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Adriana Irimia, Andreia M Serra, Anita Sarkar, Ronald Jacak, Oleksandr Kalyuzhniy, Devin Sok, Karen L Saye-Francisco, Torben Schiffner, Ryan Tingle, Michael Kubitz, Yumiko Adachi, Robyn L Stanfield, Marc C Deller, Dennis R Burton, William R Schief, Ian A Wilson
Among broadly neutralizing antibodies to HIV, 10E8 exhibits greater neutralizing breadth than most. Consequently, this antibody is the focus of prophylactic/therapeutic development. The 10E8 epitope has been identified as the conserved membrane proximal external region (MPER) of gp41 subunit of the envelope (Env) viral glycoprotein and is a major vaccine target. However, the MPER is proximal to the viral membrane and may be laterally inserted into the membrane in the Env prefusion form. Nevertheless, 10E8 has not been reported to have significant lipid-binding reactivity...
February 22, 2017: PLoS Pathogens
Nichole Cerutti, Juan Luis Loredo-Varela, Christophe Caillat, Winfried Weissenhorn
PURPOSE OF REVIEW: We summarize the latest research on the progress to understand the neutralizing epitopes present within the membrane proximal external region (MPER) of the HIV-1 fusion protein subunit gp41. RECENT FINDINGS: The HIV-1 fusion protein subunit gp41 contains a highly conserved sequence that is essential for membrane fusion and targeted by broadly neutralizing antibodies such as 2F5, 4E10, Z13e1, and 10E8. These antibodies recognize a linear gp41 epitope with high affinity, but require additional hydrophobic sequences present in their heavy chain CDR3 for neutralization...
February 15, 2017: Current Opinion in HIV and AIDS
Marcelo T Augusto, Axel Hollmann, Fulvia Troise, Ana S Veiga, Antonello Pessi, Nuno C Santos
The HIV broadly neutralizing antibody 2F5 targets the transiently exposed epitope in the membrane proximal external region (MPER) of HIV-1 gp41, by a two-step mechanism involving the viral membrane and this viral glycoprotein. It was recently shown that 2F5 conjugation with a cholesterol moiety outside of the antibody paratope substantially increases its antiviral activity. Additionally, the antiviral activity of D5, a human antibody that binds to the N-terminal heptad repeat (NHR) of gp41 and lacks membrane binding, was boosted by the same cholesterol conjugation...
January 19, 2017: Colloids and Surfaces. B, Biointerfaces
Constantinos Kurt Wibmer, Jason Gorman, Gabriel Ozorowski, Jinal N Bhiman, Daniel J Sheward, Debra H Elliott, Julie Rouelle, Ashley Smira, M Gordon Joyce, Nonkululeko Ndabambi, Aliaksandr Druz, Mangai Asokan, Dennis R Burton, Mark Connors, Salim S Abdool Karim, John R Mascola, James E Robinson, Andrew B Ward, Carolyn Williamson, Peter D Kwong, Lynn Morris, Penny L Moore
A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41...
2017: PLoS Pathogens
Edurne Rujas, Jose M M Caaveiro, Angélica Partida-Hanon, Naveed Gulzar, Koldo Morante, Beatriz Apellániz, Miguel García-Porras, Marta Bruix, Kouhei Tsumoto, Jamie K Scott, M Ángeles Jiménez, José L Nieva
The mechanism by which the HIV-1 MPER epitope is recognized by the potent neutralizing antibody 10E8 at membrane interfaces remains poorly understood. To solve this problem, we have optimized a 10E8 peptide epitope and analyzed the structure and binding activities of the antibody in membrane and membrane-like environments. The X-ray crystal structure of the Fab-peptide complex in detergents revealed for the first time that the epitope of 10E8 comprises a continuous helix spanning the gp41 MPER/transmembrane domain junction (MPER-N-TMD; Env residues 671-687)...
