101
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Astronomo RD, Santra S, Ballweber-Fleming L, Westerberg KG, Mach L, Hensley-McBain T, Sutherland L, Mildenberg B, Morton G, Yates NL, Mize GJ, Pollara J, Hladik F, Ochsenbauer C, Denny TN, Warrier R, Rerks-Ngarm S, Pitisuttithum P, Nitayapan S, Kaewkungwal J, Ferrari G, Shaw GM, Xia SM, Liao HX, Montefiori DC, Tomaras GD, Haynes BF, McElrath JM. Neutralization Takes Precedence Over IgG or IgA Isotype-related Functions in Mucosal HIV-1 Antibody-mediated Protection. EBioMedicine 2016; 14:97-111. [PMID: 27919754 PMCID: PMC5161443 DOI: 10.1016/j.ebiom.2016.11.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/10/2016] [Accepted: 11/18/2016] [Indexed: 12/28/2022] Open
Abstract
HIV-1 infection occurs primarily through mucosal transmission. Application of biologically relevant mucosal models can advance understanding of the functional properties of antibodies that mediate HIV protection, thereby guiding antibody-based vaccine development. Here, we employed a human ex vivo vaginal HIV-1 infection model and a rhesus macaque in vivo intrarectal SHIV challenge model to probe the protective capacity of monoclonal broadly-neutralizing (bnAb) and non-neutralizing Abs (nnAbs) that were functionally modified by isotype switching. For human vaginal explants, we developed a replication-competent, secreted NanoLuc reporter virus system and showed that CD4 binding site bnAbs b12 IgG1 and CH31 IgG1 and IgA2 isoforms potently blocked HIV-1JR-CSF and HIV-1Bal26 infection. However, IgG1 and IgA nnAbs, either alone or together, did not inhibit infection despite the presence of FcR-expressing effector cells in the tissue. In macaques, the CH31 IgG1 and IgA2 isoforms infused before high-dose SHIV challenge were completely to partially protective, respectively, while nnAbs (CH54 IgG1 and CH38 mIgA2) were non-protective. Importantly, in both mucosal models IgG1 isotype bnAbs were more protective than the IgA2 isotypes, attributable in part to greater neutralization activity of the IgG1 variants. These findings underscore the importance of potent bnAb induction as a primary goal of HIV-1 vaccine development.
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Affiliation(s)
- Rena D Astronomo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Sampa Santra
- Center of Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Lamar Ballweber-Fleming
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Katharine G Westerberg
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Linh Mach
- Center of Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Tiffany Hensley-McBain
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Laura Sutherland
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Benjamin Mildenberg
- Center of Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Georgeanna Morton
- Center of Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Nicole L Yates
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Gregory J Mize
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Justin Pollara
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Florian Hladik
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, USA; Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | | | - Thomas N Denny
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Ranjit Warrier
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Sorachai Nitayapan
- Royal Thai Army Component, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Guido Ferrari
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - George M Shaw
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Shi-Mao Xia
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Hua-Xin Liao
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | | | - Georgia D Tomaras
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke School of Medicine, Durham, NC, USA
| | - Juliana M McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Department of Medicine, University of Washington, Seattle, WA, USA; Department of Laboratory Medicine, University of Washington, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA.
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102
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Ferrari G, Haynes BF, Koenig S, Nordstrom JL, Margolis DM, Tomaras GD. Envelope-specific antibodies and antibody-derived molecules for treating and curing HIV infection. Nat Rev Drug Discov 2016; 15:823-834. [PMID: 27725635 PMCID: PMC5549020 DOI: 10.1038/nrd.2016.173] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
HIV-1 is a retrovirus that integrates into host chromatin and can remain transcriptionally quiescent in a pool of immune cells. This characteristic enables HIV-1 to evade both host immune responses and antiretroviral drugs, leading to persistent infection. Upon reactivation of proviral gene expression, HIV-1 envelope (HIV-1 Env) glycoproteins are expressed on the cell surface, transforming latently infected cells into targets for HIV-1 Env-specific monoclonal antibodies (mAbs), which can engage immune effector cells to kill productively infected CD4+ T cells and thus limit the spread of progeny virus. Recent innovations in antibody engineering have resulted in novel immunotherapeutics such as bispecific dual-affinity re-targeting (DART) molecules and other bi- and trispecific antibody designs that can recognize HIV-1 Env and recruit cytotoxic effector cells to kill CD4+ T cells latently infected with HIV-1. Here, we review these immunotherapies, which are designed with the goal of curing HIV-1 infection.
