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Shrestha J, Santerre M, Allen CNS, Arjona SP, Merali C, Mukerjee R, Chitrala KN, Park J, Bagashev A, Bui V, Eugenin EA, Merali S, Kaul M, Chin J, Sawaya BE. HIV-1 gp120 Impairs Spatial Memory Through Cyclic AMP Response Element-Binding Protein. Front Aging Neurosci 2022; 14:811481. [PMID: 35615594 PMCID: PMC9124804 DOI: 10.3389/fnagi.2022.811481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
HIV-associated neurocognitive disorders (HAND) remain an unsolved problem that persists despite using antiretroviral therapy. We have obtained data showing that HIV-gp120 protein contributes to neurodegeneration through metabolic reprogramming. This led to decreased ATP levels, lower mitochondrial DNA copy numbers, and loss of mitochondria cristae, all-important for mitochondrial biogenesis. gp120 protein also disrupted mitochondrial movement and synaptic plasticity. Searching for the mechanisms involved, we found that gp120 alters the cyclic AMP response element-binding protein (CREB) phosphorylation on serine residue 133 necessary for its function as a transcription factor. Since CREB regulates the promoters of PGC1α and BDNF genes, we found that CREB dephosphorylation causes PGC1α and BDNF loss of functions. The data was validated in vitro and in vivo. The negative effect of gp120 was alleviated in cells and animals in the presence of rolipram, an inhibitor of phosphodiesterase protein 4 (PDE4), restoring CREB phosphorylation. We concluded that HIV-gp120 protein contributes to HAND via inhibition of CREB protein function.
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Affiliation(s)
- Jenny Shrestha
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
| | - Maryline Santerre
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
| | - Charles N. S. Allen
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
| | - Sterling P. Arjona
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
| | - Carmen Merali
- Department of Pharmaceutical Sciences, School of Pharmacy, Temple University, Philadelphia, PA, United States
| | - Ruma Mukerjee
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
| | | | - Jin Park
- Memory and Brain Research Center, Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Asen Bagashev
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
| | - Viet Bui
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
| | - Eliseo A. Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, The University of Texas Medical Branch, Galveston, TX, United States
| | - Salim Merali
- Department of Pharmaceutical Sciences, School of Pharmacy, Temple University, Philadelphia, PA, United States
| | - Marcus Kaul
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
- Department of Psychiatry, University of California, San Diego, San Diego, CA, United States
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Jeannie Chin
- Memory and Brain Research Center, Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Bassel E. Sawaya
- Molecular Studies of Neurodegenerative Diseases Lab, Philadelphia, PA, United States
- Fels Cancer Institute for Personalized Medicine Institute, Philadelphia, PA, United States
- Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- Department of Cancer and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- *Correspondence: Bassel E. Sawaya,
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2
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Costantini LM, Irvin SC, Kennedy SC, Guo F, Goldstein H, Herold BC, Snapp EL. Engineering and exploitation of a fluorescent HIV-1 gp120 for live cell CD4 binding assays. Virology 2014; 476:240-248. [PMID: 25555152 DOI: 10.1016/j.virol.2014.12.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/08/2014] [Accepted: 12/09/2014] [Indexed: 10/24/2022]
Abstract
The HIV-1 envelope glycoprotein, gp120, binds the host cell receptor, CD4, in the initial step of HIV viral entry and infection. This process is an appealing target for the development of inhibitory drugs and neutralizing antibodies. To study gp120 binding and intracellular trafficking, we engineered a fluorescent fusion of the humanized gp120 JRFL HIV-1 variant and GFP. Gp120-sfGFP is glycosylated with human sugars, robustly expressed, and secreted from cultured human cells. Protein dynamics, quality control, and trafficking can be visualized in live cells. The fusion protein can be readily modified with different gp120 variants or fluorescent proteins. Finally, secreted gp120-sfGFP enables a sensitive and easy binding assay that can quantitatively screen potential inhibitors of gp120-CD4 binding on live cells via fluorescence imaging or laser scanning cytometry. This adaptable research tool should aid in studies of gp120 cell biology and the development of novel anti-HIV drugs.