December 1, 2016: Scientific Reports
Todd Bradley, Guang Yang, Olga Ilkayeva, T Matt Holl, Ruijun Zhang, Jinsong Zhang, Sampa Santra, Christopher B Fox, Steve G Reed, Robert Parks, Cindy M Bowman, Hilary Bouton-Verville, Laura L Sutherland, Richard M Scearce, Nathan Vandergrift, Thomas B Kepler, M Anthony Moody, Hua-Xin Liao, S Munir Alam, Roger McLendon, Jeffrey I Everitt, Christopher B Newgard, Laurent Verkoczy, Garnett Kelsoe, Barton F Haynes
The HIV-1 envelope protein (Env) has evolved to subvert the host immune system, hindering viral control by the host. The tryptophan metabolic enzyme kynureninase (KYNU) is mimicked by a portion of the HIV Env gp41 membrane proximal region (MPER) and is cross-reactive with the HIV broadly neutralizing Ab (bnAb) 2F5. Molecular mimicry of host proteins by pathogens can lead to autoimmune disease. In this article, we demonstrate that neither the 2F5 bnAb nor HIV MPER-KYNU cross-reactive Abs elicited by immunization with an MPER peptide-liposome vaccine in 2F5 bnAb VHDJH and VLJL knock-in mice and rhesus macaques modified KYNU activity or disrupted tissue tryptophan metabolism...
December 15, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Hannah M Cheeseman, Natalia J Olejniczak, Paul M Rogers, Abbey B Evans, Deborah F L King, Paul Ziprin, Hua-Xin Liao, Barton F Haynes, Robin J Shattock
: Definition of the key parameters mediating effective antibody blocking of HIV-1 acquisition within mucosal tissue may prove critical to effective vaccine development and the prophylactic use of monoclonal antibodies. Although direct antibody-mediated neutralization is highly effective against cell-free virus, antibodies targeting different sites of envelope vulnerability may display differential activity against mucosal infection. Nonneutralizing antibodies (nnAbs) may also impact mucosal transmission events through Fc-gamma receptor (FcγR)-mediated inhibition...
January 1, 2017: Journal of Virology
Bibek Parajuli, Kriti Acharya, Reina Yu, Brendon Ngo, Adel A Rashad, Cameron F Abrams, Irwin M Chaiken
We recently reported the discovery of a recombinant chimera, denoted DAVEI (dual-acting virucidal entry inhibitor), which is able to selectively cause specific and potent lytic inactivation of both pseudotyped and fully infectious human immunodeficiency virus (HIV-1) virions. The chimera is composed of the lectin cyanovirin-N (CVN) fused to the 20-residue membrane-proximal external region (MPER) of HIV-1 gp41. Because the Env gp120-binding CVN domain on its own is not lytic, we sought here to determine how the MPER(DAVEI) domain is able to endow the chimera with virolytic activity...
November 8, 2016: Biochemistry
Todd Bradley, Ashley Trama, Nancy Tumba, Elin Gray, Xiaozhi Lu, Navid Madani, Fatemeh Jahanbakhsh, Amanda Eaton, Shi-Mao Xia, Robert Parks, Krissey E Lloyd, Laura L Sutherland, Richard M Scearce, Cindy M Bowman, Susan Barnett, Salim S Abdool-Karim, Scott D Boyd, Bruno Melillo, Amos B Smith, Joseph Sodroski, Thomas B Kepler, S Munir Alam, Feng Gao, Mattia Bonsignori, Hua-Xin Liao, M Anthony Moody, David Montefiori, Sampa Santra, Lynn Morris, Barton F Haynes
Most HIV-1 vaccines elicit neutralizing antibodies that are active against highly sensitive (tier-1) viruses or rare cases of vaccine-matched neutralization-resistant (tier-2) viruses, but no vaccine has induced antibodies that can broadly neutralize heterologous tier-2 viruses. In this study, we isolated antibodies from an HIV-1-infected individual that targeted the gp41 membrane-proximal external region (MPER) that may have selected single-residue changes in viral variants in the MPER that resulted in neutralization sensitivity to antibodies targeting distal epitopes on the HIV-1 Env...
October 2016: EBioMedicine
John M Louis, James L Baber, Rodolfo Ghirlando, Annie Aniana, Ad Bax, Julien Roche
The transitioning of the ectodomain of gp41 from a pre-hairpin to a six-helix bundle conformation is a crucial aspect of virus-cell fusion. To gain insight into the intermediary steps of the fusion process we have studied the pH and dodecyl phosphocholine (DPC) micelle dependent trimer association of gp41 by systematic deletion analysis of an optimized construct termed 17-172 (residues 528 to 683 of Env) that spans the fusion peptide proximal region (FPPR) to the membrane proximal external region (MPER) of gp41, by sedimentation velocity and double electron-electron resonance (DEER) EPR spectroscopy...
