1
|
Williams KL, Stumpf M, Naiman NE, Ding S, Garrett M, Gobillot T, Vézina D, Dusenbury K, Ramadoss NS, Basom R, Kim PS, Finzi A, Overbaugh J. Identification of HIV gp41-specific antibodies that mediate killing of infected cells. PLoS Pathog 2019; 15:e1007572. [PMID: 30779811 PMCID: PMC6396944 DOI: 10.1371/journal.ppat.1007572] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 03/01/2019] [Accepted: 01/08/2019] [Indexed: 11/19/2022] Open
Abstract
Antibodies that mediate killing of HIV-infected cells through antibody-dependent cellular cytotoxicity (ADCC) have been implicated in protection from HIV infection and disease progression. Despite these observations, these types of HIV antibodies are understudied compared to neutralizing antibodies. Here we describe four monoclonal antibodies (mAbs) obtained from one individual that target the HIV transmembrane protein, gp41, and mediate ADCC activity. These four mAbs arose from independent B cell lineages suggesting that in this individual, multiple B cell responses were induced by the gp41 antigen. Competition and phage peptide display mapping experiments suggested that two of the mAbs target epitopes in the cysteine loop that are highly conserved and a common target of HIV gp41-specific antibodies. The amino acid sequences that bind these mAbs are overlapping but distinct. The two other mAbs were competed by mAbs that target the C-terminal heptad repeat (CHR) and the fusion peptide proximal region (FPPR) and appear to both target a similar unique conformational epitope. These gp41-specific mAbs mediated killing of infected cells that express high levels of Env due to either pre-treatment with interferon or deletion of vpu to increase levels of BST-2/Tetherin. They also mediate killing of target cells coated with various forms of the gp41 protein, including full-length gp41, gp41 ectodomain or a mimetic of the gp41 stump. Unlike many ADCC mAbs that target HIV gp120, these gp41-mAbs are not dependent on Env structural changes associated with membrane-bound CD4 interaction. Overall, the characterization of these four new mAbs that target gp41 and mediate ADCC provides evidence for diverse gp41 B cell lineages with overlapping but distinct epitopes within an individual. Such antibodies that can target various forms of envelope protein could represent a common response to a relatively conserved HIV epitope for a vaccine.
Collapse
Affiliation(s)
- Katherine L. Williams
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
| | - Megan Stumpf
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
| | - Nicole Elise Naiman
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA United States of America
- Medical Scientist Training Program, University of Washington, Seattle WA, United States of America
| | - Shilei Ding
- Department of Microbiology, Infectious Diseases and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Meghan Garrett
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA United States of America
| | - Theodore Gobillot
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA United States of America
- Medical Scientist Training Program, University of Washington, Seattle WA, United States of America
| | - Dani Vézina
- Department of Microbiology, Infectious Diseases and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Katharine Dusenbury
- Medical Scientist Training Program, University of Washington, Seattle WA, United States of America
- Divisions of Basic Sciences and Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Nitya S. Ramadoss
- Stanford ChEM-H and Department of Biochemistry, Stanford University, Stanford, CA, United States of America
| | - Ryan Basom
- Genomics and Bioinformatics Shared Resource, Fred Hutchinson Cancer Research Center, Seattle, WA, United States of America
| | - Peter S. Kim
- Stanford ChEM-H and Department of Biochemistry, Stanford University, Stanford, CA, United States of America
- Chan Zuckerberg Biohub, San Francisco, CA, United States of America
| | - Andrés Finzi
- Department of Microbiology, Infectious Diseases and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle WA, United States of America
| |
Collapse
|
2
|
Molecular and Physicochemical Factors Governing Solubility of the HIV gp41 Ectodomain. Biophys J 2017; 111:700-709. [PMID: 27558714 DOI: 10.1016/j.bpj.2016.07.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 07/01/2016] [Accepted: 07/20/2016] [Indexed: 11/20/2022] Open
Abstract
The HIV gp41 ectodomain (e-gp41) is an attractive target for the development of vaccines and drugs against HIV because of its crucial role in viral fusion to the host cell. However, because of the high insolubility of e-gp41, most biophysical and structural analyses have relied on the production of truncated versions removing the loop region of gp41 or the utilization of nonphysiological solubilizing conditions. The loop region of gp41 is also known as principal immunodominant domain (PID) because of its high immunogenicity, and it is essential for gp41-mediated HIV fusion. In this study we identify the aggregation-prone regions of the amino acid sequence of the PID and engineer a highly soluble mutant that preserves the trimeric structure of the wild-type e-gp41 under physiological pH. Furthermore, using a reverse mutagenesis approach, we analyze the role of mutated amino acids upon the physicochemical factors that govern solubility of e-gp41. On this basis, we propose a molecular model for e-gp41 self-association, which can guide the production of soluble e-gp41 mutants for future biophysical analyses and biotechnological applications.