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Affiliation(s)
- Lindsey M Costantini
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Susan C Irvin
- Department of Pediatrics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Steven C Kennedy
- Department of Pediatrics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Feng Guo
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Harris Goldstein
- Department of Pediatrics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Betsy C Herold
- Department of Pediatrics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Erik L Snapp
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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3
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Fouda GG, Mahlokozera T, Salazar-Gonzalez JF, Salazar MG, Learn G, Kumar SB, Dennison SM, Russell E, Rizzolo K, Jaeger F, Cai F, Vandergrift NA, Gao F, Hahn B, Shaw GM, Ochsenbauer C, Swanstrom R, Meshnick S, Mwapasa V, Kalilani L, Fiscus S, Montefiori D, Haynes B, Kwiek J, Alam SM, Permar SR. Postnatally-transmitted HIV-1 Envelope variants have similar neutralization-sensitivity and function to that of nontransmitted breast milk variants. Retrovirology 2013; 10:3. [PMID: 23305422 PMCID: PMC3564832 DOI: 10.1186/1742-4690-10-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 12/21/2012] [Indexed: 11/11/2022] Open
Abstract
Background Breastfeeding is a leading cause of infant HIV-1 infection in the developing world, yet only a minority of infants exposed to HIV-1 via breastfeeding become infected. As a genetic bottleneck severely restricts the number of postnatally-transmitted variants, genetic or phenotypic properties of the virus Envelope (Env) could be important for the establishment of infant infection. We examined the efficiency of virologic functions required for initiation of infection in the gastrointestinal tract and the neutralization sensitivity of HIV-1 Env variants isolated from milk of three postnatally-transmitting mothers (n=13 viruses), five clinically-matched nontransmitting mothers (n=16 viruses), and seven postnatally-infected infants (n = 7 postnatally-transmitted/founder (T/F) viruses). Results There was no difference in the efficiency of epithelial cell interactions between Env virus variants from the breast milk of transmitting and nontransmitting mothers. Moreover, there was similar efficiency of DC-mediated trans-infection, CCR5-usage, target cell fusion, and infectivity between HIV-1 Env-pseudoviruses from nontransmitting mothers and postnatal T/F viruses. Milk Env-pseudoviruses were generally sensitive to neutralization by autologous maternal plasma and resistant to breast milk neutralization. Infant T/F Env-pseudoviruses were equally sensitive to neutralization by broadly-neutralizing monoclonal and polyclonal antibodies as compared to nontransmitted breast milk Env variants. Conclusion Postnatally-T/F Env variants do not appear to possess a superior ability to interact with and cross a mucosal barrier or an exceptional resistance to neutralization that define their capability to initiate infection across the infant gastrointestinal tract in the setting of preexisting maternal antibodies.
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Affiliation(s)
- Genevieve G Fouda
- Human Vaccine Institute, Duke University Medical Center, Durham, NC, USA
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4
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Neutralizing antibodies inhibit HIV-1 transfer from primary dendritic cells to autologous CD4 T lymphocytes. Blood 2012; 120:3708-17. [DOI: 10.1182/blood-2012-03-418913] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractDendritic cells (DCs) support only low levels of HIV-1 replication, but have been shown to transfer infectious viral particles highly efficiently to neighboring permissive CD4 T lymphocytes. This mode of cell-to-cell HIV-1 spread may be a predominant mode of infection and dissemination. In the present study, we analyzed the kinetics of fusion, replication, and the ability of HIV-1–specific Abs to inhibit HIV-1 transfer from immature DCs to autologous CD4 T lymphocytes. We found that neutralizing mAbs prevented HIV-1 transfer to CD4 T lymphocytes in trans and in cis, whereas nonneutralizing Abs did not. Neutralizing Abs also significantly decreased HIV-1 replication in DCs, even when added 2 hours after HIV-1 infection. Interestingly, a similar inhibition of HIV-1 replication in DCs was detected with some nonneutralizing Abs and was correlated with DC maturation. We suggest that the binding of HIV-1-specific Abs to FcγRs leads to HIV-1 inhibition in DCs by triggering DC maturation. This efficient inhibition of HIV-1 transfer by Abs highlights the importance of inducing HIV-specific Abs by vaccination directly at the mucosal portal of HIV-1 entry to prevent early dissemination after sexual transmission.
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Gift SK, McFadden K, Zentner IJ, Rajagopal S, Zhang MY, Dimitrov DS, Chaiken IM. Monoclonal Antibody m18 Paratope Leading to Dual Receptor Antagonism of HIV-1 gp120. Biochemistry 2011; 50:2769-79. [DOI: 10.1021/bi101161j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | - Mei-Yun Zhang
- AIDS Institute, Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Dimiter S. Dimitrov
- Center for Cancer Research Nanobiology Program, CCR, NCI-Frederick, National Institutes of Health, Frederick, Maryland 21702, United States
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6
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Gift SK, Zentner IJ, Schön A, McFadden K, Umashankara M, Rajagopal S, Contarino M, Duffy C, Courter JR, Zhang MY, Gershoni JM, Cocklin S, Dimitrov DS, Smith AB, Freire E, Chaiken IM. Conformational and structural features of HIV-1 gp120 underlying the dual receptor antagonism by cross-reactive neutralizing antibody m18. Biochemistry 2011; 50:2756-68. [PMID: 21351734 DOI: 10.1021/bi101160r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigated the interaction between cross-reactive HIV-1 neutralizing human monoclonal antibody m18 and HIV-1YU-2 gp120 in an effort to understand how this antibody inhibits the entry of virus into cells. m18 binds to gp120 with high affinity (KD≈5 nM) as measured by surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). SPR analysis further showed that m18 inhibits interactions of gp120 with both soluble CD4 and CD4-induced antibodies that have epitopes overlapping the coreceptor binding site. This dual receptor site antagonism, which occurs with equal potency for both inhibition effects, argues that m18 is not functioning as a mimic of CD4, in spite of the presence of a putative CD4-like loop formed by HCDR3 in the antibody. Consistent with this view, m18 was found to interact with gp120 in the presence of saturating concentrations of a CD4-mimicking small molecule gp120 inhibitor, suggesting that m18 does not require unoccupied CD4 Phe43 binding cavity residues of gp120. Thermodynamic analysis of the m18-gp120 interaction suggests that m18 stabilizes a conformation of gp120 that is unique from and less structured than the CD4-stabilized conformation. Conformational mutants of gp120 were studied for their impact on m18 interaction. Mutations known to disrupt the coreceptor binding region and to lead to complete suppression of 17b binding had minimal effects on m18 binding. This argues that energetically important epitopes for m18 binding lie outside the disrupted bridging sheet region used for 17b and coreceptor binding. In contrast, mutations in the CD4 region strongly affected m18 binding. Overall, the results obtained in this work argue that m18, rather than mimicking CD4 directly, suppresses both receptor binding site functions of HIV-1 gp120 by stabilizing a nonproductive conformation of the envelope protein. These results can be related to prior findings about the importance of conformational entrapment as a common mode of action for neutralizing CD4bs antibodies, with differences mainly in epitope utilization and the extent of gp120 structuring.