2016: PloS One
Luke R Donius, Yuxing Cheng, Jaewon Choi, Zhen-Yu J Sun, Melissa Hanson, Michael Zhang, Todd M Gierahn, Susanna Marquez, Mohammed Uduman, Steven H Kleinstein, Darrell Irvine, J Christopher Love, Ellis L Reinherz, Mikyung Kim
UNLABELLED: An effective preventive vaccine is highly sought after in order to stem the current HIV-1 pandemic. Both conservation of contiguous gp41 membrane-proximal external region (MPER) amino acid sequences across HIV-1 clades and the ability of anti-MPER broadly neutralizing antibodies (BNAbs) to block viral hemifusion/fusion establish the MPER as a prime vaccination target. In earlier studies, we described the development of an MPER vaccine formulation that takes advantage of liposomes to array the MPER on a lipid bilayer surface, paralleling its native configuration on the virus membrane while also incorporating molecular adjuvant and CD4 T cell epitope cargo...
October 1, 2016: Journal of Virology
Qing-Hai Li, Gang Jin, Jia-Ye Wang, Hai-Ning Li, Huidi Liu, Xiao-Yun Chang, Fu-Xiang Wang, Shu-Lin Liu
The HIV-1 membrane proximal external region (MPER) that is targeted by several broadly neutralizing antibodies (BNAbs) has been considered a potential immunogen for vaccine development. However, to date the immunogenicity of these BNAb epitopes has not been made sufficiently adequate. In the present work, we used live attenuated Salmonella as a platform to present the HIV-1 MPER 10E8 epitope in the fimbriae. The insertion of the 10E8 epitope into the fimbriae had no significant influence on the expression and the absorption capacity of bacterial fimbriae, nor on the virulence and invasiveness of the attenuated Salmonella...
2016: Scientific Reports
Zhiwu Sun, Yun Zhu, Qian Wang, Ling Ye, Yanyan Dai, Shan Su, Fei Yu, Tianlei Ying, Chinglai Yang, Shibo Jiang, Lu Lu
After three decades of intensive research efforts, an effective vaccine against HIV-1 remains to be developed. Several broadly neutralizing antibodies to HIV-1, such as 10E8, recognize the membrane proximal external region (MPER) of the HIV-1 gp41 protein. Thus, the MPER is considered to be a very important target for vaccine design. However, the MPER segment has very weak immunogenicity and tends to insert its epitope residues into the cell membrane, thereby avoiding antibody binding. To address this complication in vaccine development, we herein designed a peptide, designated 10E8-4P, containing four copies of the 10E8 epitope as an immunogen...
June 22, 2016: Emerging Microbes & Infections
Karl W Boehme, Mine' Ikizler, Jason A Iskarpatyoti, J Denise Wetzel, Jordan Willis, James E Crowe, Celia C LaBranche, David C Montefiori, Gregory J Wilson, Terence S Dermody
The gp41 membrane-proximal external region (MPER) is a target for broadly neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1). However, replication-defective virus vaccines currently under evaluation in clinical trials do not efficiently elicit MPER-specific antibodies. Structural modeling suggests that the MPER forms an α-helical coiled coil that is required for function and immunogenicity. To maintain the native MPER conformation, we used reverse genetics to engineer replication-competent reovirus vectors that displayed MPER sequences in the α-helical coiled-coil tail domain of viral attachment protein σ1...
May 2016: MSphere
Cinque Soto, Gilad Ofek, M Gordon Joyce, Baoshan Zhang, Krisha McKee, Nancy S Longo, Yongping Yang, Jinghe Huang, Robert Parks, Joshua Eudailey, Krissey E Lloyd, S Munir Alam, Barton F Haynes, James C Mullikin, Mark Connors, John R Mascola, Lawrence Shapiro, Peter D Kwong
Antibody 10E8 targets the membrane-proximal external region (MPER) of HIV-1 gp41, neutralizes >97% of HIV-1 isolates, and lacks the auto-reactivity often associated with MPER-directed antibodies. The developmental pathway of 10E8 might therefore serve as a promising template for vaccine design, but samples from time-of-infection-often used to infer the B cell record-are unavailable. In this study, we used crystallography, next-generation sequencing (NGS), and functional assessments to infer the 10E8 developmental pathway from a single time point...
2016: PloS One
M Wang, H Zhang, Q-M Liu, Y Sun, Z Li, W-H Liu, X-H He, J Song, Y-X Wang
The successful foamy viruses (FVs) infection includes at least two essential events, attachment to the cell surface and fusion of the viral envelope with the cell membrane. For the FVs, membrane fusion between virus and cell is mediated by envelope glycoprotein (Env) transmembrane (TM) subunit gp47. Compared with other retroviruses, FV TM subunit shares a similar but not identical structural characteristic. This paper focuses on in sillico analyses of all 15 available FV TM subunits gp47 based on their amino acid sequences...