Collapse
|
3
|
Novel neutralising antibodies targeting the N-terminal helical region of the transmembrane envelope protein p15E of the porcine endogenous retrovirus (PERV). Immunol Res 2014; 58:9-19. [PMID: 23729215 DOI: 10.1007/s12026-013-8430-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Previously, immunising different species with the transmembrane envelope protein p15E of the porcine endogenous retrovirus (PERV), neutralising antibodies were induced which recognised epitopes in the fusion peptide proximal region (FPPR) and in the membrane-proximal external region (MPER). Only the MPER-specific antibodies were shown to neutralise and these antibodies targeted epitopes in the MPER similarly localised as the epitopes recognised by antibodies broadly neutralising HIV-1 such as 2F5 and 4E10. To study whether neutralising antibodies could be induced immunising with subunits of p15E, recombinant proteins corresponding to the N-terminal, the C-terminal helical region (NHR, CHR) and a p15E with a mutation in the Cys-Cys loop were produced. Whereas none of these antigens induced MPER-specific neutralising antibodies, the animals immunised with the FPPR/NHR subunit and the mutated p15E produced neutralising antibodies binding to the NHR. Therefore, for the first time, antibodies specific for the NHR and neutralising PERV were described.
Collapse
|
4
|
Strasz N, Morozov VA, Kreutzberger J, Keller M, Eschricht M, Denner J. Immunization with hybrid proteins containing the membrane proximal external region of HIV-1. AIDS Res Hum Retroviruses 2014; 30:498-508. [PMID: 24392780 DOI: 10.1089/aid.2013.0191] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The transmembrane envelope (TM) protein gp41 of HIV-1 is an attractive target when designing a vaccine to induce neutralizing antibodies. A few broadly neutralizing antibodies (2F5, 4E10, and 10E8) that target conserved epitopes in the membrane proximal external region (MPER) of gp41 have been isolated from infected individuals. However, attempts to induce such antibodies by immunizations with gp41 and Env derivatives containing the MPER were successful only to some extent. In contrast, immunizations with the ectodomain of the TM protein p15E of different gamma retroviruses resulted in the induction of neutralizing antibodies. These sera recognized epitopes located in the MPER and in the fusion peptide proximal region (FPPR) of p15E. Based on these results, both regions of p15E were substituted with the corresponding sequences derived from gp41 of HIV-1. Thus, four different hybrid antigens were produced. One of the inserted sequences contained the epitopes of 2F5 and 4E10 in the MPER; the other corresponded to the FPPR. Vaccination of rats, guinea pigs, and a goat induced binding antibodies directed against the FPPR of gp41 and the 2F5 epitope (ELDKWA) located in the MPER. Despite the exact recognition of the 2F5 epitope, no or very weak neutralization of HIV-1NL4-3 by the immune sera was demonstrated. Nonetheless, using the strategy of hybrid proteins, antibodies targeting the desired epitope were successfully induced.
Collapse
|
5
|
Mühle M, Hoffmann K, Löchelt M, Denner J. Immunisation with foamy virus Bet fusion proteins as novel strategy for HIV-1 epitope delivery. Immunol Res 2013; 56:61-72. [PMID: 23440699 DOI: 10.1007/s12026-013-8387-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The induction of 2F5- and 4E10-like antibodies broadly neutralising HIV-1 and targeting the membrane external proximal region (MPER) of the transmembrane envelope protein gp41 would be a major advancement for the development of a preventive HIV-1 vaccine, but successful attempts remain rare. Recent studies demonstrated that broadly reactive antibodies develop relatively late during infection and after intensive affinity maturation. Therefore, a prolonged antigen delivery might be beneficial to induce them. Replicating foamy viruses which are characterised by apathogenic but persistent infection could represent suitable carrier viruses for this purpose. In order to develop such a system, we modified the accessory foamy virus Bet protein to contain the MPER of gp41, or the MPER linked to the stabilising fusion peptide proximal region of gp41 and analysed here the antigenic and immunogenic properties of such hybrid proteins. The antigens, expressed and purified to homogeneity, were recognised by the monoclonal antibodies 2F5 and 4E10 with nanomolar affinities and induced high levels of antibodies specific to gp41 after immunisation of rats. The antisera also bound to virus particles attached to infected cells, and peptide-based epitope mapping showed that they recognised the 2F5 epitope. Although no HIV-1 neutralising activity was observed, the presented data demonstrate that using the foamy virus Bet for HIV-1 epitope delivery is successfully applicable. Together with the attractive potential for sustained antigen expression after transfer to replicating virus, these results should therefore provide a first basis for the development of chimeric foamy viruses as novel HIV-1 vaccine vectors.
