1
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Lisovsky I, Kant S, Tremblay-McLean A, Isitman G, Kiani Z, Dupuy FP, Gilbert L, Bruneau J, Shoukry NH, Lebouché B, Bernard NF. Differential contribution of education through KIR2DL1, KIR2DL3, and KIR3DL1 to antibody-dependent (AD) NK cell activation and ADCC. J Leukoc Biol 2019; 105:551-563. [PMID: 30698860 PMCID: PMC6916277 DOI: 10.1002/jlb.4a0617-242rrr] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 12/07/2018] [Accepted: 12/09/2018] [Indexed: 11/11/2022] Open
Abstract
The engagement of activating NK receptors (aNKR) stimulates NK cell activity, provided that interactions between inhibitory NK receptors (iNKR) with their HLA ligands do not override them. Abs bound to target cells can also activate NK cells by engaging the CD16 aNKR. NK cell education status is an important factor for Ab‐dependent NK cell activation (ADNKA) of some NK cell subsets. However, whether NK cell education also influences Ab‐dependent cellular cytotoxicity (ADCC) levels is not fully known. ADCC‐GranToxiLux (GTL) assays measured ADCC activity as the frequency of granzyme B positive (%GzB+) target cells. Target cells were anti‐HIV Immunoglobulin G (HIVIG)‐opsonized CEM‐NKr.CCR5 (CEM) cells. Lymphocytes and sorted single positive (SP) NKG2A+, KIR2DL1+, KIR2DL3+, and KIR3DL1+ NK cells, to self‐ and nonself HLA, were used as effectors in ADCC‐GTL assays to examine how education status influenced ADCC activity. ADNKA activity was assessed by stimulating lymphocytes with HIVIG‐opsonized CEMs and measuring the frequency of NK cell populations defined by their expression of iNKRs, along with IFN‐γ, CCL4, and CD107a functions. ADCC: the %GzB+ CEM cells generated by self‐ versus nonself HLA‐specific SPiNKR did not differ. ADNKA: More NK cells educated through KIR2DL1 and KIR3DL1, but not KIR2DL3, responded to ADNKA than their uneducated counterparts. CD16 engagement induced ADCC and ADNKA activity. With the proviso that groups’ sizes were small, our results support the notion that NK cell education does not influence ADCC levels but does contribute to ADNKA activity.
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Affiliation(s)
- Irene Lisovsky
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Sanket Kant
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Alexandra Tremblay-McLean
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Gamze Isitman
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Zahra Kiani
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Franck P Dupuy
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada
| | - Louise Gilbert
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada
| | - Julie Bruneau
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada.,Department of Family and Emergency Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Naglaa H Shoukry
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Bertrand Lebouché
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Department of Family Medicine, McGill University, Montréal, Québec, Canada.,Chronic Viral Illness Service, McGill University Health Centre, Montreal, Quebec, Canada
| | - Nicole F Bernard
- Research Institute of the McGill University Health Center (RI-MUHC), Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada.,Chronic Viral Illness Service, McGill University Health Centre, Montreal, Quebec, Canada.,Division of Clinical Immunology, McGill University Health Centre, Montreal, Quebec, Canada
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2
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Tolbert WD, Gohain N, Alsahafi N, Van V, Orlandi C, Ding S, Martin L, Finzi A, Lewis GK, Ray K, Pazgier M. Targeting the Late Stage of HIV-1 Entry for Antibody-Dependent Cellular Cytotoxicity: Structural Basis for Env Epitopes in the C11 Region. Structure 2017; 25:1719-1731.e4. [PMID: 29056481 PMCID: PMC5677539 DOI: 10.1016/j.str.2017.09.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/28/2017] [Accepted: 09/18/2017] [Indexed: 01/14/2023]
Abstract
Antibodies can have an impact on HIV-1 infection in multiple ways, including antibody-dependent cellular cytotoxicity (ADCC), a correlate of protection observed in the RV144 vaccine trial. One of the most potent ADCC-inducing epitopes on HIV-1 Env is recognized by the C11 antibody. Here, we present the crystal structure, at 2.9 Å resolution, of the C11-like antibody N12-i3, in a quaternary complex with the HIV-1 gp120, a CD4-mimicking peptide M48U1, and an A32-like antibody, N5-i5. Antibody N12-i3 recognizes an epitope centered on the N-terminal "eighth strand" of a critical β sandwich, which our analysis indicates to be emblematic of a late-entry state, after the gp120 detachment. In prior entry states, this sandwich comprises only seven strands, with the eighth strand instead pairing with a portion of the gp120 C terminus. The conformational gymnastics of HIV-1 gp120 thus includes altered β-strand pairing, possibly to reduce immunogenicity, although nevertheless still recognized by the human immune system.