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Affiliation(s)
- Syna Kuriakose Gift
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
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7
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Enríquez-Navas PM, Marradi M, Padro D, Angulo J, Penadés S. A solution NMR study of the interactions of oligomannosides and the anti-HIV-1 2G12 antibody reveals distinct binding modes for branched ligands. Chemistry 2011; 17:1547-60. [PMID: 21268157 DOI: 10.1002/chem.201002519] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Indexed: 12/23/2022]
Abstract
The structural and affinity details of the interactions of synthetic oligomannosides, linear (di-, tri-, and tetra-) and branched (penta- and hepta-), with the broadly neutralizing anti-HIV-1 antibody 2G12 (HIV=human immunodeficiency virus) have been investigated in solution by using ligand-based NMR techniques, specifically saturation transfer difference (STD) NMR spectroscopy and transferred NOE experiments. Linear oligomannosides show similar binding modes to the antibody, with the nonreducing terminal disaccharide Manα(1→2)Man (Man=mannose) making the closest protein/ligand contacts in the bound state. In contrast, the branched pentamannoside shows two alternate binding modes, involving both ligand arms (D2- and D3-like), a dual binding description of the molecular recognition of this ligand by 2G12 in solution that differs from the single binding mode deduced from X-ray studies. On the contrary, the antibody shows an unexpected selectivity for one arm (D1-like) of the other branched ligand (heptamannoside). This result explains the previously reported lack of affinity enhancement relative to that of the D1-like tetramannoside. Single-ligand STD NMR titration experiments revealed noticeable differences in binding affinities among the linear and branched ligands in solution, with the latter showing decreased affinity. Among the analyzed series of ligands, the strongest 2G12 binders were the linear tri- and tetramannosides because both show similar affinity for the antibody. These results demonstrate that NMR spectroscopic techniques can deliver abundant structural, dynamics, and affinity information for the characterization of oligomannose-2G12 binding in solution, thus complementing, and, as in the case of the pentamannoside, extending, the structural view from X-ray crystallography. This information is of key importance for the development of multivalent synthetic gp120 high-mannose glycoconjugate mimics in the context of vaccine development.
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Affiliation(s)
- Pedro M Enríquez-Navas
- Laboratory of GlycoNanotechnology, Biofunctional Nanomaterial Unit, CIC biomaGUNE, Parque Tecnológico, Paseo de Miramón 182, 20009 San Sebastián, Spain
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8
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Wen M, Arora R, Wang H, Liu L, Kimata JT, Zhou P. GPI-anchored single chain Fv--an effective way to capture transiently-exposed neutralization epitopes on HIV-1 envelope spike. Retrovirology 2010; 7:79. [PMID: 20923574 PMCID: PMC2959034 DOI: 10.1186/1742-4690-7-79] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 10/06/2010] [Indexed: 12/22/2022] Open
Abstract
Background Identification of broad neutralization epitopes in HIV-1 envelope spikes is paramount for HIV-1 vaccine development. A few broad neutralization epitopes identified so far are present on the surface of native HIV-1 envelope spikes whose recognition by antibodies does not depend on conformational changes of the envelope spikes. However, HIV-1 envelope spikes also contain transiently-exposed neutralization epitopes, which are more difficult to identify. Results In this study, we constructed single chain Fvs (scFvs) derived from seven human monoclonal antibodies and genetically linked them with or without a glycosyl-phosphatidylinositol (GPI) attachment signal. We show that with a GPI attachment signal the scFvs are targeted to lipid rafts of plasma membranes. In addition, we demonstrate that four of the GPI-anchored scFvs, but not their secreted counterparts, neutralize HIV-1 with various degrees of breadth and potency. Among them, GPI-anchored scFv (X5) exhibits extremely potent and broad neutralization activity against multiple clades of HIV-1 strains tested. Moreover, we show that GPI-anchored scFv (4E10) also exhibited more potent neutralization activity than its secretory counterpart. Finally, we demonstrate that expression of GPI-anchored scFv (X5) in the lipid raft of plasma membrane of human CD4+ T cells confers long-term resistance to HIV-1 infection, HIV-1 envelope-mediated cell-cell fusion, and the infection of HIV-1 captured and transferred by human DCs. Conclusions Thus GPI-anchored scFv could be used as a general and effective way to identify antibodies that react with transiently-exposed neutralization epitopes in envelope proteins of HIV-1 and other enveloped viruses. The GPI-anchored scFv (X5), because of its breadth and potency, should have a great potential to be developed into anti-viral agent for HIV-1 prevention and therapy.