Collapse
Affiliation(s)
- Michael Mühle
- Center for HIV and Retrovirology, Robert Koch Institute, Berlin, Germany
| | | | | | | |
Collapse
|
6
|
Mühle M, Hoffmann K, Löchelt M, Denner J. Construction and characterisation of replicating foamy viral vectors expressing HIV-1 epitopes recognised by broadly neutralising antibodies. Antiviral Res 2013; 100:314-20. [PMID: 24055836 DOI: 10.1016/j.antiviral.2013.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 08/26/2013] [Accepted: 09/10/2013] [Indexed: 10/26/2022]
Abstract
With the aim to develop a replicating vector system for the delivery of HIV-1 antigens on the basis of an apathogenic foamy virus we recently showed that immunisation with purified recombinant hybrid antigens composed of the feline foamy virus Bet protein and parts of the transmembrane envelope protein of HIV-1 induced antibodies with an epitope specificity identical to that of the broadly neutralising antibody 2F5 (Mühle et al., Immunol Res., 2013, 56:61-72). Here we set out to further improve the HIV-1 inserts consisting of the membrane proximal external region (MPER) and the fusion peptide proximal region (FPPR) by stepwise shortening distinct linker residues between both domains. In a subset of these antigens, enhanced recognition by 2F5 and 4E10 was observed, indicating that a specific positioning of FPPR and MPER domains is critical for improved antibody binding. Introduction of these optimised inserts as well as of the MPER domain alone into the feline foamy virus backbone was compatible with virus replication, giving viral titres similar to wild-type virus after extended passaging. Most importantly, expression of the HIV-1 transgenes in infected feline CRFK cells remained stable in three out of four constructs and was detectable after serial passages for several weeks. These data encourage further testing of these vectors in vivo, which may allow insights into the necessity of affinity maturation for the induction of broadly reactive HIV-1 antibodies.
Collapse
Affiliation(s)
- Michael Mühle
- Robert Koch Institute, Nordufer 20, 13353 Berlin, Germany
| | | | | | | |
Collapse
|
7
|
Generation of HIV-1 potent and broad neutralizing antibodies by immunization with postfusion HR1/HR2 complex. AIDS 2013; 27:717-30. [PMID: 23719346 DOI: 10.1097/qad.0b013e32835cfca5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The envelope glycoproteins are major targets for HIV vaccines. The N-terminal and the C-terminal regions of the gp41 interact to form six helix bundles that are responsible for the fusion between the viral and the target cell membranes. Monoclonal antibodies (Abs) able to disrupt the formation of this complex or to interfere with it could inhibit HIV fusion. Most of the well described gp41-specific broadly neutralizing Abs target conformational epitopes within the membrane proximal region of gp41 (MPER) and recognize linear peptides. METHOD AND RESULTS In this study, a stable human transfected cell line, expressing a well folded heptad repeat regions 1 (HR1)/HR2 postfusion complex was developed. Transfected cells were highly immunogenic in mice and allowed the generation of 40 complex specific B-cell clones. Three of them were able to neutralize efficiently both HIV-1 laboratory adapted virus and primary isolates from different clades. Two neutralizing Abs (Nabs) FC-2 and FC-3 bound to a recombinant folded gp140 and blocked with a high potency HR1/HR2 fusion complex formation in vitro. The conformational epitopes of the three antibodies are different to 2F5, 4E10, D5 or NC-1 and mainly located in the MPER region. Abs were capable of inhibiting syncytium formation by blocking spatial interactions between HR1 and HR2 regions. CONCLUSION These findings suggest that immunogenicity of gp41 is achievable and that the use of a fusion complex expressing human cell line is a highly potent immunogen to generate neutralizing antibodies against gp41 envelope glycoprotein.