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Affiliation(s)
- Guido Ferrari
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27710, USA
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
- Department of Medicine, Duke University, Durham, North Carolina 27710, USA
- Department of Immunology, Duke University, Durham, North Carolina 27710, USA
| | | | | | - David M Margolis
- University of North Carolina at Chapel Hill HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Georgia D Tomaras
- Department of Surgery, Duke University, Durham, North Carolina 27710, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina 27710, USA
- Duke Human Vaccine Institute, Duke University, Durham, North Carolina 27710, USA
- Department of Immunology, Duke University, Durham, North Carolina 27710, USA
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103
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Rationally Designed Vaccines Targeting the V2 Region of HIV-1 gp120 Induce a Focused, Cross-Clade-Reactive, Biologically Functional Antibody Response. J Virol 2016; 90:10993-11006. [PMID: 27630234 DOI: 10.1128/jvi.01403-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/04/2016] [Indexed: 01/27/2023] Open
Abstract
Strong antibody (Ab) responses against V1V2 epitopes of the human immunodeficiency virus type 1 (HIV-1) gp120 envelope (Env) correlated with reduced infection rates in studies of HIV, simian-human immunodeficiency virus (SHIV), and simian immunodeficiency virus (SIV). In order to focus the Ab response on V1V2, we used six V1V2 sequences and nine scaffold proteins to construct immunogens which were tested using various immunization regimens for their ability to induce cross-reactive and biologically active V2 Abs in rabbits. A prime/boost immunization strategy was employed using gp120 DNA and various V1V2-scaffold proteins. The rabbit polyclonal Ab responses (i) were successfully focused on the V1V2 region, with weak or only transient responses to other Env epitopes, (ii) displayed broad cross-reactive binding activity with gp120s and the V1V2 regions of diverse strains from clades B, C, and E, (iii) included V2 Abs with specificities similar to those found in HIV-infected individuals, and (iv) remained detectable ≥1 year after the last boosting dose. Importantly, sera from rabbits receiving V1V2-scaffold immunogens displayed Ab-dependent cellular phagocytosis whereas sera from rabbits receiving only gp120 did not. The results represent the first fully successful example of reverse vaccinology in the HIV vaccine field with rationally designed epitope scaffold immunogens inducing Abs that recapitulate the epitope specificity and biologic activity of the human monoclonal Abs from which the immunogens were designed. Moreover, this is the first immunogenicity study using epitope-targeting, rationally designed vaccine constructs that induced an Fc-mediated activity associated with protection from infection with HIV, SIV, and SHIV. IMPORTANCE Novel immunogens were designed to focus the antibody response of rabbits on the V1V2 epitopes of HIV-1 gp120 since such antibodies were associated with reduced infection rates of HIV, SIV, and SHIV. The vaccine-induced antibodies were broadly cross-reactive with the V1V2 regions of HIV subtypes B, C and E and, importantly, facilitated Fc-mediated phagocytosis, an activity not induced upon immunization of rabbits with gp120. This is the first immunogenicity study of vaccine constructs that focuses the antibody response on V1V2 and induces V2-specific antibodies with the ability to mediate phagocytosis, an activity that has been associated with protection from infection with HIV, SIV, and SHIV.
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104
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Naturally Occurring Fc-Dependent Antibody From HIV-Seronegative Individuals Promotes HIV-Induced IFN-α Production. Sci Rep 2016; 6:37493. [PMID: 27881846 PMCID: PMC5121582 DOI: 10.1038/srep37493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 10/31/2016] [Indexed: 02/06/2023] Open
Abstract
A majority of adults without HIV infection and with a low risk of HIV-exposure have plasma IgG antibodies that enhance the rate and magnitude of HIV-induced interferon alpha (IFN-α) production. Fc-dependent IgG-HIV complexes induce IFN-α rapidly and in high titers in response to HIV concentrations that are too low to otherwise stimulate an effective IFN-α response. IFN-α promoting antibody (IPA) counters HIV-specific inhibition of IFN-α production, and compensates for the inherent delay in IFN-α production common to HIV infection and other viruses. Naturally occurring IPA has the potential to initiate a potent IFN-α response early in the course of HIV mucosal invasion in time to terminate infection prior to the creation of a pool of persistently infected cells. The current study adds IPA as a mediator of an Fc-dependent antiviral state capable of preventing HIV infection.
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105
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Sun P, Morrison BJ, Beckett CG, Liang Z, Nagabhushana N, Li A, Porter KR, Williams M. NK cell degranulation as a marker for measuring antibody-dependent cytotoxicity in neutralizing and non-neutralizing human sera from dengue patients. J Immunol Methods 2016; 441:24-30. [PMID: 27856192 DOI: 10.1016/j.jim.2016.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 10/26/2016] [Accepted: 11/12/2016] [Indexed: 11/30/2022]
Abstract
The study assessed antibody-dependent NK cell degranulation, a biomarker relevant to antibody-dependent cell cytotoxicity (ADCC), to analyze dengue immune sera. We first determined binding intensity of patient sera to the surface of DENV-infected cells and examined the types of antigens expressed on infected cells. Antigens from pre-membrane (PreM) and envelope (E), but not from NS proteins were detected on the surface of infected cells. After adding NK cells to infected target cells previously treated with patient sera, rapid NK cell degranulation was observed. Non-neutralizing patient sera generated comparable NK cell degranulation as that of neutralizing sera, suggesting ADCC may be a protective mechanism apart from Ab neutralization. The level of NK cell degranulation varied dramatically among human individuals and was associated with the level of CD16 expression on NK cells, informing on the complexity of ADCC among human population.