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Affiliation(s)
- Michael Wen
- The Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200025, China
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9
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Binley JM, Ban YEA, Crooks ET, Eggink D, Osawa K, Schief WR, Sanders RW. Role of complex carbohydrates in human immunodeficiency virus type 1 infection and resistance to antibody neutralization. J Virol 2010; 84:5637-55. [PMID: 20335257 PMCID: PMC2876609 DOI: 10.1128/jvi.00105-10] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 03/15/2010] [Indexed: 11/20/2022] Open
Abstract
Complex N-glycans flank the receptor binding sites of the outer domain of HIV-1 gp120, ostensibly forming a protective "fence" against antibodies. Here, we investigated the effects of rebuilding this fence with smaller glycoforms by expressing HIV-1 pseudovirions from a primary isolate in a human cell line lacking N-acetylglucosamine transferase I (GnTI), the enzyme that initiates the conversion of oligomannose N-glycans into complex N-glycans. Thus, complex glycans, including those that surround the receptor binding sites, are replaced by fully trimmed oligomannose stumps. Conversely, the untrimmed oligomannoses of the silent domain of gp120 are likely to remain unchanged. For comparison, we produced a mutant virus lacking a complex N-glycan of the V3 loop (N301Q). Both variants exhibited increased sensitivities to V3 loop-specific monoclonal antibodies (MAbs) and soluble CD4. The N301Q virus was also sensitive to "nonneutralizing" MAbs targeting the primary and secondary receptor binding sites. Endoglycosidase H treatment resulted in the removal of outer domain glycans from the GnTI- but not the parent Env trimers, and this was associated with a rapid and complete loss in infectivity. Nevertheless, the glycan-depleted trimers could still bind to soluble receptor and coreceptor analogs, suggesting a block in post-receptor binding conformational changes necessary for fusion. Collectively, our data show that the antennae of complex N-glycans serve to protect the V3 loop and CD4 binding site, while N-glycan stems regulate native trimer conformation, such that their removal can lead to global changes in neutralization sensitivity and, in extreme cases, an inability to complete the conformational rearrangements necessary for infection.
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Affiliation(s)
- James M Binley
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, USA.
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10
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Zhou N, Fan L, Ho HT, Nowicka-Sans B, Sun Y, Zhu Y, Hu Y, McAuliffe B, Rose B, Fang H, Wang T, Kadow J, Krystal M, Alexander L, Colonno R, Lin PF. Increased sensitivity of HIV variants selected by attachment inhibitors to broadly neutralizing antibodies. Virology 2010; 402:256-61. [PMID: 20400170 DOI: 10.1016/j.virol.2010.03.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 01/20/2010] [Accepted: 03/18/2010] [Indexed: 11/30/2022]
Abstract
Treatment with HIV attachment inhibitors (AIs) can select for escape mutants throughout the viral envelope. We report on three such mutations: F423Y (gp120 CD4 binding pocket) and I595F and K655E (gp41 ectodomain). Each displayed decreased sensitivity to the AI BMS-488043 and earlier generation AIs, along with increased sensitivity to the broadly neutralizing antibodies 2F5 and 4E10, without affecting the rate of viral entry or sensitivity to the entry inhibitors AMD-3100 and Enfuvirtide. We also observed that I595F did not substantially increase envelope sensitivity to HIV-infected patient sera. Based on these observations, we propose that although F423Y, I595F and K655E may all affect the presentation of the 2F5 and 4E10 epitopes, natural immune mimicry is rare only for the I595F effect. Thus, it seems that in addition to restricting AI resistance development, incorporation of I595F into an appropriate vehicle could elicit a novel antiviral response to improve vaccine efficacy.
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Affiliation(s)
- Nannan Zhou
- Department of Virology, 5 Department of Research Parkway, Wallingford, CT 06498, USA
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11
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Eggink D, Melchers M, Wuhrer M, van Montfort T, Dey AK, Naaijkens BA, David KB, Le Douce V, Deelder AM, Kang K, Olson WC, Berkhout B, Hokke CH, Moore JP, Sanders RW. Lack of complex N-glycans on HIV-1 envelope glycoproteins preserves protein conformation and entry function. Virology 2010; 401:236-47. [PMID: 20304457 DOI: 10.1016/j.virol.2010.02.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 12/23/2009] [Accepted: 02/13/2010] [Indexed: 10/19/2022]
Abstract
The HIV-1 envelope glycoprotein complex (Env) is the focus of vaccine development aimed at eliciting humoral immunity. Env's extensive and heterogeneous N-linked glycosylation affects folding, binding to lectin receptors, antigenicity and immunogenicity. We characterized recombinant Env proteins and virus particles produced in mammalian cells that lack N-acetylglucosaminyltransferase I (GnTI), an enzyme necessary for the conversion of oligomannose N-glycans to complex N-glycans. Carbohydrate analyses revealed that trimeric Env produced in GnTI(-/-) cells contained exclusively oligomannose N-glycans, with incompletely trimmed oligomannose glycans predominating. The folding and conformation of Env proteins was little affected by the manipulation of the glycosylation. Viruses produced in GnTI(-/-) cells were infectious, indicating that the conversion to complex glycans is not necessary for Env entry function, although virus binding to the C-type lectin DC-SIGN was enhanced. Manipulating Env's N-glycosylation may be useful for structural and functional studies and for vaccine design.