June 2016: Acta Virologica
Rosario Oliva, Alessandro Emendato, Giuseppe Vitiello, Augusta De Santis, Manuela Grimaldi, Anna Maria D'Ursi, Elena Busi, Pompea Del Vecchio, Luigi Petraccone, Gerardino D'Errico
The effect of the 665-683 fragment of the HIV fusion glycoprotein 41, corresponding to the MPER domain of the protein and named gp41MPER, on the microscopic structure and mesoscopic arrangement of palmitoyl oleoyl phosphatidylcholine (POPC) and POPC/sphingomyelin (SM)/cholesterol (CHOL) lipid bilayers is analyzed. The microscopic structuring of the bilayers has been studied by Electron Spin Resonance (ESR) spectroscopy, using glycerophosphocholines spin-labelled in different positions along the acyl chain. Transitions of the bilayer liquid crystalline state have been also monitored by Differential Scanning Calorimetry (DSC)...
August 2016: Biochimica et Biophysica Acta
Daniel J Salamango, Khalid K Alam, Donald H Burke, Marc C Johnson
UNLABELLED: Enveloped viruses utilize transmembrane surface glycoproteins to gain entry into target cells. Glycoproteins from diverse viral families can be incorporated into nonnative viral particles in a process termed pseudotyping; however, the molecular mechanisms governing acquisition of these glycoproteins are poorly understood. For murine leukemia virus envelope (MLV Env) glycoprotein, incorporation into foreign viral particles has been shown to be an active process, but it does not appear to be caused by direct interactions among viral proteins...
July 15, 2016: Journal of Virology
Young D Kwon, Ivelin S Georgiev, Gilad Ofek, Baoshan Zhang, Mangaiarkarasi Asokan, Robert T Bailer, Amy Bao, William Caruso, Xuejun Chen, Misook Choe, Aliaksandr Druz, Sung-Youl Ko, Mark K Louder, Krisha McKee, Sijy O'Dell, Amarendra Pegu, Rebecca S Rudicell, Wei Shi, Keyun Wang, Yongping Yang, Mandy Alger, Michael F Bender, Kevin Carlton, Jonathan W Cooper, Julie Blinn, Joshua Eudailey, Krissey Lloyd, Robert Parks, S Munir Alam, Barton F Haynes, Neal N Padte, Jian Yu, David D Ho, Jinghe Huang, Mark Connors, Richard M Schwartz, John R Mascola, Peter D Kwong
UNLABELLED: Extraordinary antibodies capable of near pan-neutralization of HIV-1 have been identified. One of the broadest is antibody 10E8, which recognizes the membrane-proximal external region (MPER) of the HIV-1 envelope and neutralizes >95% of circulating HIV-1 strains. If delivered passively, 10E8 might serve to prevent or treat HIV-1 infection. Antibody 10E8, however, is markedly less soluble than other antibodies. Here, we describe the use of both structural biology and somatic variation to develop optimized versions of 10E8 with increased solubility...
July 1, 2016: Journal of Virology
Kshitij Wagh, Tanmoy Bhattacharya, Carolyn Williamson, Alex Robles, Madeleine Bayne, Jetta Garrity, Michael Rist, Cecilia Rademeyer, Hyejin Yoon, Alan Lapedes, Hongmei Gao, Kelli Greene, Mark K Louder, Rui Kong, Salim Abdool Karim, Dennis R Burton, Dan H Barouch, Michel C Nussenzweig, John R Mascola, Lynn Morris, David C Montefiori, Bette Korber, Michael S Seaman
The identification of a new generation of potent broadly neutralizing HIV-1 antibodies (bnAbs) has generated substantial interest in their potential use for the prevention and/or treatment of HIV-1 infection. While combinations of bnAbs targeting distinct epitopes on the viral envelope (Env) will likely be required to overcome the extraordinary diversity of HIV-1, a key outstanding question is which bnAbs, and how many, will be needed to achieve optimal clinical benefit. We assessed the neutralizing activity of 15 bnAbs targeting four distinct epitopes of Env, including the CD4-binding site (CD4bs), the V1/V2-glycan region, the V3-glycan region, and the gp41 membrane proximal external region (MPER), against a panel of 200 acute/early clade C HIV-1 Env pseudoviruses...
March 2016: PLoS Pathogens
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