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Affiliation(s)
| | | | | | | | | | - An Li
- University of Maryland College Park, United States
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106
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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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107
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The first 24 h: targeting the window of opportunity for antibody-mediated protection against HIV-1 transmission. Curr Opin HIV AIDS 2016; 11:561-568. [PMID: 27559708 DOI: 10.1097/coh.0000000000000319] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE OF REVIEW I will review evidence that antibodies protect against HIV-1 transmission in a short window of opportunity, involving neutralization, Fc-mediated effector function, or both. RECENT FINDINGS The last decade witnessed a dramatic progress in the understanding of antibody-mediated protection against HIV-1, including active and passive immunization studies in nonhuman primates; association between reduced infection risk and the specificities and function of antibodies in the RV144 clinical trial; identification of potent, broadly neutralizing antibodies; high-resolution structural studies of the HIV-1 envelope trimer; and an increasing appreciation that Fc-mediated effector function is critical to protection against transmission for neutralizing and nonneutralizing antibodies. Less information is known about how antibodies protect in situ, except that they must do in the first 24 h after exposure. New evidence suggests that antibodies protect in an acute innate immune environment involving the NXLRX1 inflammasome and transforming growth factor beta (TGF-β) that favors infection and rapid dissemination of CCR6RORγ Th17 cells. SUMMARY These recent findings set the stage for understanding how antibodies can prevent the transmission of HIV-1. In this context, antibodies must prevent infection in an innate immune environment that strongly favors transmission. This information is key for the development of a vaccine against HIV-1.
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108
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Enhanced binding of antibodies generated during chronic HIV infection to mucus component MUC16. Mucosal Immunol 2016; 9:1549-1558. [PMID: 26960182 PMCID: PMC5017893 DOI: 10.1038/mi.2016.8] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 01/09/2016] [Indexed: 02/04/2023]
Abstract
Transmission of HIV across mucosal barriers accounts for the majority of HIV infections worldwide. Thus, efforts aimed at enhancing protective immunity at these sites are a top priority, including increasing virus-specific antibodies (Abs) and antiviral activity at mucosal sites. Mucin proteins, including the largest cell-associated mucin, mucin 16 (MUC16), help form mucus to provide a physical barrier to incoming pathogens. Here, we describe a natural interaction between Abs and MUC16 that is enhanced in specific disease settings such as chronic HIV infection. Binding to MUC16 was independent of IgG subclass, but strongly associated with shorter Ab glycan profiles, with agalactosylated (G0) Abs demonstrating the highest binding to MUC16. Binding of Abs to epithelial cells was diminished following MUC16 knockdown, and the MUC16 N-linked glycans were critical for binding. Further, agalactosylated VRC01 captured HIV more efficiently in MUC16. These data point to a novel opportunity to enrich Abs at mucosal sites by targeting Abs to MUC16 through changes in Fc glycosylation, potentially blocking viral movement and sequestering the virus far from the epithelial border. Thus, next-generation vaccines or monoclonal therapeutics may enhance protective immunity by tuning Ab glycosylation to promote the enrichment of Abs at mucosal barriers.
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109
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Non-neutralizing antibody functions for protection and control HIV in humans and SIV and SHIV in non-human primates. AIDS 2016; 30:2551-2553. [PMID: 27753680 DOI: 10.1097/qad.0000000000001200] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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110
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Richard J, Pacheco B, Gohain N, Veillette M, Ding S, Alsahafi N, Tolbert WD, Prévost J, Chapleau JP, Coutu M, Jia M, Brassard N, Park J, Courter JR, Melillo B, Martin L, Tremblay C, Hahn BH, Kaufmann DE, Wu X, Smith AB, Sodroski J, Pazgier M, Finzi A. Co-receptor Binding Site Antibodies Enable CD4-Mimetics to Expose Conserved Anti-cluster A ADCC Epitopes on HIV-1 Envelope Glycoproteins. EBioMedicine 2016; 12:208-218. [PMID: 27633463 PMCID: PMC5078604 DOI: 10.1016/j.ebiom.2016.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 11/06/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) has evolved a sophisticated strategy to conceal conserved epitopes of its envelope glycoproteins (Env) recognized by antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies. These antibodies, which are present in the sera of most HIV-1-infected individuals, preferentially recognize Env in its CD4-bound conformation. Accordingly, recent studies showed that small CD4-mimetics (CD4mc) able to “push” Env into this conformation sensitize HIV-1-infected cells to ADCC mediated by HIV + sera. Here we test whether CD4mc also expose epitopes recognized by anti-cluster A monoclonal antibodies such as A32, thought to be responsible for the majority of ADCC activity present in HIV + sera and linked to decreased HIV-1 transmission in the RV144 trial. We made the surprising observation that CD4mc are unable to enhance recognition of HIV-1-infected cells by this family of antibodies in the absence of antibodies such as 17b, which binds a highly conserved CD4-induced epitope overlapping the co-receptor binding site (CoRBS). Our results indicate that CD4mc initially open the trimeric Env enough to allow the binding of CoRBS antibodies but not anti-cluster A antibodies. CoRBS antibody binding further opens the trimeric Env, allowing anti-cluster A antibody interaction and sensitization of infected cells to ADCC. Therefore, ADCC responses mediated by cluster A antibodies in HIV-positive sera involve a sequential opening of the Env trimer on the surface of HIV-1-infected cells. The understanding of the conformational changes required to expose these vulnerable Env epitopes might be important in the design of new strategies aimed at fighting HIV-1. CD4-mimetics fail to enhance recognition of infected cells by anti-cluster A antibodies (Abs). Co-receptor binding site Abs in conjunction with CD4-mimetics allow binding of Env by anti-cluster A Abs. Co-receptor binding site Abs help CD4-mimetics sensitize HIV-1-infected cells to ADCC.