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Affiliation(s)
- Dirk Eggink
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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12
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Hessell AJ, Rakasz EG, Poignard P, Hangartner L, Landucci G, Forthal DN, Koff WC, Watkins DI, Burton DR. Broadly neutralizing human anti-HIV antibody 2G12 is effective in protection against mucosal SHIV challenge even at low serum neutralizing titers. PLoS Pathog 2009; 5:e1000433. [PMID: 19436712 PMCID: PMC2674935 DOI: 10.1371/journal.ppat.1000433] [Citation(s) in RCA: 412] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 04/16/2009] [Indexed: 11/27/2022] Open
Abstract
Developing an immunogen that elicits broadly neutralizing antibodies (bNAbs) is an elusive but important goal of HIV vaccine research, especially after the recent failure of the leading T cell based HIV vaccine in human efficacy trials. Even if such an immunogen can be developed, most animal model studies indicate that high serum neutralizing concentrations of bNAbs are required to provide significant benefit in typical protection experiments. One possible exception is provided by the anti-glycan bNAb 2G12, which has been reported to protect macaques against CXCR4-using SHIV challenge at relatively low serum neutralizing titers. Here, we investigated the ability of 2G12 administered intravenously (i.v.) to protect against vaginal challenge of rhesus macaques with the CCR5-using SHIVSF162P3. The results show that, at 2G12 serum neutralizing titers of the order of 1∶1 (IC90), 3/5 antibody-treated animals were protected with sterilizing immunity, i.e. no detectable virus replication following challenge; one animal showed a delayed and lowered primary viremia and the other animal showed a course of infection similar to 4 control animals. This result contrasts strongly with the typically high titers observed for protection by other neutralizing antibodies, including the bNAb b12. We compared b12 and 2G12 for characteristics that might explain the differences in protective ability relative to neutralizing activity. We found no evidence to suggest that 2G12 transudation to the vaginal surface was significantly superior to b12. We also observed that the ability of 2G12 to inhibit virus replication in target cells through antibody-mediated effector cell activity in vitro was equivalent or inferior to b12. The results raise the possibility that some epitopes on HIV may be better vaccine targets than others and support targeting the glycan shield of the envelope. An effective HIV vaccine should elicit broadly neutralizing antibodies, i.e. antibodies that neutralize a wide spectrum of different HIVs in vitro. A number of human monoclonal antibodies have been isolated with broad neutralization and shown to protect macaques against vaginal HIV challenge. Protection is generally correlated with neutralization and requires relatively high antibody concentrations that may be difficult to achieve by vaccination. Here, we show that one monoclonal antibody (2G12) is unusually potent in protection relative to its neutralizing ability as hinted at by earlier data. Further studies eliminate an unusual ability of 2G12 to be transported to the vagina (site of infection) as a possible explanation for our observations. Although the precise mechanism is unclear, the studies have important implications for HIV vaccine design in general by suggesting that some vaccine targets on HIV may be better than others and, specifically, by suggesting that the sugar coat of HIV may be a particularly rewarding target if appropriate immunogens can be designed.
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Affiliation(s)
- Ann J. Hessell
- Department of Immunology and Microbial Science, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California, United States of America
| | - Eva G. Rakasz
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Pascal Poignard
- Department of Immunology and Microbial Science, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California, United States of America
- International AIDS Vaccine Initiative (IAVI), New York, New York, United States of America
| | - Lars Hangartner
- Department of Immunology and Microbial Science, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California, United States of America
- Institute of Medical Virology, University of Zürich, Zürich, Switzerland
| | - Gary Landucci
- Division of Infectious Diseases, Department of Medicine, UC Irvine School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Donald N. Forthal
- Division of Infectious Diseases, Department of Medicine, UC Irvine School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Wayne C. Koff
- International AIDS Vaccine Initiative (IAVI), New York, New York, United States of America
| | - David I. Watkins
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Dennis R. Burton
- Department of Immunology and Microbial Science, and IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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A yeast glycoprotein shows high-affinity binding to the broadly neutralizing human immunodeficiency virus antibody 2G12 and inhibits gp120 interactions with 2G12 and DC-SIGN. J Virol 2009; 83:4861-70. [PMID: 19264785 DOI: 10.1128/jvi.02537-08] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) envelope (Env) protein contains numerous N-linked carbohydrates that shield conserved peptide epitopes and promote trans infection by dendritic cells via binding to cell surface lectins. The potent and broadly neutralizing monoclonal antibody 2G12 binds a cluster of high-mannose-type oligosaccharides on the gp120 subunit of Env, revealing a conserved and highly exposed epitope on the glycan shield. To find an effective antigen for eliciting 2G12-like antibodies, we searched for endogenous yeast proteins that could bind to 2G12 in a panel of Saccharomyces cerevisiae glycosylation knockouts and discovered one protein that bound weakly in a Delta pmr1 strain deficient in hyperglycosylation. 2G12 binding to this protein, identified as Pst1, was enhanced by adding the Delta mnn1 deletion to the Delta pmr1 background, ensuring the exposure of terminal alpha1,2-linked mannose residues on the D1 and D3 arms of high-mannose glycans. However, optimum 2G12 antigenicity was found when Pst1, a heavily N-glycosylated protein, was expressed with homogenous Man(8)GlcNAc(2) structures in Delta och1 Delta mnn1 Delta mnn4 yeast. Surface plasmon resonance analysis of this form of Pst1 showed high affinity for 2G12, which translated into Pst1 efficiently inhibiting gp120 interactions with 2G12 and DC-SIGN and blocking 2G12-mediated neutralization of HIV-1 pseudoviruses. The high affinity of the yeast glycoprotein Pst1 for 2G12 highlights its potential as a novel antigen to induce 2G12-like antibodies.