Collapse
|
8
|
Waechter A, Eschricht M, Denner J. Neutralization of porcine endogenous retrovirus by antibodies against the membrane-proximal external region of the transmembrane envelope protein. J Gen Virol 2013; 94:643-651. [DOI: 10.1099/vir.0.047399-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Immunization of different species including goats, rats, hamsters and guinea pigs with the recombinant ectodomain of the transmembrane envelope (TM) protein p15E of porcine endogenous retrovirus (PERV) has been shown to result in the production of virus-neutralizing antibodies. The sera recognize two groups of epitopes, one located in the fusion peptide-proximal region (FPPR) and the second in the membrane-proximal external region (MPER) of p15E. Most interestingly, the epitopes in the MPER are similar to epitopes in the TM protein gp41 of human immunodeficiency virus type 1 (HIV-1) recognized by mAbs 2F5 and 4E10, which broadly neutralize HIV-1. To study which epitope and which antibody population are involved in the process of neutralization of PERV, this study generated a new antiserum in a goat using an elongated ectodomain of p15E. The immune serum neutralized PERV at a higher titre and recognized broader epitopes in the FPPR and MPER of p15E. For the first time, antibody subpopulations were isolated from this serum using affinity chromatography with immobilized proteins and peptides corresponding to the FPPR and MPER of p15E. Only the affinity-purified antibodies specifically binding the MPER neutralized PERV, indicating that, as in the case of HIV-1, the MPER is an important target of neutralizing activity.
Collapse
|
9
|
Denner J. Immunising with the transmembrane envelope proteins of different retroviruses including HIV-1: a comparative study. Hum Vaccin Immunother 2012; 9:462-70. [PMID: 23249763 DOI: 10.4161/hv.23221] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The induction of neutralizing antibodies is a promising way to prevent retrovirus infections. Neutralizing antibodies are mainly directed against the envelope proteins, which consist of two molecules, the surface envelope (SU) protein and the transmembrane envelope (TM) protein. Antibodies broadly neutralizing the human immunodeficiencvy virus-1 (HIV-1) and binding to the TM protein gp41 of the virus have been isolated from infected individuals. Their epitopes are located in the membrane proximal external region (MPER). Since there are difficulties to induce such neutralizing antibodies as basis for an effective AIDS vaccine, we performed a comparative analysis immunising with the TM proteins of different viruses from the family Retroviridae. Both subfamilies, the Orthoretrovirinae and the Spumaretrovirinae were included. In this study, the TM proteins of three gammaretroviruses including (1) the porcine endogenous retrovirus (PERV), (2) the Koala retrovirus (KoRV), (3) the feline leukemia virus (FeLV), of two lentiviruses, HIV-1, HIV-2, and of two spumaviruses, the feline foamy virus (FFV) and the primate foamy virus (PFV) were used for immunisation. Whereas in all immunisation studies binding antibodies were induced, neutralizing antibodies were only found in the case of the gammaretroviruses. The induced antibodies were directed against the MPER and the fusion peptide proximal region (FPPR) of their TM proteins; however only the antibodies against the MPER were neutralizing. Most importantly, the epitopes in the MPER were localized in the same position as the epitopes of the antibodies broadly neutralizing HIV-1 in the TM protein gp41 of HIV-1, indicating that the MPER is an effective target for the neutralization of retroviruses.
Collapse
|
10
|
Denner J, Mihica D, Kaulitz D, Schmidt CM. Increased titers of neutralizing antibodies after immunization with both envelope proteins of the porcine endogenous retroviruses (PERVs). Virol J 2012; 9:260. [PMID: 23126255 PMCID: PMC3554530 DOI: 10.1186/1743-422x-9-260] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 10/31/2012] [Indexed: 11/29/2022] Open
Abstract
Despite enormous difficulties to induce antibodies neutralizing HIV-1, especially broadly neutralizing antibodies directed against the conserved membrane proximal external region (MPER) of the transmembrane envelope protein, such antibodies can be easily induced in the case of gammaretroviruses, among them the porcine endogenous retroviruses (PERVs). In addition to neutralizing antibodies directed against the transmembrane envelope protein p15E, neutralizing antibodies were also induced by immunization with the surface envelope protein gp70. PERVs represent a special risk for xenotransplantation using pig tissues or organs since they are integrated in the genome of all pigs and infect human cells and a vaccine may protect from transmission to the recipient. To investigate the effect of simultaneous immunization with both proteins in detail, a study was performed in hamsters. Gp70 and p15E of PERV were produced in E. coli, purified and used for immunization. All animals developed binding antibodies against the antigens used for immunization. Sera from animals immunized with p15E recognized epitopes in the MPER and the fusion peptide proximal region (FPPR) of p15E. One MPER epitope showed a sequence homology to an epitope in the MPER of gp41 of HIV-1 recognized by broadly neutralizing antibodies found in HIV infected individuals. Neutralizing antibodies were detected in all sera. Most importantly, sera from animals immunized with gp70 had a higher neutralizing activity when compared with the sera from animals immunized with p15E and sera from animals immunized with gp70 together with p15E had a higher neutralizing activity compared with sera from animals immunized with each antigen alone. These immunization studies are important for the development of vaccines against other retroviruses including the human immunodeficiency virus HIV-1.