HIV-1 developed sophisticated strategies to conceal vulnerable epitopes of its envelope glycoproteins (Env) recognized by antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies. CD4-mimetics (CD4mc) were shown to sensitize HIV-1-infected cells to ADCC induced by HIV + sera. Here we show that this response requires a sequential opening of Env at the surface of HIV-1-infected cells. Co-receptor binding site antibodies, also present in HIV + sera, are required to expose ADCC-mediating epitopes recognized by anti-cluster A antibodies upon CD4mc addition. The understanding of the conformational changes required to expose anti-cluster A epitopes might be important in the design of new strategies aimed at fighting HIV-1.
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Affiliation(s)
- Jonathan Richard
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada.
| | | | - Neelakshi Gohain
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Maxime Veillette
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Shilei Ding
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Nirmin Alsahafi
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - William D Tolbert
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jérémie Prévost
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Jean-Philippe Chapleau
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | | | - Manxue Jia
- Aaron Diamond AIDS Research Center, Affiliate of the Rockefeller University, New York, NY, USA
| | | | - Jongwoo Park
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Joel R Courter
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Bruno Melillo
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Loïc Martin
- CEA, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Cécile Tremblay
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Daniel E Kaufmann
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard, Cambridge, MA 02139-3583, USA; Department of Medicine, Université de Montréal, Montreal, QC H3C 3T5, Canada; Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xueling Wu
- Aaron Diamond AIDS Research Center, Affiliate of the Rockefeller University, New York, NY, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Division of AIDS, Harvard Medical School, Boston, MA 02115, USA; Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
| | - Marzena Pazgier
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, QC H2X 0A9, Canada; Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC H2X 0A9, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada.
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111
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Gordon SN, Liyanage NPM, Doster MN, Vaccari M, Vargas-Inchaustegui DA, Pegu P, Schifanella L, Shen X, Tomaras GD, Rao M, Billings EA, Schwartz J, Prado I, Bobb K, Zhang W, Montefiori DC, Foulds KE, Ferrari G, Robert-Guroff M, Roederer M, Phan TB, Forthal DN, Stablein DM, Phogat S, Venzon DJ, Fouts T, Franchini G. Boosting of ALVAC-SIV Vaccine-Primed Macaques with the CD4-SIVgp120 Fusion Protein Elicits Antibodies to V2 Associated with a Decreased Risk of SIVmac251 Acquisition. THE JOURNAL OF IMMUNOLOGY 2016; 197:2726-37. [PMID: 27591322 DOI: 10.4049/jimmunol.1600674] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/04/2016] [Indexed: 11/19/2022]
Abstract
The recombinant ALVAC vaccine coupled with the monomeric gp120/alum protein have decreased the risk of HIV and SIV acquisition. Ab responses to the V1/V2 regions have correlated with a decreased risk of virus acquisition in both humans and macaques. We hypothesized that the breadth and functional profile of Abs induced by an ALVAC/envelope protein regimen could be improved by substituting the monomeric gp120 boost, with the full-length single-chain (FLSC) protein. FLSC is a CD4-gp120 fusion immunogen that exposes cryptic gp120 epitopes to the immune system. We compared the immunogenicity and relative efficiency of an ALVAC-SIV vaccine boosted either with bivalent FLSC proteins or with monomeric gp120 in alum. FLSC was superior to monomeric gp120 in directing Abs to the C3 α2 helix, the V5 loop, and the V3 region that contains the putative CCR5 binding site. In addition, FLSC boosting elicited significantly higher binding Abs to V2 and increased both the Ab-dependent cellular cytotoxicity activity and the breadth of neutralizing Abs. However, the FLSC vaccine regimen demonstrated only a trend in vaccine efficacy, whereas the monomeric gp120 regimen significantly decreased the risk of SIVmac251 acquisition. In both vaccine regimens, anti-V2 Abs correlated with a decreased risk of virus acquisition but differed with regard to systemic or mucosal origin. In the FLSC regimen, serum Abs to V2 correlated, whereas in the monomeric gp120 regimen, V2 Abs in rectal secretions, the site of viral challenge, were associated with efficacy.