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Affiliation(s)
- William D. Tolbert
- Division of Vaccine Research, Institute of Human Virology, Biology of University of Maryland School of Medicine, Baltimore, USA,Department of Biochemistry and Molecular, Biology of University of Maryland School of Medicine, Baltimore, USA
| | - Neelakshi Gohain
- Division of Vaccine Research, Institute of Human Virology, Biology of University of Maryland School of Medicine, Baltimore, USA,Department of Biochemistry and Molecular, Biology of University of Maryland School of Medicine, Baltimore, USA
| | - Nirmin Alsahafi
- Centre de Recherche du CHUM, Université de Montréal, Montreal, Quebec, Canada,CEA, Joliot, Service d’Ingénierie Moléculaire des Protéines, F-91191 Gif-sur-Yvette, France
| | - Verna Van
- Division of Vaccine Research, Institute of Human Virology, Biology of University of Maryland School of Medicine, Baltimore, USA,Department of Biochemistry and Molecular, Biology of University of Maryland School of Medicine, Baltimore, USA
| | - Chiara Orlandi
- Division of Vaccine Research, Institute of Human Virology, Biology of University of Maryland School of Medicine, Baltimore, USA,Department of Microbiology and Immunology of University of Maryland School of Medicine, Baltimore, USA
| | - 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
| | - Loïc Martin
- CEA, Joliot, Service d’Ingénierie Moléculaire des Protéines, F-91191 Gif-sur-Yvette, France
| | - 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, Institute of Human Virology, Biology of University of Maryland School of Medicine, Baltimore, USA,Department of Microbiology and Immunology of University of Maryland School of Medicine, Baltimore, USA
| | - Krishanu Ray
- Department of Biochemistry and Molecular, Biology of University of Maryland School of Medicine, Baltimore, USA
| | - Marzena Pazgier
- Division of Vaccine Research, Institute of Human Virology, Biology of University of Maryland School of Medicine, Baltimore, USA,Department of Biochemistry and Molecular, Biology of University of Maryland School of Medicine, Baltimore, USA,To whom correspondence should be addressed: , 725 West Lombard Street, Baltimore, MD 21201, USA, Tel: (410) 706-4780, Fax: (410) 706-7583
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3
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Kulkarni A, Kurle S, Shete A, Ghate M, Godbole S, Madhavi V, Kent SJ, Paranjape R, Thakar M. Indian Long-term Non-Progressors Show Broad ADCC Responses with Preferential Recognition of V3 Region of Envelope and a Region from Tat Protein. Front Immunol 2017; 8:5. [PMID: 28154562 PMCID: PMC5243827 DOI: 10.3389/fimmu.2017.00005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 01/03/2017] [Indexed: 11/19/2022] Open
Abstract
HIV-specific antibody-dependent cell cytotoxicity (ADCC) is likely to be important in governing protection from human immunodeficiency virus (HIV) and slowing disease progression. Little is known about the ADCC responses to HIV-1 subtype C. We characterized ADCC responses in HIV-1 subtype C-infected Indian subjects with slow disease progression and identified the dominant antigenic regions recognized by these antibodies. ADCC responses were measured in plasma from 34 long-term non-progressors (LTNPs), who were asymptomatic and maintained CD4 count above 500 cells/mm3 for the last 7 years in the absence of antiretroviral therapy (ART), and 58 ART naïve progressors with CD4 count <500 cells/mm3 against overlapping HIV-1 peptides using a flow cytometry-based antibody-dependent natural killer (NK) cell activation assay. The assay measured CD107a expression on NK cells as a marker of antibody-dependent NK cell activation and IFN-γ secretion by NK cells upon activation. The ADCC epitopes were mapped using the matrix of overlapping peptides. Indian LTNPs showed higher and broader ADCC responses compared to the progressors. The Env-C and Tat-specific ADCC responses were associated with lower plasma viral load, whereas the Env-C responses were also associated with higher CD4 counts. Five of 10 LTNP responders targeted epitopes in the V3 region (amino acids 288–330) of Env-C. Additionally, three Tat regions were targeted by ADCC antibodies from LTNPs. ADCC responses were associated with slow HIV progression in Indian subtype C-infected cohort. The frequently recognized peptides from the V3 loop of Env and the novel epitopes from Tat by the LTNPs warrants further study to understand the role of ADCC responses to these regions in control and prevention of HIV-1 infection.
