(s)
- Antu K Dey
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10021, USA
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42
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Gorny MK, Wang XH, Williams C, Volsky B, Revesz K, Witover B, Burda S, Urbanski M, Nyambi P, Krachmarov C, Pinter A, Zolla-Pazner S, Nadas A. Preferential use of the VH5-51 gene segment by the human immune response to code for antibodies against the V3 domain of HIV-1. Mol Immunol 2008; 46:917-26. [PMID: 18952295 DOI: 10.1016/j.molimm.2008.09.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 09/08/2008] [Indexed: 12/29/2022]
Abstract
Human anti-V3 monoclonal antibodies (mAbs) generated from HIV-1 infected individuals display diversity in the range of their cross-neutralization that may be related to their immunogenetic background. The study of the immunoglobulin (Ig) variable region gene usage of heavy chains have shown a preferential usage of the VH5-51 gene segment which was detected in 35% of 51 human anti-V3 mAbs. In contrast, human mAbs against other envelope regions of HIV-1 (anti-Env), including the CD4-binding domain, the CD4-induced epitope, and gp41 preferentially used the VH1-69 gene segment, and none of them used the VH5-51 gene. Furthermore, the usage of the VH4 family by anti-V3 mAbs was restricted to only one gene segment, VH4-59, while the VH3 gene family was used at a significantly lower frequency by all of the analyzed anti-HIV-1 mAbs. Multivariate analysis showed that usage of VH gene segments was significantly different between anti-V3 and anti-Env mAbs, and compared to antibodies from healthy subjects. In addition, the anti-V3 mAbs preferentially used the JH3 and D2-15 gene segments. The preferential usage of selected Ig gene segments and the characteristic pattern of Ig gene usage by anti-V3 mAbs can be related to the conserved structure of the V3 region.
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Affiliation(s)
- Miroslaw K Gorny
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA. mirek@
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43
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A bispecific antibody composed of a nonneutralizing antibody to the gp41 immunodominant region and an anti-CD89 antibody directs broad human immunodeficiency virus destruction by neutrophils. J Virol 2008; 82:4671-4. [PMID: 18272577 DOI: 10.1128/jvi.02499-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In addition to the direct neutralization of virus, there is a broader potential for antibody-mediated inhibition of human immunodeficiency virus (HIV) by targeting HIV to effector cells. We demonstrate here that a bispecific antibody incorporating a broadly reactive anti-gp41 antibody, F240, and an anti-IgA receptor (CD89) antibody is effective at directing neutrophils to destroy HIV. Not only are neutrophils the predominant type of white blood cells and very efficient at mediating cell cytotoxicity, they are relatively resistant to infection with HIV. Therefore, they represent a significant weapon against infection if they can be directed and armed to destroy HIV and infected cells.
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44
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“Unconventional” neutralizing activity of antibodies against HIV. Virol Sin 2008. [DOI: 10.1007/s12250-007-0047-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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45
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Chomont N, Hocini H, Gody JC, Bouhlal H, Becquart P, Krief-Bouillet C, Kazatchkine M, Bélec L. Neutralizing monoclonal antibodies to human immunodeficiency virus type 1 do not inhibit viral transcytosis through mucosal epithelial cells. Virology 2008; 370:246-54. [DOI: 10.1016/j.virol.2007.09.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 05/10/2007] [Accepted: 09/06/2007] [Indexed: 11/29/2022]
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46
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Miranda LR, Duval M, Doherty H, Seaman MS, Posner MR, Cavacini LA. The neutralization properties of a HIV-specific antibody are markedly altered by glycosylation events outside the antigen-binding domain. THE JOURNAL OF IMMUNOLOGY 2007; 178:7132-8. [PMID: 17513762 DOI: 10.4049/jimmunol.178.11.7132] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neutralizing Abs constitute a pivotal mechanism of the adaptive immune response against HIV-1 infection. Yet, most of the Abs that appear in the circulation during HIV infection are nonneutralizing. In this study, we report a dramatic change of the neutralizing properties of a human Ab reactive with the nonneutralizing epitope termed cluster I on the HIV-1 transmembrane protein gp41 when the Ab was produced in Chinese hamster ovary (CHO)-K1 cells. Our laboratory has previously reported that the Ab F240, when produced in a hybridoma, is nonneutralizing as assessed by standard neutralization assays. The F240 IgG1 Ab expressed in CHO cells acquired a strong neutralization activity against a broad range of HIV isolates without a change in immunoreactivity. Sequencing of the F240 mRNAs produced in the parental hybridoma and CHO cells revealed identical sequences, suggesting that acquired neutralization resulted from cell-specific posttranslational modifications. We found that the Ab produced by CHO cells is glycosylated to a greater extent than the parental Ab produced by the hybridoma. Moreover, treatment with peptide N-glycosidase F abrogated F240 neutralization, in an isolate-specific manner, but not Ab b12 neutralization. Interestingly, the F240 isotype-switched variants IgG3 and IgG4, also expressed in CHO cells, exhibited identical immunoreactivity to IgG1 isotypes but had clear differences in viral neutralization. These results suggest that structural features of the Ig molecule other than the primary sequence of the variable regions play a more prominent role in HIV neutralization than anticipated.