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Affiliation(s)
- Shari N Gordon
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Namal P M Liyanage
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Melvin N Doster
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Monica Vaccari
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Diego A Vargas-Inchaustegui
- Immune Biology of Retroviral Infection Section, Vaccine Branch, National Cancer Institute, Bethesda, MD 20892
| | - Poonam Pegu
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Luca Schifanella
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | | | | | - Mangala Rao
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | - Erik A Billings
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | | | - Ilia Prado
- Profectus BioSciences Inc., Baltimore, MD 21224
| | | | | | | | - Kathryn E Foulds
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | | | - Marjorie Robert-Guroff
- Immune Biology of Retroviral Infection Section, Vaccine Branch, National Cancer Institute, Bethesda, MD 20892
| | - Mario Roederer
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Tran B Phan
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, CA 92868
| | - Donald N Forthal
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, CA 92868
| | | | | | - David J Venzon
- Biostatistics and Data Management Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | | | - Genoveffa Franchini
- Animal Models and Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892;
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112
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Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses. PLoS Pathog 2016; 12:e1005817. [PMID: 27579713 PMCID: PMC5007037 DOI: 10.1371/journal.ppat.1005817] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 07/19/2016] [Indexed: 12/28/2022] Open
Abstract
Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine-induced antibodies and therapeutic antibodies will enable a better understanding of their capacity to prevent and/or control HIV-1 infection in vivo.
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113
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Zhang R, Alam SM, Yu JS, Scearce R, Lockwood B, Hwang KK, Parks R, Permar S, Brandtzaeg P, Haynes BF, Liao HX. Novel Monoclonal Antibodies for Studies of Human and Rhesus Macaque Secretory Component and Human J-Chain. Monoclon Antib Immunodiagn Immunother 2016; 35:217-26. [PMID: 27386924 DOI: 10.1089/mab.2016.0014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Immunoglobulin A (IgA) antibodies exist in monomeric, dimeric, and secretory forms. Dimerization of IgA depends on a 15-kD polypeptide termed "joining (J) chain," which is also part of the binding site for an epithelial glycoprotein called "secretory component (SC)," whether this after apical cleavage on secretory epithelia is ligand bound in secretory IgA (SIgA) or in a free form. Uncleaved membrane SC, also called the "polymeric Ig receptor," is thus crucial for transcytotic export of SIgA to mucosal surfaces, where it interacts with and modulates commensal bacteria and mediates protective immune responses against exogenous pathogens. To evaluate different forms of IgA, we have produced mouse monoclonal antibodies (MAbs) against human J-chain and free SC. We found that J-chain MAb 9A8 and SC MAb 9H7 identified human dimeric IgA and SIgA in enzyme-linked immunoassay and western blot analysis, as well as functioning in immunohistochemistry to identify cytoplasmic IgA of intestinal lamina propria plasmablasts/plasma cells and crypt epithelium of distal human intestine. Finally, we demonstrated that SC MAb 9H7 cross-reacted with rhesus macaque SIgA. These novel reagents should be of use in the study of the biology of various forms of IgA in humans and SIgA in macaques, as well as in monitoring the production and/or isolation of these forms of IgA.