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Affiliation(s)
- Archana Kulkarni
- Department of Immunology and Serology, National AIDS Research Institute , Pune , India
| | - Swarali Kurle
- Department of Immunology and Serology, National AIDS Research Institute , Pune , India
| | - Ashwini Shete
- Department of Immunology and Serology, National AIDS Research Institute , Pune , India
| | - Manisha Ghate
- Department of Clinical Sciences, National AIDS Research Institute , Pune , India
| | - Sheela Godbole
- Department of Epidemiology and Biostatistics, National AIDS Research Institute , Pune , India
| | - Vijaya Madhavi
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne, VIC , Australia
| | - Stephen J Kent
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne, VIC , Australia
| | - Ramesh Paranjape
- Department of Immunology and Serology, National AIDS Research Institute , Pune , India
| | - Madhuri Thakar
- Department of Immunology and Serology, National AIDS Research Institute , Pune , India
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4
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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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5
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Gohain N, Tolbert WD, Acharya P, Yu L, Liu T, Zhao P, Orlandi C, Visciano ML, Kamin-Lewis R, Sajadi MM, Martin L, Robinson JE, Kwong PD, DeVico AL, Ray K, Lewis GK, Pazgier M. Cocrystal Structures of Antibody N60-i3 and Antibody JR4 in Complex with gp120 Define More Cluster A Epitopes Involved in Effective Antibody-Dependent Effector Function against HIV-1. J Virol 2015; 89:8840-54. [PMID: 26085162 PMCID: PMC4524080 DOI: 10.1128/jvi.01232-15] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/05/2015] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Accumulating evidence indicates a role for Fc receptor (FcR)-mediated effector functions of antibodies, including antibody-dependent cell-mediated cytotoxicity (ADCC), in prevention of human immunodeficiency virus type 1 (HIV-1) acquisition and in postinfection control of viremia. Consequently, an understanding of the molecular basis for Env epitopes that constitute effective ADCC targets is of fundamental interest for humoral anti-HIV-1 immunity and for HIV-1 vaccine design. A substantial portion of FcR effector function of potentially protective anti-HIV-1 antibodies is directed toward nonneutralizing, transitional, CD4-inducible (CD4i) epitopes associated with the gp41-reactive region of gp120 (cluster A epitopes). Our previous studies defined the A32-like epitope within the cluster A region and mapped it to the highly conserved and mobile layers 1 and 2 of the gp120 inner domain within the C1-C2 regions of gp120. Here, we elucidate additional cluster A epitope structures, including an A32-like epitope, recognized by human monoclonal antibody (MAb) N60-i3, and a hybrid A32-C11-like epitope, recognized by rhesus macaque MAb JR4. These studies define for the first time a hybrid A32-C11-like epitope and map it to elements of both the A32-like subregion and the seven-layered β-sheet of the gp41-interactive region of gp120. These studies provide additional evidence that effective antibody-dependent effector function in the cluster A region depends on precise epitope targeting--a combination of epitope footprint and mode of antibody attachment. All together these findings help further an understanding of how cluster A epitopes are targeted by humoral responses. IMPORTANCE HIV/AIDS has claimed the lives of over 30 million people. Although antiretroviral drugs can control viral replication, no vaccine has yet been developed to prevent the spread of the disease. Studies of natural HIV-1 infection, simian immunodeficiency virus (SIV)- or simian-human immunodeficiency virus (SHIV)-infected nonhuman primates (NHPs), and HIV-1-infected humanized mouse models, passive transfer studies in infants born to HIV-infected mothers, and the RV144 clinical trial have linked FcR-mediated effector functions of anti-HIV-1 antibodies with postinfection control of viremia and/or blocking viral acquisition. With this report we provide additional definition of the molecular determinants for Env antigen engagement which lead to effective antibody-dependent effector function directed to the nonneutralizing CD4-dependent epitopes in the gp41-reactive region of gp120. These findings have important implications for the development of an effective HIV-1 vaccine.
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Affiliation(s)
- Neelakshi Gohain
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - William D Tolbert
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Priyamvada Acharya
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Lei Yu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tongyun Liu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Pingsen Zhao
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Chiara Orlandi
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Maria L Visciano
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Roberta Kamin-Lewis
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Mohammad M Sajadi
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA Medical Care Clinical Center, VA Maryland Health Care Center, Baltimore, Maryland, USA
| | - Loïc Martin
- CEA, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France
| | - James E Robinson
- Department of Pediatrics, Tulane University Medical Center, New Orleans, Louisiana, USA
| | - Peter D Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Anthony L DeVico
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Krishanu Ray
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - George K Lewis
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Marzena Pazgier
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Euler Z, Alter G. Exploring the potential of monoclonal antibody therapeutics for HIV-1 eradication. AIDS Res Hum Retroviruses 2015; 31:13-24. [PMID: 25385703 DOI: 10.1089/aid.2014.0235] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The HIV field has seen an increased interest in novel cure strategies. In particular, new latency reversal agents are in development to reverse latency to flush the virus out of its hiding place. Combining these efforts with immunotherapeutic approaches may not only drive the virus out of latency, but allow for the rapid elimination of these infected cells in a "shock and kill" approach. Beyond cell-based approaches, growing interest lies in the potential use of functionally enhanced "killer" monoclonal therapeutics to purge the reservoir. Here we discuss prospects for a monoclonal therapeutic-based "shock and kill" strategy that may lead to the permanent elimination of replication-competent virus, making a functional cure a reality for all patients afflicted with HIV worldwide.