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Borna disease virus requires cholesterol in both cellular membrane and viral envelope for efficient cell entry. J Virol 2009; 83:2655-62. [PMID: 19129439 DOI: 10.1128/jvi.02206-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borna disease virus (BDV), the prototypic member of the family Bornaviridae within the order Mononegavirales, provides an important model for the investigation of viral persistence within the central nervous system (CNS) and of associated brain disorders. BDV is highly neurotropic and enters its target cell via receptor-mediated endocytosis, a process mediated by the virus surface glycoprotein (G), but the cellular factors and pathways determining BDV cell tropism within the CNS remain mostly unknown. Cholesterol has been shown to influence viral infections via its effects on different viral processes, including replication, budding, and cell entry. In this work, we show that cell entry, but not replication and gene expression, of BDV was drastically inhibited by depletion of cellular cholesterol levels. BDV G-mediated attachment to BDV-susceptible cells was cholesterol independent, but G localized to lipid rafts (LR) at the plasma membrane. LR structure and function critically depend on cholesterol, and hence, compromised structural integrity and function of LR caused by cholesterol depletion likely inhibited the initial stages of BDV cell internalization. Furthermore, we also show that viral-envelope cholesterol is required for BDV infectivity.
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Crooks ET, Jiang P, Franti M, Wong S, Zwick MB, Hoxie JA, Robinson JE, Moore PL, Binley JM. Relationship of HIV-1 and SIV envelope glycoprotein trimer occupation and neutralization. Virology 2008; 377:364-78. [PMID: 18539308 DOI: 10.1016/j.virol.2008.04.045] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 03/21/2008] [Accepted: 04/24/2008] [Indexed: 11/26/2022]
Abstract
Insights into the process of HIV-1 neutralization may assist rational vaccine design. Here, we compared antibody neutralization against the JR-FL primary isolate and trimer binding affinities judged by native PAGE. Monovalent Fab-trimer binding and neutralization showed a direct quantitative relationship, implying that neutralization begins as each trimer is occupied by one antibody. At saturation, three Fab or soluble CD4 molecules engaged each trimer. In contrast, a maximum of one soluble CD4 molecule bound to functional SIV trimers with a truncated a gp41 tail. Remarkably, soluble CD4 was found to trigger dramatic enhancement of this virus. Unlike Fabs, a quantitative correlation between JR-FL trimer binding and neutralization was unclear for some, but not all IgGs, as neutralization was markedly increased, but trimer affinity was largely unchanged. In addition, only one molecule of certain gp41-specific IgGs appeared to be able to bind each trimer. We discuss the implications of these findings in weighing the relative contributions of size, multivalent binding and other possible effects of IgGs to explain their increased potency.
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Affiliation(s)
- Emma T Crooks
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, USA
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The C-type lectin surface receptor DCIR acts as a new attachment factor for HIV-1 in dendritic cells and contributes to trans- and cis-infection pathways. Blood 2008; 112:1299-307. [PMID: 18541725 DOI: 10.1182/blood-2008-01-136473] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The dynamic interplay between dendritic cells (DCs) and human immunodeficiency virus type-1 (HIV-1) is thought to result in viral dissemination and evasion of antiviral immunity. Although initial observations suggested that the C-type lectin receptor (CLR) DC-SIGN was responsible for the trans-infection function of the virus, subsequent studies demonstrated that trans-infection of CD4(+) T cells with HIV-1 can also occur through DC-SIGN-independent mechanisms. We demonstrate that a cell surface molecule designated DCIR (for DC immunoreceptor), a member of a recently described family of DC-expressing CLRs, can participate in the capture of HIV-1 and promote infection in trans and in cis of autologous CD4(+) T cells from human immature monocyte-derived DCs. The contribution of DCIR to these processes was revealed using DCIR-specific siRNAs and a polyclonal antibody specific for the carbohydrate recognition domain of DCIR. Data from transfection experiments indicated that DCIR acts as a ligand for HIV-1 and is involved in events leading to productive virus infection. Finally, we show that the neck domain of DCIR is important for the DCIR-mediated effect on virus binding and infection. These results point to a possible role for DCIR in HIV-1 pathogenesis by supporting the productive infection of DCs and promoting virus propagation.
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Dendritic cells preferentially transfer CXCR4-using human immunodeficiency virus type 1 variants to CD4+ T lymphocytes in trans. J Virol 2008; 82:7886-96. [PMID: 18524826 DOI: 10.1128/jvi.00245-08] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) preferentially utilizes the CCR5 coreceptor for target cell entry in the acute phase of infection, while later in disease progression the virus switches to the CXCR4 coreceptor in approximately 50% of patients. In response to HIV-1 the adaptive immune response is triggered, and antibody (Ab) production is elicited to block HIV-1 entry. We recently determined that dendritic cells (DCs) can efficiently capture Ab-neutralized HIV-1, restore infectivity, and transmit infectious virus to target cells. Here, we tested the effect of Abs on trans transmission of CCR5 or CXCR4 HIV-1 variants. We observed that transmission of HIV-1 by immature as well as mature DCs was significantly higher for CXCR4- than CCR5-tropic viral strains. Additionally, neutralizing Abs directed against either the gp41 or gp120 region of the envelope such as 2F5, 4E10, and V3-directed Abs inhibited transmission of CCR5-tropic HIV-1, whereas Ab-treated CXCR4-tropic virus demonstrated unaltered or increased transmission. To further study the effects of coreceptor usage we tested molecularly cloned HIV-1 variants with modifications in the envelope that were based on longitudinal gp120 V1 and V3 variable loop sequences from a patient progressing to AIDS. We observed that DCs preferentially facilitated infection of CD4(+) T lymphocytes of viral strains with an envelope phenotype found late in disease. Taken together, our results illustrate that DCs transmit CXCR4-tropic HIV-1 much more efficiently than CCR5 strains; we hypothesize that this discrimination could contribute to the in vivo coreceptor switch after seroconversion and could be responsible for the increase in viral load.
