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Richard J, Prévost J, Bourassa C, Brassard N, Boutin M, Benlarbi M, Goyette G, Medjahed H, Gendron-Lepage G, Gaudette F, Chen HC, Tolbert WD, Smith AB, Pazgier M, Dubé M, Clark A, Mothes W, Kaufmann DE, Finzi A. Temsavir blocks the immunomodulatory activities of HIV-1 soluble gp120. Cell Chem Biol 2023; 30:540-552.e6. [PMID: 36958337 PMCID: PMC10198848 DOI: 10.1016/j.chembiol.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 02/03/2023] [Accepted: 03/02/2023] [Indexed: 03/25/2023]
Abstract
While HIV-1-mediated CD4 downregulation protects infected cells from antibody-dependent cellular cytotoxicity (ADCC), shed gp120 binds to CD4 on uninfected bystander CD4+ T cells, sensitizing them to ADCC mediated by HIV+ plasma. Soluble gp120-CD4 interaction on multiple immune cells also triggers a cytokine burst. The small molecule temsavir acts as an HIV-1 attachment inhibitor by preventing envelope glycoprotein (Env)-CD4 interaction and alters the overall antigenicity of Env by affecting its processing and glycosylation. Here we show that temsavir also blocks the immunomodulatory activities of shed gp120. Temsavir prevents shed gp120 from interacting with uninfected bystander CD4+ cells, protecting them from ADCC responses and preventing a cytokine burst. Mechanistically, this depends on temsavir's capacity to prevent soluble gp120-CD4 interaction, to reduce gp120 shedding, and to alter gp120 antigenicity. This suggests that the clinical benefits provided by temsavir could extend beyond blocking viral entry.
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Affiliation(s)
- Jonathan Richard
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Jérémie Prévost
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | | | | | - Marianne Boutin
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Mehdi Benlarbi
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | | | | | | | - Fleur Gaudette
- Plateforme de Pharmacocinétique, Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada
| | - Hung-Ching Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - William D Tolbert
- Infectious Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4712, 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
| | - Mathieu Dubé
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada
| | - Andrew Clark
- ViiV Healthcare, Global Medical Affairs, Middlesex TW8 9GS, UK
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Daniel E Kaufmann
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada; Département de Médecine, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montréal, QC H2X 0A9, Canada; Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, Montréal, QC H2X 0A9, Canada.
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Gupta M, Canziani G, Ang C, Mohammadi M, Abrams CF, Yang D, Smith AB, Chaiken I. Pharmacophore Variants of the Macrocyclic Peptide Triazole Inactivator of HIV-1 Env. RESEARCH SQUARE 2023:rs.3.rs-2814722. [PMID: 37131733 PMCID: PMC10153383 DOI: 10.21203/rs.3.rs-2814722/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Previously we established a family of macrocyclic peptide triazoles (cPTs) that inactivate the Env protein complex of HIV-1, and identified the pharmacophore that engages Env's receptor binding pocket. Here, we examined the hypothesis that the side chains of both components of the triazole Pro - Trp segment of cPT pharmacophore work in tandem to make intimate contacts with two proximal subsites of the overall CD4 binding site of gp120 to stabilize binding and function. Variations of the triazole Pro R group, which previously had been significantly optimized, led to identification of a variant MG-II-20 that contains a pyrazole substitution. MG-II-20 has improved functional properties over previously examined variants, with Kd for gp120 in the nM range. In contrast, new variants of the Trp indole side chain, with either methyl- or bromo- components appended, had disruptive effects on gp120 binding, reflecting the sensitivity of function to changes in this component of the encounter complex. Plausible in silico models of cPT:gp120 complex structures were obtained that are consistent with the overall hypothesisof occupancy by the triazole Pro and Trp side chains, respectively, into the β20/21 and Phe43 sub-cavities. The overall results strengthen the definition of the cPT-Env inactivator binding site and provide a new lead composition (MG-II-20) as well as structure-function findings to guide future HIV-1 Env inactivator design.
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Affiliation(s)
- Monisha Gupta
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
- Department of Chemistry, College of Arts and Sciences, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Gabriela Canziani
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Charles Ang
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Mohammadjavad Mohammadi
- Department of Chemical & Biological Engineering, College of Engineering, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Cameron F Abrams
- Department of Chemical & Biological Engineering, College of Engineering, Drexel University, Philadelphia, Pennsylvania 19102, United States
| | - Derek Yang
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Irwin Chaiken
- Department of Biochemistry and Molecular Biology, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19102, United States
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Abstract
The HIV Env glycoprotein is the surface glycoprotein responsible for viral entry into CD4+ immune cells. During infection, Env also serves as a primary target for antibody responses, which are robust but unable to control virus replication. Immune evasion by HIV-1 Env appears to employ complex mechanisms to regulate what antigenic states are presented to the immune system. Immunodominant features appear to be distinct from epitopes that interfere with Env functions in mediating infection. Further, cell-cell transmission studies indicate that vulnerable conformational states are additionally hidden from recognition on infected cells, even though the presence of Env at the cell surface is required for viral infection through the virological synapse. Cell-cell infection studies support that Env on infected cells is presented in distinct conformations from that on virus particles. Here we review data regarding the regulation of conformational states of Env and assess how regulated sorting of Env within the infected cell may underlie mechanisms to distinguish Env on the surface of virus particles versus Env on the surface of infected cells. These mechanisms may allow infected cells to avoid opsonization, providing cell-to-cell infection by HIV with a selective advantage during evolution within an infected individual. Understanding how distinct Env conformations are presented on cells versus viruses may be essential to designing effective vaccine approaches and therapeutic strategies to clear infected cell reservoirs.