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Affiliation(s)
- Zelda Euler
- Ragon Institute of MGH, MIT, and Harvard University , Cambridge, Massachusetts
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7
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Pollara J, Bonsignori M, Moody MA, Pazgier M, Haynes BF, Ferrari G. Epitope specificity of human immunodeficiency virus-1 antibody dependent cellular cytotoxicity [ADCC] responses. Curr HIV Res 2014; 11:378-87. [PMID: 24191939 PMCID: PMC3878369 DOI: 10.2174/1570162x113116660059] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 09/19/2013] [Accepted: 09/28/2013] [Indexed: 12/02/2022]
Abstract
Antibody dependent cellular cytotoxicity [ADCC] has been suggested to play an important role in control of Human Immunodeficiency Virus-1 [HIV-1] viral load and protection from infection. ADCC antibody responses have been mapped to multiple linear and conformational epitopes within the HIV-1 envelope glycoproteins gp120 and gp41. Many epitopes targeted by antibodies that mediate ADCC overlap with those recognized by antibodies capable of virus neutralization. In addition, recent studies conducted with human monoclonal antibodies derived from HIV-1 infected individuals and HIV-1 vaccine-candidate vaccinees have identified a number of antibodies that lack the ability to capture primary HIV-1 isolates or mediate neutralizing activity, but are able to bind to the surface of infected CD4+ T cells and mediate ADCC. Of note, the conformational changes in the gp120 that may not exclusively relate to binding of the CD4 molecule are important in exposing epitopes recognized by ADCC responses. Here we discuss the HIV-1 envelope epitopes targeted by ADCC antibodies in the context of the potential protective capacities of ADCC.
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Affiliation(s)
- Justin Pollara
- Department of Surgery, Duke University Medical Center, P.O. Box 2926, Durham, NC 27710, USA.
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8
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Diverse specificity and effector function among human antibodies to HIV-1 envelope glycoprotein epitopes exposed by CD4 binding. Proc Natl Acad Sci U S A 2013; 110:E69-78. [PMID: 23237851 PMCID: PMC3538257 DOI: 10.1073/pnas.1217609110] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The HIV-1 envelope glycoprotein (Env) undergoes conformational transitions consequent to CD4 binding and coreceptor engagement during viral entry. The physical steps in this process are becoming defined, but less is known about their significance as targets of antibodies potentially protective against HIV-1 infection. Here we probe the functional significance of transitional epitope exposure by characterizing 41 human mAbs specific for epitopes exposed on trimeric Env after CD4 engagement. These mAbs recognize three epitope clusters: cluster A, the gp120 face occluded by gp41 in trimeric Env; cluster B, a region proximal to the coreceptor-binding site (CoRBS) and involving the V1/V2 domain; and cluster C, the coreceptor-binding site. The mAbs were evaluated functionally by antibody-dependent, cell-mediated cytotoxicity (ADCC) and for neutralization of Tiers 1 and 2 pseudoviruses. All three clusters included mAbs mediating ADCC. However, there was a strong potency bias for cluster A, which harbors at least three potent ADCC epitopes whose cognate mAbs have electropositive paratopes. Cluster A epitopes are functional ADCC targets during viral entry in an assay format using virion-sensitized target cells. In contrast, only cluster C contained epitopes that were recognized by neutralizing mAbs. There was significant diversity in breadth and potency that correlated with epitope fine specificity. In contrast, ADCC potency had no relationship with neutralization potency or breadth for any epitope cluster. Thus, Fc-mediated effector function and neutralization coselect with specificity in anti-Env antibody responses, but the nature of selection is distinct for these two antiviral activities.