Collapse
Affiliation(s)
- Joachim Denner
- Center of HIV and Retrovirology, Robert Koch Institute, Nordufer 20, 13353, Berlin, Germany.
| | | | | | | |
Collapse
|
11
|
Abstract
Antibody-based therapeutics have been successfully used for the treatment of various diseases and as research tools. Several well characterized, broadly neutralizing monoclonal antibodies (bnmAbs) targeting HIV-1 envelope glycoproteins or related host cell surface proteins show sterilizing protection of animals, but they are not effective when used for therapy of an established infection in humans. Recently, a number of novel bnmAbs, engineered antibody domains (eAds), and multifunctional fusion proteins have been reported which exhibit exceptionally potent and broad neutralizing activity against a wide range of HIV-1 isolates from diverse genetic subtypes. eAds could be more effective in vivo than conventional full-size antibodies generated by the human immune system. Because of their small size (12∼15 kD), they can better access sterically restricted epitopes and penetrate densely packed tissue where HIV-1 replicates than the larger full-size antibodies. HIV-1 possesses a number of mechanisms to escape neutralization by full-size antibodies but could be less likely to develop resistance to eAds. Here, we review the in vitro and in vivo antiviral efficacies of existing HIV-1 bnmAbs, summarize the development of eAds and multispecific fusion proteins as novel types of HIV-1 inhibitors, and discuss possible strategies to generate more potent antibody-based candidate therapeutics against HIV-1, including some that could be used to eradicate the virus.
Collapse
Affiliation(s)
- Rui Gong
- Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702-1201, USA.
| | | | | |
Collapse
|
12
|
Reuven EM, Dadon Y, Viard M, Manukovsky N, Blumenthal R, Shai Y. HIV-1 gp41 transmembrane domain interacts with the fusion peptide: implication in lipid mixing and inhibition of virus-cell fusion. Biochemistry 2012; 51:2867-78. [PMID: 22413880 PMCID: PMC3335273 DOI: 10.1021/bi201721r] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fusion of the human immunodeficiency virus (HIV) with target cells is mediated by the gp41 subunit of the envelope protein. Mutation and deletion studies within the transmembrane domain (TMD) of intact gp41 influenced its fusion activity. In addition, current models suggest that the TMD is in proximity with the fusion peptide (FP) at the late fusion stages, but there are no direct experimental data to support this hypothesis. Here, we investigated the TMD focusing on two regions: the N-terminal containing the GxxxG motif and the C-terminal containing the GLRI motif, which is conserved among the TMDs of HIV and the T-cell receptor. Studies utilizing the ToxR expression system combined with synthetic peptides and their fluorescent analogues derived from TMD revealed that the GxxxG motif is important for TMD self-association, whereas the C-terminal region is for its heteroassociation with FP. Functionally, all three TMD peptides induced lipid mixing that was enhanced significantly upon mixing with FP. Furthermore, the TMD peptides inhibited virus-cell fusion apparently through their interaction with their endogenous counterparts. Notably, the R2E mutant (in the GLRI) was significantly less potent than the two others. Overall, our findings provide experimental evidence that HIV-1 TMD contributes to membrane assembly and function of the HIV-1 envelope. Owing to similarities between functional domains within viruses, these findings suggest that the TMDs and FPs may contribute similarly in other viruses as well.