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Affiliation(s)
- Luis R Miranda
- Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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47
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Duong YT, Meadows DC, Srivastava IK, Gervay-Hague J, North TW. Direct inactivation of human immunodeficiency virus type 1 by a novel small-molecule entry inhibitor, DCM205. Antimicrob Agents Chemother 2007; 51:1780-6. [PMID: 17307982 PMCID: PMC1855571 DOI: 10.1128/aac.01001-06] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
With more than 40 million people living with human immunodeficiency virus (HIV), there is an urgent need to develop drugs that can be used in the form of a topical microbicide to prevent infection through sexual transmission. DCM205 is a recently discovered small-molecule inhibitor of HIV type 1 (HIV-1) that is able to directly inactivate HIV-1 in the absence of a cellular target. DCM205 is active against CXCR4-, CCR5-, and dual-tropic laboratory-adapted and primary strains of HIV-1. DCM205 binds to the HIV-1 envelope glycoprotein, and competition studies map the DCM205 binding at or near the V3 loop of gp120. Binding to this site interferes with the soluble CD4 interaction. With its ability to disable the virus particle, DCM205 represents a promising new class of HIV entry inhibitor that can be used as a strategy in the prevention of HIV-1/AIDS.
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Affiliation(s)
- Yen T Duong
- Center for Comparative Medicine, University of California, Davis, Davis, CA 95616, USA
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48
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Margolin DH, Saunders EH, Bronfin B, de Rosa N, Axthelm MK, Goloubeva OG, Eapen S, Gelman RS, Letvin NL. Germinal center function in the spleen during simian HIV infection in rhesus monkeys. THE JOURNAL OF IMMUNOLOGY 2006; 177:1108-19. [PMID: 16818768 DOI: 10.4049/jimmunol.177.2.1108] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infection with HIV-1, SIV, or simian HIV is associated with abnormalities in the number, size, and structure of germinal centers (GCs). To determine whether these histopathologic abnormalities are associated with abnormalities in Ab development, we analyzed nucleotide sequences of Igs from splenic GCs of simian HIV-infected macaques. Virus-specific GCs were identified in frozen splenic tissue sections by inverse immunohistochemistry using rHIV-1 gp120 as a probe. B cells from envelope-specific GCs were isolated from these sections using laser capture microdissection. Their Igs were amplified from cDNA using nested PCR, then cloned and sequenced. Nucleotide sequences were recovered from nine multimember clonal lineages. Within each lineage, sequences had similar V-D-J or V-J junctions but differed by somatic mutations distributed throughout the variable domain. The clones were highly mutated, similar to that previously reported for HIV-1-specific human IgG Abs. The average clone had 37 mutations in the V region, for a frequency of 0.11 mutations/base. The mutational pattern was strikingly nonrandom, with somatic mutations occurring preferentially at RGYW/WRCY hotspots. Transition mutations were favored over transversions, with C-->T and G-->A replacements together accounting for almost one-third of all mutations. Analysis of replacement and silent mutations in the framework and CDRs suggests that the Igs were subjected to affinity selection. These data demonstrate that the process of Ab maturation is not seriously disrupted in GCs during the early stages of immunodeficiency virus infection, and that Env-specific Igs developing in GCs are subject to extensive somatic mutation and profound selection pressures.
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Affiliation(s)
- David H Margolin
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
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49
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Holl V, Peressin M, Decoville T, Schmidt S, Zolla-Pazner S, Aubertin AM, Moog C. Nonneutralizing antibodies are able to inhibit human immunodeficiency virus type 1 replication in macrophages and immature dendritic cells. J Virol 2006; 80:6177-81. [PMID: 16731957 PMCID: PMC1472578 DOI: 10.1128/jvi.02625-05] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Only five monoclonal antibodies (MAbs) neutralizing a broad range of primary isolates (PI) have been identified up to now. We have found that some MAbs with no neutralizing activities according to the "conventional" neutralization assay, involving phytohemagglutinin-stimulated peripheral blood mononuclear cells as targets, efficiently inhibit the replication of human immunodeficiency virus type 1 (HIV-1) PI in macrophages and immature dendritic cells (iDC). The mechanism of inhibition is distinct from the neutralization of infectivity occurring via Fab fragments and involves the interaction of the F portion with the FcgammaRs present on macrophages and iDC. We propose that, if such nonneutralizing inhibitory antibodies limit mucosal HIV transmission, they should be induced by vaccination.
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Affiliation(s)
- Vincent Holl
- EA 3770, ULP, Institut de Virologie, 3 rue Koeberlé, F-67000 Strasbourg, France
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50
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Longo NS, Lipsky PE. Why do B cells mutate their immunoglobulin receptors? Trends Immunol 2006; 27:374-80. [PMID: 16809065 DOI: 10.1016/j.it.2006.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 05/18/2006] [Accepted: 06/14/2006] [Indexed: 01/12/2023]
Abstract
B cells have the unique ability to acquire large numbers of point mutations in the variable segment of rearranged immunoglobulin (Ig) genes during a germinal center reaction. It is broadly accepted that somatic hypermutation (SHM) and affinity maturation are required to generate memory B cells and to produce antibodies capable of accomplishing the host defense functions of the humoral component of the adaptive immune system. However, several studies illustrate that low-avidity interactions between antigen and the B-cell receptor can induce deletion, receptor editing and a T-dependent immune response, suggesting that the high-avidity binding of antigen is not essential. If enhanced antigen binding is not essential for immune responses, what is the purpose of SHM? An alternative benefit of SHM might be to enhance the ability of B cells to track antigens expressed by rapidly mutating microorganisms.
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Affiliation(s)
- Nancy S Longo
- Repertoire Analysis Group, Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases/ NIH, Bethesda, MD 20892-1560, USA
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