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9
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Antibody-Dependent Cellular Cytotoxicity and NK Cell-Driven Immune Escape in HIV Infection: Implications for HIV Vaccine Development. Adv Virol 2012; 2012:637208. [PMID: 22611395 PMCID: PMC3350948 DOI: 10.1155/2012/637208] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/13/2012] [Accepted: 02/13/2012] [Indexed: 02/05/2023] Open
Abstract
The HIV-1 genome is malleable and a difficult target tot vaccinate against. It has long been recognised that cytotoxic T lymphocytes and neutralising antibodies readily select for immune escape HIV variants. It is now also clear that NK cells can also select for immune escape. NK cells force immune escape through both direct Killer-immunoglobulin-like receptor (KIR)-mediated killing as well as through facilitating antibody-dependent cellular cytotoxicity (ADCC). These newer finding suggest NK cells and ADCC responses apply significant pressure to the virus. There is an opportunity to harness these immune responses in the design of more effective HIV vaccines.
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10
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Oballah P, Flach B, Eller LA, Eller MA, Ouma B, de Souza M, Kibuuka HN, Wabwire-Mangen F, Brown BK, Michael NL, Robb ML, Montefiori D, Polonis VR. B cell depletion in HIV-1 subtype A infected Ugandan adults: relationship to CD4 T cell count, viral load and humoral immune responses. PLoS One 2011; 6:e22653. [PMID: 21886768 PMCID: PMC3160298 DOI: 10.1371/journal.pone.0022653] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 06/27/2011] [Indexed: 11/19/2022] Open
Abstract
To better understand the nature of B cell dysfunctions in subjects infected with HIV-1 subtype A, a rural cohort of 50 treatment-naïve Ugandan patients chronically infected with HIV-1 subtype A was studied, and the relationship between B cell depletion and HIV disease was assessed. B cell absolute counts were found to be significantly lower in HIV-1+ patients, when compared to community matched negative controls (p<0.0001). HIV-1-infected patients displayed variable functional and binding antibody titers that showed no correlation with viral load or CD4+ T cell count. However, B cell absolute counts were found to correlate inversely with neutralizing antibody (NAb) titers against subtype A (p = 0.05) and subtype CRF02_AG (p = 0.02) viruses. A positive correlation was observed between subtype A gp120 binding antibody titers and NAb breadth (p = 0.02) and mean titer against the 10 viruses (p = 0.0002). In addition, HIV-1 subtype A sera showed preferential neutralization of the 5 subtype A or CRF02_AG pseudoviruses, as compared with 5 pseudoviruses from subtypes B, C or D (p<0.001). These data demonstrate that in patients with chronic HIV-1 subtype A infection, significant B cell depletion can be observed, the degree of which does not appear to be associated with a decrease in functional antibodies. These findings also highlight the potential importance of subtype in the specificity of cross-clade neutralization in HIV-1 infection.
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Affiliation(s)
- Peter Oballah
- Makerere University Walter Reed Project, Kampala, Uganda
| | - Britta Flach
- Makerere University Walter Reed Project, Kampala, Uganda
- Military HIV Research Program, Rockville, Maryland, United States of America
- The Henry M Jackson Foundation, Rockville, Maryland, United States of America
| | - Leigh A. Eller
- Military HIV Research Program, Rockville, Maryland, United States of America
- The Henry M Jackson Foundation, Rockville, Maryland, United States of America
| | - Michael A. Eller
- Military HIV Research Program, Rockville, Maryland, United States of America
- The Henry M Jackson Foundation, Rockville, Maryland, United States of America
| | - Benson Ouma
- Makerere University Walter Reed Project, Kampala, Uganda
| | - Mark de Souza
- Military HIV Research Program, Rockville, Maryland, United States of America
- The Henry M Jackson Foundation, Rockville, Maryland, United States of America
- Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Fred Wabwire-Mangen
- Makerere University Walter Reed Project, Kampala, Uganda
- Makerere University School of Public Health, Kampala, Uganda
| | - Bruce K. Brown
- Military HIV Research Program, Rockville, Maryland, United States of America
- The Henry M Jackson Foundation, Rockville, Maryland, United States of America
| | - Nelson L. Michael
- Military HIV Research Program, Rockville, Maryland, United States of America
- Walter Reed Army Institute of Research, Rockville, Maryland, United States of America
| | - Merlin L. Robb
- Military HIV Research Program, Rockville, Maryland, United States of America
- The Henry M Jackson Foundation, Rockville, Maryland, United States of America
| | - David Montefiori
- Duke University, Durham, North Carolina, United States of America
| | - Victoria R. Polonis
- Military HIV Research Program, Rockville, Maryland, United States of America
- Walter Reed Army Institute of Research, Rockville, Maryland, United States of America
- * E-mail:
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11
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Abstract
OBJECTIVE Increasing data support a role for antibody-dependent cellular cytotoxicity (ADCC) in controlling HIV-1 infection. We recently isolated a naturally occurring dimeric form of the anti-HIV-1 antibody 2G12 and found it to be significantly more potent than 2G12 monomer in neutralizing primary virus strains. However, given the unusual structure of dimeric 2G12 with two Fc regions, it was not clear whether 2G12 dimer could bind to the CD16 Fc receptor on ADCC effector cells or trigger ADCC. Here we compared the in-vitro ADCC activities of 2G12 monomer and dimer and investigated the effects of including ADCC-enhancing mutations in both forms of 2G12. METHODS An in-vitro ADCC assay using target cells stably expressing gp160 was developed to evaluate the activities of 2G12 monomer and dimer with and without ADCC-enhancing mutations that increase the CD16-binding affinity of the 2G12 Fc region. RESULTS Both 2G12 monomer and 2G12 dimer elicited ADCC, although the dimer showed increased potency [lower half-maximal concentration (EC(50))] in triggering ADCC, thus confirming its ability to bind CD16 and trigger ADCC. The ADCC-enhancing mutations improved the ADCC activity of 2G12 monomer more than 2G12 dimer such that their EC(50) values were nearly equal. However, no increase in nonspecific ADCC activity was observed using 2G12 IgGs with these mutations. CONCLUSION Given the likelihood that ADCC plays a role in protecting against initial infection and/or controlling chronic infection, these data suggest 2G12 dimers and/or addition of ADCC-enhancing mutations could augment the prophylactic and/or therapeutic potential of 2G12.