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Marzi A, Mitchell DA, Chaipan C, Fisch T, Doms RW, Carrington M, Desrosiers RC, Pöhlmann S. Modulation of HIV and SIV neutralization sensitivity by DC-SIGN and mannose-binding lectin. Virology 2007; 368:322-30. [PMID: 17659761 DOI: 10.1016/j.virol.2007.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 05/01/2007] [Accepted: 07/03/2007] [Indexed: 12/17/2022]
Abstract
The C-type lectin DC-SIGN binds to oligosaccharides on the human and simian immunodeficiency virus (HIV, SIV) envelope glycoproteins and promotes infection of susceptible cells. Here, we show that DC-SIGN recognizes glycans involved in SIV sensitivity to neutralizing antibodies and that binding to DC-SIGN confers neutralization resistance to an otherwise sensitive SIV variant. Moreover, we provide evidence that mannose-binding lectin (MBL) can interfere with HIV-1 neutralization by the carbohydrate-specific antibody 2G12.
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Affiliation(s)
- Andrea Marzi
- Institute for Clinical and Molecular Virology, University Hospital Erlangen, 91054 Erlangen, Germany
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Dunfee RL, Thomas ER, Wang J, Kunstman K, Wolinsky SM, Gabuzda D. Loss of the N-linked glycosylation site at position 386 in the HIV envelope V4 region enhances macrophage tropism and is associated with dementia. Virology 2007; 367:222-34. [PMID: 17599380 PMCID: PMC2201988 DOI: 10.1016/j.virol.2007.05.029] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 05/14/2007] [Accepted: 05/23/2007] [Indexed: 11/17/2022]
Abstract
HIV infects macrophages and microglia in the central nervous system (CNS). Mechanisms that enhance HIV macrophage/microglial tropism are not well understood. Here, we identify an HIV Env variant in the V4 region of gp120, Asp 386 (D386), that eliminates an N-linked glycosylation site at position 386, enhances viral replication in macrophages, and is present at a higher frequency in AIDS patients with HIV-associated dementia (HAD) compared with non-HAD patients. D386 enhances HIV entry and replication in macrophages but not in microglia or peripheral blood mononuclear cells, possibly due to differential glycosylation in these cell types. A D386N mutation in the UK1br Env, which restores the N-linked glycan site, reduced neutralization sensitivity to the IgG1b12 (b12) monoclonal antibody, which recognizes a conserved neutralization epitope that overlaps the CD4 binding site. Molecular modeling suggested that loss of the glycan at position 386 increases exposure of the CD4 and b12 binding sites on gp120. Loss of a glycan at 386 was more frequent in Envs from HAD patients (26%; n=185) compared with non-HAD patients (7%; n=99; p<0.001). The most significant association of these Env variants with HAD was in blood or lymphoid tissue rather than brain. These findings suggest that increased exposure of the b12 epitope overlapping the CD4 binding site via elimination of a glycan at position 386 is associated with enhanced HIV macrophage tropism, and provide evidence that determinants of macrophage and microglia tropism are overlapping but distinct.
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Affiliation(s)
- Rebecca L. Dunfee
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Elaine R. Thomas
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Jianbin Wang
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Kevin Kunstman
- Department of Medicine, Northwestern University Medical School, Chicago, IL, USA
| | - Steven M. Wolinsky
- Department of Medicine, Northwestern University Medical School, Chicago, IL, USA
| | - Dana Gabuzda
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Corresponding Author. Mailing Address: Dana-Farber Cancer Institute, JFB 816, 44 Binney St., Boston, MA 02115, Phone: (617) 632-2154, Fax: (617) 632 3113, E-mail:
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Hong PWP, Nguyen S, Young S, Su SV, Lee B. Identification of the optimal DC-SIGN binding site on human immunodeficiency virus type 1 gp120. J Virol 2007; 81:8325-36. [PMID: 17522223 PMCID: PMC1951277 DOI: 10.1128/jvi.01765-06] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) envelope (gp120) binding to DC-SIGN, a C-type lectin that can facilitate HIV infection in cis and in trans, is largely dependent on high-mannose-content moieties. Here, we delineate the N-linked glycosylation (N-glycan) sites in gp120 that contribute to optimal DC-SIGN binding. Soluble DC-SIGN was able to block 2G12 binding to gp120, but not vice versa, suggesting that DC-SIGN binds to a more flexible combination of N-glycans than 2G12. Consistent with this observation, HIV strain JRCSF gp120 prebound to 2G12 was 10-fold more sensitive to mannan competition than gp120 that was not prebound in a DC-SIGN cell surface binding assay. The analysis of multiple mutant forms of the 2G12 epitope revealed one triple glycosylation mutant form, termed 134mut (carrying N293Q, N382Q, and N388Q mutations), that exhibited a significant increase in sensitivity to both mannan competition and endoglycosidase H digestion compared to that of the 124mut form (carrying N293Q, N328Q, and N388Q mutations) and wild-type gp120 in a DC-SIGN binding assay. Importantly, no such differences were observed when binding to Galanthus nivalis was assessed. The 134mut form of gp120 also exhibited decreased binding to DC-SIGN in the context of native envelope spikes on a virion, and virus bearing 134mut exhibited less efficient DC-SIGN-mediated infection in trans. Significantly, 124mut and 134mut differed by only one glycosylation site mutation in each construct, and both 124mut and 134mut viruses exhibited wild-type levels of infectivity when used in a direct infection assay. In summary, while DC-SIGN can bind to a flexible combination of N-glycans on gp120, its optimal binding site overlaps with specific N-glycans within the 2G12 epitope. Conformationally intact envelopes that are DC-SIGN binding deficient can be used to probe the in vivo biological functions of DC-SIGN.