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Affiliation(s)
- Ruijun Zhang
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina
| | - S Munir Alam
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina.,2 Department of Medicine, Duke University School of Medicine , Durham, North Carolina
| | - Jae-Sung Yu
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina
| | - Richard Scearce
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina
| | - Bradley Lockwood
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina
| | - Kwan-Ki Hwang
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina
| | - Robert Parks
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina
| | - Sallie Permar
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina.,3 Department of Pediatrics, Duke University School of Medicine , Durham, North Carolina
| | - Per Brandtzaeg
- 4 Centre for Immune Regulation (CIR), University of Oslo , Oslo, Norway .,5 LIIPAT, Department Pathology, Oslo University Hospital Rikshospitalet , Oslo, Norway
| | - Barton F Haynes
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina.,2 Department of Medicine, Duke University School of Medicine , Durham, North Carolina
| | - Hua-Xin Liao
- 1 Duke Human Vaccine Institute, Duke University School of Medicine , Durham, North Carolina.,2 Department of Medicine, Duke University School of Medicine , Durham, North Carolina
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114
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Li H, Wang S, Kong R, Ding W, Lee FH, Parker Z, Kim E, Learn GH, Hahn P, Policicchio B, Brocca-Cofano E, Deleage C, Hao X, Chuang GY, Gorman J, Gardner M, Lewis MG, Hatziioannou T, Santra S, Apetrei C, Pandrea I, Alam SM, Liao HX, Shen X, Tomaras GD, Farzan M, Chertova E, Keele BF, Estes JD, Lifson JD, Doms RW, Montefiori DC, Haynes BF, Sodroski JG, Kwong PD, Hahn BH, Shaw GM. Envelope residue 375 substitutions in simian-human immunodeficiency viruses enhance CD4 binding and replication in rhesus macaques. Proc Natl Acad Sci U S A 2016; 113:E3413-22. [PMID: 27247400 PMCID: PMC4914158 DOI: 10.1073/pnas.1606636113] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Most simian-human immunodeficiency viruses (SHIVs) bearing envelope (Env) glycoproteins from primary HIV-1 strains fail to infect rhesus macaques (RMs). We hypothesized that inefficient Env binding to rhesus CD4 (rhCD4) limits virus entry and replication and could be enhanced by substituting naturally occurring simian immunodeficiency virus Env residues at position 375, which resides at a critical location in the CD4-binding pocket and is under strong positive evolutionary pressure across the broad spectrum of primate lentiviruses. SHIVs containing primary or transmitted/founder HIV-1 subtype A, B, C, or D Envs with genotypic variants at residue 375 were constructed and analyzed in vitro and in vivo. Bulky hydrophobic or basic amino acids substituted for serine-375 enhanced Env affinity for rhCD4, virus entry into cells bearing rhCD4, and virus replication in primary rhCD4 T cells without appreciably affecting antigenicity or antibody-mediated neutralization sensitivity. Twenty-four RMs inoculated with subtype A, B, C, or D SHIVs all became productively infected with different Env375 variants-S, M, Y, H, W, or F-that were differentially selected in different Env backbones. Notably, SHIVs replicated persistently at titers comparable to HIV-1 in humans and elicited autologous neutralizing antibody responses typical of HIV-1. Seven animals succumbed to AIDS. These findings identify Env-rhCD4 binding as a critical determinant for productive SHIV infection in RMs and validate a novel and generalizable strategy for constructing SHIVs with Env glycoproteins of interest, including those that in humans elicit broadly neutralizing antibodies or bind particular Ig germ-line B-cell receptors.
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Affiliation(s)
- Hui Li
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Shuyi Wang
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Rui Kong
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Wenge Ding
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Fang-Hua Lee
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Zahra Parker
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Eunlim Kim
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Gerald H Learn
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Paul Hahn
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ben Policicchio
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261
| | | | - Claire Deleage
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Xingpei Hao
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Matthew Gardner
- Department of Infectious Disease, Scripps Research Institute, Jupiter, FL 33458
| | | | | | - Sampa Santra
- Center of Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA 02215
| | - Cristian Apetrei
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261
| | - Ivona Pandrea
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261
| | - S Munir Alam
- Department of Medicine, Duke University, Durham, NC 27710
| | - Hua-Xin Liao
- Department of Medicine, Duke University, Durham, NC 27710
| | - Xiaoying Shen
- Department of Medicine, Duke University, Durham, NC 27710
| | | | - Michael Farzan
- Department of Infectious Disease, Scripps Research Institute, Jupiter, FL 33458
| | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Jacob D Estes
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Robert W Doms
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | | | | | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215
| | - Peter D Kwong
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Beatrice H Hahn
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
| | - George M Shaw
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
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115
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Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus. PLoS Pathog 2016; 12:e1005619. [PMID: 27163788 PMCID: PMC4862634 DOI: 10.1371/journal.ppat.1005619] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/18/2016] [Indexed: 01/18/2023] Open
Abstract
Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM) exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX) transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU), we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic “signatures” within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission. While the global spread of HIV-1 has been fueled by sexual transmission the genetic determinants underlying the transmission bottleneck remains poorly understood. Here we characterized founder virus population diversity from next generation sequencing data in a cohort of 74 acute and early HIV-1 infected individuals. We observe that the risk of multi-variant infection in men-who-have-sex-with-men (MSM) is not greater than that observed for heterosexuals (HSX), contrary to reports of higher rates of multiple founder virus infections in higher-risk MSM transmissions. These findings were further supported through a metadata analysis of 354 acute and early HIV-1 subjects. We did, however, observe differences between HSM and MSM founder viruses, including a higher selection barrier in HSX transmission with founder viruses being more cohort consensus-like that may be reflective of increased replicative fitness. We also identified a number of residues within Envelope that behave in a risk-dependent manner and could be key for HIV-1 transmission. These novel insights improve our understanding of the HIV-1 transmission bottleneck and underscore the differential selective pressures that founder viruses within the two major transmission risk groups are subjected to.