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Ching N, Nielsen-Saines KA, Deville JG, Wei LS, Garratty E, Bryson YJ. Autologous neutralizing antibody to human immunodeficiency virus-1 and replication-competent virus recovered from CD4+ T-cell reservoirs in pediatric HIV-1-infected patients on HAART. AIDS Res Hum Retroviruses 2010; 26:585-91. [PMID: 20455762 DOI: 10.1089/aid.2008.0274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A patient's ability to produce autologous neutralizing antibody (ANAB) to current and past HIV isolates correlates with reduced disease progression and protects against maternal-fetal transmission. Little is known about the effects of prolonged viral suppression on the ANAB response in pediatric HIV-infected patients receiving HAART because the virus is hard to isolate, except by special methods. We therefore assessed ANAB to pre-HAART PBMC virus isolates and post-HAART replication-competent virus (RCV) isolates recovered from latent CD4(+) T-cell reservoirs in perinatally HIV-infected children by using a PBMC-based assay and 90% neutralization titers. We studied two infants and three children before and after HAART. At the time of RCV isolation (n = 4), plasma HIV RNA was <50 copies/ml. At baseline, four of five children had detectable ANAB titers to concurrent pre-HAART virus isolates. Although ANAB was detected in all subjects at several time points despite prolonged HAART and undetectable viremia, the response was variable. ANAB titers to concurrent post-HAART RCV and earlier pre-HAART plasma were present in 3 children suggesting prior exposure to this virus. Post-HAART RCV isolates had reduced replication kinetics in vitro compared to pre-HAART viruses. The presence of ANAB over time suggests that low levels of viral replication may still be ongoing despite HAART. The observation of baseline ANAB activity with earlier plasma against a later RCV suggests that the "latent" reservoir may be established early in life before HAART.
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Affiliation(s)
- Natascha Ching
- Division of Pediatric Infectious Diseases, Department of Pediatrics, David Geffen School of Medicine at UCLA, Mattel Children's Hospital UCLA, Los Angeles, California
| | - Karin A. Nielsen-Saines
- Division of Pediatric Infectious Diseases, Department of Pediatrics, David Geffen School of Medicine at UCLA, Mattel Children's Hospital UCLA, Los Angeles, California
| | - Jaime G. Deville
- Division of Pediatric Infectious Diseases, Department of Pediatrics, David Geffen School of Medicine at UCLA, Mattel Children's Hospital UCLA, Los Angeles, California
| | - Lian S. Wei
- Division of Pediatric Infectious Diseases, Department of Pediatrics, David Geffen School of Medicine at UCLA, Mattel Children's Hospital UCLA, Los Angeles, California
| | - Eileen Garratty
- Division of Pediatric Infectious Diseases, Department of Pediatrics, David Geffen School of Medicine at UCLA, Mattel Children's Hospital UCLA, Los Angeles, California
| | - Yvonne J. Bryson
- Division of Pediatric Infectious Diseases, Department of Pediatrics, David Geffen School of Medicine at UCLA, Mattel Children's Hospital UCLA, Los Angeles, California
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13
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Abstract
Humoral immunity is considered a key component of effective vaccines against HIV-1. Hence, an enormous effort has been put into investigating the neutralizing antibody response to HIV-1 over the past 20 years which generated key information on epitope specificity, potency, breadth and in vivo activity of the neutralizing antibodies. Less clear is still the role of antibody-mediated effector functions (antibody-dependent cellular cytotoxicity, phagocytosis, complement system) and uncertainty prevails whether Fc-mediated mechanisms are largely beneficial or detrimental for the host. The current knowledge on the manifold functions of the humoral immune response in HIV infection, their underlying mechanisms and potential in vaccine-induced immunity will be discussed in this review.