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Affiliation(s)
- Patrick W-P Hong
- Department of Microbiology, Immunology, and Molecular Genetics, 3825 MSB, UCLA, 609 Charles E. Young Dr. East, Los Angeles, CA 90095, USA
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Chen H, Xu X, Jones IM. Immunogenicity of the outer domain of a HIV-1 clade C gp120. Retrovirology 2007; 4:33. [PMID: 17509143 PMCID: PMC1891314 DOI: 10.1186/1742-4690-4-33] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Accepted: 05/17/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The possibility that a sub domain of a C clade HIV-1 gp120 could act as an effective immunogen was investigated. To do this, the outer domain (OD) of gp120CN54 was expressed and characterized in a construct marked by a re-introduced conformational epitope for MAb 2G12. The expressed sequence showed efficient epitope retention on the isolated ODCN54 suggesting authentic folding. To facilitate purification and subsequent immunogenicity ODCN54 was fused to the Fc domain of human IgG1. Mice were immunised with the resulting fusion proteins and also with gp120CN54-Fc and gp120 alone. RESULTS Fusion to Fc was found to stimulate antibody titre and Fc tagged ODCN54 was substantially more immunogenic than non-tagged gp120. Immunogenicity appeared the result of Fc facilitated antigen processing as immunisation with an Fc domain mutant that reduced binding to the FcR lead to a reduction in antibody titre when compared to the parental sequence. The breadth of the antibody response was assessed by serum reaction with five overlapping fragments of gp120CN54 expressed as GST fusion proteins in bacteria. A predominant anti-inner domain and anti-V3C3 response was observed following immunisation with gp120CN54-Fc and an anti-V3C3 response to the ODCN54-Fc fusion. CONCLUSION The outer domain of gp120CN54 is correctly folded following expression as a C terminal fusion protein. Immunogenicity is substantial when targeted to antigen presenting cells but shows V3 dominance in the polyvalent response. The gp120 outer domain has potential as a candidate vaccine component.
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Affiliation(s)
- Hongying Chen
- School of Biological Sciences, The University of Reading, Reading, RG6 6AJ, UK
| | - Xiaodong Xu
- School of Biological Sciences, The University of Reading, Reading, RG6 6AJ, UK
| | - Ian M Jones
- School of Biological Sciences, The University of Reading, Reading, RG6 6AJ, UK
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Binley JM, Ngo-Abdalla S, Moore P, Bobardt M, Chatterji U, Gallay P, Burton DR, Wilson IA, Elder JH, de Parseval A. Erratum to: Inhibition of HIV Env binding to cellular receptors by monoclonal antibody 2G12 as probed by Fc-tagged gp120. Retrovirology 2007. [PMCID: PMC1847835 DOI: 10.1186/1742-4690-4-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Naarding MA, Baan E, Pollakis G, Paxton WA. Effect of chloroquine on reducing HIV-1 replication in vitro and the DC-SIGN mediated transfer of virus to CD4+ T-lymphocytes. Retrovirology 2007; 4:6. [PMID: 17263871 PMCID: PMC1796897 DOI: 10.1186/1742-4690-4-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 01/30/2007] [Indexed: 12/18/2022] Open
Abstract
Background Chloroquine (CQ) has been shown to inhibit HIV-1 replication in vitro as well as in vivo and has been proposed to alter the glycosylation pattern of the gp120 envelope. These activities indicate that the compound can be used not only as an effective HIV-1 therapeutic agent but also as a modulator of the gp120 envelope protein structure enabling for the production of broader neutralizing Ab responses. Results We confirm here that HIV-1 replication on CD4+ T-lymphocytes can be reduced in the presence of CQ and show that the reduced replication is producer cell mediated, with viruses generated in the presence of CQ not being inhibited for subsequent infectivity and replication. By analysing the gp120 envelope protein sequences from viruses cultured long-term in the absence or presence of CQ we demonstrate variant evolution patterns. One noticeable change is the reduction in the number of potential N-linked glycosylation sites in the V3 region as well as within the 2G12 Ab binding and neutralization epitope. We also demonstrate that HIV-1 produced in the presence of CQ has a reduced capacity for transfer by Raji-DC-SIGN cells to CD4+ T-lymphocytes, indicating another means whereby virus transmission or replication may be reduced in vivo. Conclusion These results indicate that CQ should be considered as an HIV-1 therapeutic agent with its influence exerted through a number of mechanisms in vivo, including modulation of the gp120 structure.
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Affiliation(s)
- Marloes A Naarding
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Elly Baan
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Georgios Pollakis
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - William A Paxton
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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