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116
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Musich T, Robert-Guroff M. New developments in an old strategy: heterologous vector primes and envelope protein boosts in HIV vaccine design. Expert Rev Vaccines 2016; 15:1015-27. [PMID: 26910195 DOI: 10.1586/14760584.2016.1158108] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Prime/boost vaccination strategies for HIV/SIV vaccine development have been used since the early 1990s and have become an established method for eliciting cell and antibody mediated immunity. Here we focus on induction of protective antibodies, both broadly neutralizing and non-neutralizing, with the viral envelope being the key target antigen. Prime/boost approaches are complicated by the diversity of autologous and heterologous priming vectors, and by various forms of envelope booster immunogens, many still in development as structural studies aim to design stable constructs with exposure of critical epitopes for protective antibody elicitation. This review discusses individual vaccine components, reviews recent prime/boost strategies and their outcomes, and highlights complicating factors arising as greater knowledge concerning induction of adaptive, protective immunity is acquired.
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Affiliation(s)
- Thomas Musich
- a Vaccine Branch, Center for Cancer Research, National Cancer Institute , National Institutes of Health , Bethesda , MD , USA
| | - Marjorie Robert-Guroff
- a Vaccine Branch, Center for Cancer Research, National Cancer Institute , National Institutes of Health , Bethesda , MD , USA
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117
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Wessler T, Chen A, McKinley SA, Cone R, Forest MG, Lai SK. Using Computational Modeling To Optimize the Design of Antibodies That Trap Viruses in Mucus. ACS Infect Dis 2016; 2:82-92. [PMID: 26771004 DOI: 10.1021/acsinfecdis.5b00108] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Immunoglobulin G (IgG) antibodies that trap viruses in cervicovaginal mucus (CVM) via adhesive interactions between IgG-Fc and mucins have recently emerged as a promising strategy to block vaginally transmitted infections. The array of IgG bound to a virus particle appears to trap the virus by making multiple weak affinity bonds to the fibrous mucins that form the mucus gel. However, the antibody characteristics that maximize virus trapping and minimize viral infectivity remain poorly understood. Toward this goal, we developed a mathematical model that takes into account physiologically relevant spatial dimensions and time scales, binding, and unbinding rates between IgG and virions and between IgG and mucins, as well as the respective diffusivities of virions and IgG in semen and CVM. We then systematically explored the IgG-antigen and IgG-mucin binding and unbinding rates that minimize the flux of infectious HIV arriving at the vaginal epithelium. Surprisingly, contrary to common intuition that infectivity would drop monotonically with increasing affinities between IgG and HIV, and between IgG and mucins, our model suggests maximal trapping of HIV and minimal flux of HIV to the epithelium are achieved with IgG molecules that exhibit (i) rapid antigen binding (high kon) rather than very slow unbinding (low koff), that is, high-affinity binding to the virion, and (ii) relatively weak affinity with mucins. These results provide important insights into the design of more potent "mucotrapping" IgG for enhanced protection against vaginally transmitted infections. The model is adaptable to other pathogens, mucosal barriers, geometries, and kinetic and diffusional effects, providing a tool for hypothesis testing and producing quantitative insights into the dynamics of immune-mediated protection.
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Affiliation(s)
- Timothy Wessler
- Departments of Mathematics and Applied Physical Science, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Alex Chen
- Departments of Mathematics and Applied Physical Science, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Scott A. McKinley
- Mathematics Department, Tulane University, New Orleans, Louisiana 70118, United States
| | - Richard Cone
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - M. Gregory Forest
- Departments of Mathematics and Applied Physical Science, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
- UNC/NCSU Joint Department of Biomedical
Engineering, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Samuel K. Lai
- Division of Molecular Pharmaceutics, Eshelman School
of Pharmacy, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
- UNC/NCSU Joint Department of Biomedical
Engineering, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department of Microbiology & Immunology, University of North Carolina—Chapel Hill, Chapel Hill, North Carolina 27599, United States
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118
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Abstract
Recent biological, structural, and technical advances are converging within the HIV-1 vaccine field to harness the power of antibodies for prevention and therapy. Numerous monoclonal antibodies with broad neutralizing activity against diverse HIV-1 isolates have now been identified, revealing at least five sites of vulnerability on the envelope (Env) glycoproteins. While there are practical and technological barriers blocking a clear path from broadly neutralizing antibodies (bNAb) to a protective vaccine, this is not a dead end. Scientists are revisiting old approaches with new technology, cutting new trails through unexplored territory, and paving new roads in the hopes of preventing HIV-1 infection. Other promising avenues to capitalize on the power of bNAbs are also being pursued, such as passive antibody immunotherapy and gene therapy approaches. Moreover, non-neutralizing antibodies have inhibitory activities that could have protective potential, alone or in combination with bNAbs. With a new generation of bNAbs, and a clinical trial that associated antibodies with reduced acquisition, the field is closer than ever to developing strategies to use antibodies against HIV-1.