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Affiliation(s)
- M Huber
- Division of Infectious Diseases, University Hospital Zurich, Zurich, Switzerland
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14
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Abstract
As with most pathogens, HIV-1 induces a polyclonal antibody response to a wide array of epitopes on different viral proteins. Studies of polyclonal sera have helped to identify several epitopes on HIV-1 envelope glycoproteins that induce protective antibodies. Antibodies to several constant regions of the virus envelope induce neutralizing antibodies, but because of the poor immunogenicity of some of these epitopes, the rare structure of neutralizing antibodies to these epitopes, or the preponderance of antibodies to particular epitopes that are non-neutralizing rather than neutralizing, targeting each of these epitopes with vaccine constructs presents difficult challenges. Antibodies to variable regions of gp120, such as V1, V2 and V3, have long been considered irrelevant to vaccine design. However, there are conserved features in the stem of the V1/V2 loop and in the V3 loop that have crucial functions in virus infectivity and explain how antibodies to these regions can be crossreactive. These conserved elements within the variable regions might therefore be relevant targets for vaccines. HIV-1 strains exist that are not neutralized by monoclonal antibodies but are neutralized by pooled sera from HIV-1+ individuals. This indicates that there might be neutralizing epitopes that have not yet been identified. Present vaccine protocols induce antibodies to many epitopes rather than focusing the immune response on epitopes that will induce protective antibodies. Given that several neutralizing epitopes in gp120 and gp41 have been identified, it might be advantageous to direct the antibody response to these protective epitopes. It is highly unlikely that a single construct will protect against all subtypes of HIV-1. Given the continuing evolution of the virus and the spread of subtypes throughout the world, the question is how to choose which strains, and how many, need to be represented in a vaccine to give maximum protection.
During the past 20 years, the pendulum of opinion in the HIV-1 vaccine field has swung between two extremes, initially favouring the induction of antibodies only, and subsequently favouring the induction of cell-mediated immune responses only. At present, the consensus seems to be that induction of both humoral and cellular immunity by an HIV-1 vaccine will be required to achieve maximum protection. One obstacle to the development of an effective HIV-1 vaccine has been the difficulty in inducing broadly reactive, potent antibodies with protective functions. Defining epitopes and designing immunogens that will induce these antibodies is one of the main challenges that now confronts the HIV-1 vaccine field.
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Affiliation(s)
- Susan Zolla-Pazner
- New York Veterans Affairs Medical Center and NYU School of Medicine, New York 10016, USA.
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15
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Trkola A, Purtscher M, Muster T, Ballaun C, Buchacher A, Sullivan N, Srinivasan K, Sodroski J, Moore JP, Katinger H. Human monoclonal antibody 2G12 defines a distinctive neutralization epitope on the gp120 glycoprotein of human immunodeficiency virus type 1. J Virol 1996; 70:1100-8. [PMID: 8551569 PMCID: PMC189917 DOI: 10.1128/jvi.70.2.1100-1108.1996] [Citation(s) in RCA: 916] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have isolated and characterized human monoclonal antibody 2G12 to the gp120 surface glycoprotein of human immunodeficiency virus type 1 (HIV-1). This antibody potently and broadly neutralizes primary and T-cell line-adapted clade B strains of HIV-1 in a peripheral blood mononuclear cell-based assay and inhibits syncytium formation in the AA-2 cell line. Furthermore, 2G12 possesses neutralizing activity against strains from clade A but not from clade E. Complement- and antibody-dependent cellular cytotoxicity-activating functions of 2G12 were also defined. The gp120 epitope recognized by 2G12 was found to be distinctive; binding of 2G12 to LAI recombinant gp120 was abolished by amino acid substitutions removing N-linked carbohydrates in the C2, C3, V4, and C4 regions of gp120. This gp120 mutant recognition pattern has not previously been observed, indicating that the 2G12 epitope is unusual. consistent with this, antibodies able to block 2G12 binding to recombinant gp120 were not detected in significant quantities in 16 HIV-positive human serum samples.