Collapse
Affiliation(s)
- Eliran Moshe Reuven
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Yakir Dadon
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Mathias Viard
- Basic Research Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702
- Nanobiology Program, Center of Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Nurit Manukovsky
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Robert Blumenthal
- Basic Research Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702
| | - Yechiel Shai
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
| |
Collapse
|
13
|
Behrendt R, Fiebig U, Kurth R, Denner J. Induction of Antibodies Binding to the Membrane Proximal External Region of gp36 of HIV-2. Intervirology 2012; 55:252-6. [DOI: 10.1159/000324483] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 01/03/2011] [Indexed: 11/19/2022] Open
|
14
|
Ashkenazi A, Wexler-Cohen Y, Shai Y. Multifaceted action of Fuzeon as virus–cell membrane fusion inhibitor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2352-8. [DOI: 10.1016/j.bbamem.2011.06.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/24/2011] [Accepted: 06/27/2011] [Indexed: 12/30/2022]
|
15
|
Generation of neutralising antibodies against porcine endogenous retroviruses (PERVs). Virology 2011; 411:78-86. [DOI: 10.1016/j.virol.2010.12.032] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 09/20/2010] [Accepted: 12/17/2010] [Indexed: 11/19/2022]
|
16
|
Langhammer S, Hübner J, Jarrett O, Kurth R, Denner J. Immunization with the transmembrane protein of a retrovirus, feline leukemia virus: absence of antigenemia following challenge. Antiviral Res 2010; 89:119-23. [PMID: 21108970 DOI: 10.1016/j.antiviral.2010.11.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 10/20/2010] [Accepted: 11/11/2010] [Indexed: 11/16/2022]
Abstract
A major challenge in the development of vaccines against retroviruses is the induction of neutralizing antibodies since they prevent infection of the cells where the virus may persist. The transmembrane envelope (TM) protein contains highly conserved domains and seems to be a suitable target. To study whether vaccinating with a TM protein of a retrovirus could protect from infection in vivo, cats were immunized with the TM protein p15E of feline leukemia virus (FeLV) and subsequently challenged. For the first time we show that immunization with a retroviral TM protein prevented antigenemia. The level of neutralizing antibodies after the boost immunization correlated with the outcome of FeLV infection.
Collapse
|
17
|
Kanduc D. The self/nonself issue: A confrontation between proteomes. SELF NONSELF 2010; 1:255-258. [PMID: 21487482 DOI: 10.4161/self.1.3.11897] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 01/29/2010] [Indexed: 01/09/2023]
Abstract
Defining self and nonself is the most compelling challenge in science today, at the basis of the numerous questions that remain unanswered in the immunology-pathology-therapy debate. The generation of the antibody repertoire, the complicated scenario offered by tolerance and autoimmunity, natural auto-antibodies and their relationship to autoimmune diseases, and positive and negative selection are only a few examples of the unresolved immunological questions. In this context, we proposed that sequence similarity to the host proteome modulates antigen peptide recognition and immunogenicity. Using the available proteome assemblies of viruses, bacteria and higher vertebrates, and applying the low-similarity criterion, we are systematically defining the proteomic similarity of B-cell epitopes already validated experimentally. Here, we report further data documenting that a low similarity to the host proteome is the common property that defines the immunological "nonself" nature of antigenic sequences in cancer, autoimmunity, infectious diseases and allergy.
Collapse
Affiliation(s)
- Darja Kanduc
- Department of Biochemistry and Molecular Biology; University of Bari; Bari, Italy
| |
Collapse
|
18
|
A neutralization assay for HIV-2 based on measurement of provirus integration by duplex real-time PCR. J Virol Methods 2009; 159:40-6. [PMID: 19442843 DOI: 10.1016/j.jviromet.2009.02.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 02/15/2009] [Accepted: 02/19/2009] [Indexed: 11/24/2022]
Abstract
Specific, effective and rapid neutralization assays are crucial for the development of an HIV vaccine based on the stimulation of neutralizing antibodies and the development of such an assay for the human immunodeficiency virus-2 (HIV-2) is described. Virus neutralization was measured as the reduction of provirus integration using a duplex real-time PCR with high efficiency (99.4%). This PCR uses primers and a probe specific for the proviral LTR. Amplification and quantitative analysis of the cellular GAPDH gene was carried out in parallel to control for toxic or growth-inhibitory components in the sera. The neutralization assay was used to screen sera from 23 HIV-2 infected patients. 21 sera were able to neutralize HIV-2(60415K), 20 sera neutralized HIV-2(7312A) and 7 sera cross-neutralized HIV-1 IIIB. In contrast, when 14 of these sera were tested in parallel with a conventional neutralization assay based on a p27Gag capture ELISA, only one was found to neutralize HIV-2(60415K) and 11 to neutralize HIV-2(7312A) compared with 12 and 13 sera respectively using the PCR-based assay.
Collapse
|