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Affiliation(s)
- S Abigail Smith
- Yerkes National Primate Research Center, Atlanta, Georgia, 30322, USA
| | - Cynthia A Derdeyn
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, 30322, USA; Yerkes National Primate Research Center, Atlanta, Georgia, 30322, USA
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119
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Conformational Masking and Receptor-Dependent Unmasking of Highly Conserved Env Epitopes Recognized by Non-Neutralizing Antibodies That Mediate Potent ADCC against HIV-1. Viruses 2015; 7:5115-32. [PMID: 26393642 PMCID: PMC4584300 DOI: 10.3390/v7092856] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/12/2015] [Accepted: 08/18/2015] [Indexed: 01/11/2023] Open
Abstract
The mechanism of antibody-mediated protection is a major focus of HIV-1 vaccine development and a significant issue in the control of viremia. Virus neutralization, Fc-mediated effector function, or both, are major mechanisms of antibody-mediated protection against HIV-1, although other mechanisms, such as virus aggregation, are known. The interplay between virus neutralization and Fc-mediated effector function in protection against HIV-1 is complex and only partially understood. Passive immunization studies using potent broadly neutralizing antibodies (bnAbs) show that both neutralization and Fc-mediated effector function provides the widest dynamic range of protection; however, a vaccine to elicit these responses remains elusive. By contrast, active immunization studies in both humans and non-human primates using HIV-1 vaccine candidates suggest that weakly neutralizing or non-neutralizing antibodies can protect by Fc-mediated effector function, albeit with a much lower dynamic range seen for passive immunization with bnAbs. HIV-1 has evolved mechanisms to evade each type of antibody-mediated protection that must be countered by a successful AIDS vaccine. Overcoming the hurdles required to elicit bnAbs has become a major focus of HIV-1 vaccine development. Here, we discuss a less studied problem, the structural basis of protection (and its evasion) by antibodies that protect only by potent Fc-mediated effector function.
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120
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Influences on the Design and Purification of Soluble, Recombinant Native-Like HIV-1 Envelope Glycoprotein Trimers. J Virol 2015; 89:12189-210. [PMID: 26311893 DOI: 10.1128/jvi.01768-15] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 08/20/2015] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED We have investigated factors that influence the production of native-like soluble, recombinant trimers based on the env genes of two isolates of human immunodeficiency virus type 1 (HIV-1), specifically 92UG037.8 (clade A) and CZA97.012 (clade C). When the recombinant trimers based on the env genes of isolates 92UG037.8 and CZA97.012 were made according to the SOSIP.664 design and purified by affinity chromatography using broadly neutralizing antibodies (bNAbs) against quaternary epitopes (PGT145 and PGT151, respectively), the resulting trimers are highly stable and they are fully native-like when visualized by negative-stain electron microscopy. They also have a native-like (i.e., abundant) oligomannose glycan composition and display multiple bNAb epitopes while occluding those for nonneutralizing antibodies. In contrast, uncleaved, histidine-tagged Foldon (Fd) domain-containing gp140 proteins (gp140UNC-Fd-His), based on the same env genes, very rarely form native-like trimers, a finding that is consistent with their antigenic and biophysical properties and glycan composition. The addition of a 20-residue flexible linker (FL20) between the gp120 and gp41 ectodomain (gp41ECTO) subunits to make the uncleaved 92UG037.8 gp140-FL20 construct is not sufficient to create a native-like trimer, but a small percentage of native-like trimers were produced when an I559P substitution in gp41ECTO was also present. The further addition of a disulfide bond (SOS) to link the gp120 and gp41 subunits in the uncleaved gp140-FL20-SOSIP protein increases native-like trimer formation to ∼20 to 30%. Analysis of the disulfide bond content shows that misfolded gp120 subunits are abundant in uncleaved CZA97.012 gp140UNC-Fd-His proteins but very rare in native-like trimer populations. The design and stabilization method and the purification strategy are, therefore, all important influences on the quality of trimeric Env proteins and hence their suitability as vaccine components. IMPORTANCE Soluble, recombinant multimeric proteins based on the HIV-1 env gene are current candidate immunogens for vaccine trials in humans. These proteins are generally designed to mimic the native trimeric envelope glycoprotein (Env) that is the target of virus-neutralizing antibodies on the surfaces of virions. The underlying hypothesis is that an Env-mimetic protein may be able to induce antibodies that can neutralize the virus broadly and potently enough for a vaccine to be protective. Multiple different designs for Env-mimetic trimers have been put forth. Here, we used the CZA97.012 and 92UG037.8 env genes to compare some of these designs and determine which ones best mimic virus-associated Env trimers. We conclude that the most widely used versions of CZA97.012 and 92UG037.8 oligomeric Env proteins do not resemble the trimeric Env glycoprotein on HIV-1 viruses, which has implications for the design and interpretation of ongoing or proposed clinical trials of these proteins.
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