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Affiliation(s)
- A Trkola
- Aaron Diamond AIDS Research Center, New York University School of Medicine, New York 10016, USA
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16
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Koup RA, Safrit JT, Cao Y, Andrews CA, McLeod G, Borkowsky W, Farthing C, Ho DD. Temporal association of cellular immune responses with the initial control of viremia in primary human immunodeficiency virus type 1 syndrome. J Virol 1994; 68:4650-5. [PMID: 8207839 PMCID: PMC236393 DOI: 10.1128/jvi.68.7.4650-4655.1994] [Citation(s) in RCA: 1891] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Virologic and immunologic studies were performed on five patients presenting with primary human immunodeficiency virus type 1 (HIV-1) infection. CD8+ cytotoxic T lymphocyte (CTL) precursors specific for cells expressing antigens of HIV-1 Gag, Pol, and Env were detected at or within 3 weeks of presentation in four of the five patients and were detected in all five patients by 3 to 6 months after presentation. The one patient with an absent initial CTL response had prolonged symptoms, persistent viremia, and low CD4+ T-cell count. Neutralizing antibody activity was absent at the time of presentation in all five patients. These findings suggest that cellular immunity is involved in the initial control of virus replication in primary HIV-1 infection and indicate a role for CTL in protective immunity to HIV-1 in vivo.
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Affiliation(s)
- R A Koup
- Aaron Diamond AIDS Research Center, New York University School of Medicine, New York 10016
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17
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Safrit JT, Andrews CA, Zhu T, Ho DD, Koup RA. Characterization of human immunodeficiency virus type 1-specific cytotoxic T lymphocyte clones isolated during acute seroconversion: recognition of autologous virus sequences within a conserved immunodominant epitope. J Exp Med 1994; 179:463-72. [PMID: 8294860 PMCID: PMC2191356 DOI: 10.1084/jem.179.2.463] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Virus-specific cytotoxic T lymphocytes (CTL) are involved in protective immunity to many virus infections. It has recently been shown that CTL are detectable early during primary infection with the primate lentiviruses, human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus. To better characterize the CTL response during acute HIV-1 infection, HIV-1-specific CTL clones were generated from two patients during symptomatic HIV-1 seroconversion. These CTL clones demonstrated specificity for env of HIV-1 and recognized sequences within gp41. Two human histocompatibility leukocyte antigen (HLA) A31-restricted clones from the same individual were found to have differing virus strain specificities. Both clones recognized the 11-amino acid peptide RLRDLLLIVTR from position 770-780 of gp41. A change from T to V at position 779 in this epitope abrogated lysis by one clone but not the other. A CTL clone from the other patient, restricted by a different class I HLA allele, recognized the nine-amino acid peptide HRLRDLLLI from position 769-777 of gp41. Of note, the peptide RLRDLLLIVTR has been shown by others to be presented to CTL by HLA-A3.1. Autologous virus sequences from seroconversion and up to 15 wk after presentation in these two patients were recognized by the CTL clones isolated during acute infection. None of the CTL clones recognized the MN strain of HIV-1, indicating the problems inherent in relying on a single virus strain in the development of a vaccine. These studies have identified an immunodominant and promiscuous area for the generation of CTL responses within gp41. This recognition of autologous virus sequences by the initial CTL response is consistent with the hypothesis that a single virus strain is transmitted to the seroconverter and that the CTL response is involved in the initial control of that virus. These studies indicate the importance of the CTL response to HIV-1 infection and have implications in the design of vaccines.
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Affiliation(s)
- J T Safrit
- Aaron Diamond AIDS Research Center, New York University School of Medicine, New York 10016
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19
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Eaton AM, Ugen KE, Weiner DB, Wildes T, Levy JA. An anti-gp41 human monoclonal antibody that enhances HIV-1 infection in the absence of complement. AIDS Res Hum Retroviruses 1994; 10:13-8. [PMID: 7514015 DOI: 10.1089/aid.1994.10.13] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
B lymphocytes from tonsillar tissue of an asymptomatic HIV-1-seropositive subject were transformed with Epstein-Barr virus (EBV) and tested for the production of HIV-1-specific antibodies by ELISA, using purified HIV-1SF2.2F11, a monoclonal antibody derived from a transformed line, is of the IgG1 subclass and recognizes an epitope in the conserved region of the envelope transmembrane glycoprotein gp41, which is expressed on the surface of HIV-infected T cells. The antibody does not mediate the lysis of infected T cells in antibody-dependent cellular cytotoxicity (ADCC) assays and does not neutralize the infectivity of HIV-1SF2 or the homologous isolate HIV-1TT2.2F11 appears to be the first anti-gp41 human monoclonal antibody that enhances the infectivity of an HIV-1 strain (i.e., SF128A) in the absence of complement.
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Affiliation(s)
- A M Eaton
- Cancer Research Institute, University of California, School of Medicine, San Francisco 94143
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