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Affiliation(s)
- Connie Zhao
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hongru Li
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Talia H. Swartz
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin K. Chen
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Prévost J, Medjahed H, Vézina D, Chen HC, Hahn BH, Smith AB, Finzi A. HIV-1 Envelope Glycoproteins Proteolytic Cleavage Protects Infected Cells from ADCC Mediated by Plasma from Infected Individuals. Viruses 2021; 13:2236. [PMID: 34835042 PMCID: PMC8625184 DOI: 10.3390/v13112236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 12/28/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) is synthesized in the endoplasmic reticulum as a trimeric gp160 precursor, which requires proteolytic cleavage by a cellular furin protease to mediate virus-cell fusion. Env is conformationally flexible but controls its transition from the unbound "closed" conformation (State 1) to downstream CD4-bound conformations (States 2/3), which are required for fusion. In particular, HIV-1 has evolved several mechanisms that reduce the premature "opening" of Env which exposes highly conserved epitopes recognized by non-neutralizing antibodies (nnAbs) capable of mediating antibody-dependent cellular cytotoxicity (ADCC). Env cleavage decreases its conformational transitions favoring the adoption of the "closed" conformation. Here we altered the gp160 furin cleavage site to impair Env cleavage and to examine its impact on ADCC responses mediated by plasma from HIV-1-infected individuals. We found that infected primary CD4+ T cells expressing uncleaved, but not wildtype, Env are efficiently recognized by nnAbs and become highly susceptible to ADCC responses mediated by plasma from HIV-1-infected individuals. Thus, HIV-1 limits the exposure of uncleaved Env at the surface of HIV-1-infected cells at least in part to escape ADCC responses.
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Affiliation(s)
- Jérémie Prévost
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Halima Medjahed
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
| | - Dani Vézina
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
| | - Hung-Ching Chen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (H.-C.C.); (A.B.S.III)
| | - 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, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (H.-C.C.); (A.B.S.III)
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC H2X 0A9, Canada; (J.P.); (H.M.); (D.V.)
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H2X 0A9, Canada
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Across Functional Boundaries: Making Nonneutralizing Antibodies To Neutralize HIV-1 and Mediate Fc-Mediated Effector Killing of Infected Cells. mBio 2021; 12:e0140521. [PMID: 34579568 PMCID: PMC8546553 DOI: 10.1128/mbio.01405-21] [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] [Indexed: 12/30/2022] Open
Abstract
In HIV-1 infection, many antibodies (Abs) are elicited to Envelope (Env) epitopes that are conformationally masked in the native trimer and are only available for antibody recognition after the trimer binds host cell CD4. Among these are epitopes within the Co-Receptor Binding Site (CoRBS) and the constant region 1 and 2 (C1-C2 or cluster A region). In particular, C1-C2 epitopes map to the gp120 face interacting with gp41 in the native, "closed" Env trimer present on HIV-1 virions or expressed on HIV-1-infected cells. Antibodies targeting this region are therefore nonneutralizing and their potential as mediators of antibody-dependent cellular cytotoxicity (ADCC) of HIV-1-infected cells diminished by a lack of available binding targets. Here, we present the design of Ab-CD4 chimeric proteins that consist of the Ab-IgG1 of a CoRBS or cluster A specificity to the extracellular domains 1 and 2 of human CD4. Our Ab-CD4 hybrids induce potent ADCC against infected primary CD4+ T cells and neutralize tier 1 and 2 HIV-1 viruses. Furthermore, competition binding experiments reveal that the observed biological activities rely on both the antibody and CD4 moieties, confirming their cooperativity in triggering conformational rearrangements of Env. Our data indicate the utility of these Ab-CD4 hybrids as antibody therapeutics that are effective in eliminating HIV-1 through the combined mechanisms of neutralization and ADCC. This is also the first report of single-chain-Ab-based molecules capable of opening "closed" Env trimers on HIV-1 particles/infected cells to expose the cluster A region and activate ADCC and neutralization against these nonneutralizing targets. IMPORTANCE Highly conserved epitopes within the coreceptor binding site (CoRBS) and constant region 1 and 2 (C1-C2 or cluster A) are only available for antibody recognition after the HIV-1 Env trimer binds host cell CD4; therefore, they are not accessible on virions and infected cells, where the expression of CD4 is downregulated. Here, we have developed new antibody fusion molecules in which domains 1 and 2 of soluble human CD4 are linked with monoclonal antibodies of either the CoRBS or cluster A specificity. We optimized the conjugation sites and linker lengths to allow each of these novel bispecific fusion molecules to recognize native "closed" Env trimers and induce the structural rearrangements required for exposure of the epitopes for antibody binding. Our in vitro functional testing shows that our Ab-CD4 molecules can efficiently target and eliminate HIV-1-infected cells through antibody-dependent cellular cytotoxicity and inactivate HIV-1 virus through neutralization.
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