251
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Nelson S, Jost CA, Xu Q, Ess J, Martin JE, Oliphant T, Whitehead SS, Durbin AP, Graham BS, Diamond MS, Pierson TC. Maturation of West Nile virus modulates sensitivity to antibody-mediated neutralization. PLoS Pathog 2008; 4:e1000060. [PMID: 18464894 PMCID: PMC2330159 DOI: 10.1371/journal.ppat.1000060] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Accepted: 04/09/2008] [Indexed: 02/06/2023] Open
Abstract
West Nile virions incorporate 180 envelope (E) proteins that orchestrate the process of virus entry and are the primary target of neutralizing antibodies. The E proteins of newly synthesized West Nile virus (WNV) are organized into trimeric spikes composed of pre-membrane (prM) and E protein heterodimers. During egress, immature virions undergo a protease-mediated cleavage of prM that results in a reorganization of E protein into the pseudo-icosahedral arrangement characteristic of mature virions. While cleavage of prM is a required step in the virus life cycle, complete maturation is not required for infectivity and infectious virions may be heterogeneous with respect to the extent of prM cleavage. In this study, we demonstrate that virion maturation impacts the sensitivity of WNV to antibody-mediated neutralization. Complete maturation results in a significant reduction in sensitivity to neutralization by antibodies specific for poorly accessible epitopes that comprise a major component of the human antibody response following WNV infection or vaccination. This reduction in neutralization sensitivity reflects a decrease in the accessibility of epitopes on virions to levels that fall below a threshold required for neutralization. Thus, in addition to a role in facilitating viral entry, changes in E protein arrangement associated with maturation modulate neutralization sensitivity and introduce an additional layer of complexity into humoral immunity against WNV. West Nile virus (WNV) virions incorporate 180 envelope (E) proteins that are the primary target of neutralizing antibodies. As newly formed WNV virions are released from infected cells, the E proteins undergo a significant organizational change associated with maturation into an infectious virus. However, this process is not always efficient, as populations of infectious WNV include virions that did not complete the maturation process and may be heterogeneous with respect to the arrangement of E proteins on the virion. In this study, we found that neutralization by antibodies specific for epitopes commonly recognized in vivo is strongly impacted by the maturation state of WNV. Our studies suggest that maturation of WNV reduces the accessibility of some, but not all, epitopes on the virion for antibody binding. Virions that retain some immature character can be neutralized by monoclonal antibodies that fail to block infection of populations of WNV composed solely of mature virions. Similar results were found using polyclonal human serum obtained from volunteers of two clinical trials of candidate WNV vaccines. These studies identify unappreciated aspects of the antigenic complexity of WNV and highlight the importance of understanding the heterogenous forms of WNV that may be introduced into or replicating within the host.
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Affiliation(s)
- Steevenson Nelson
- Viral Pathogenesis Section, Laboratory of Viral Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christiane A. Jost
- Viral Pathogenesis Section, Laboratory of Viral Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Qinq Xu
- Viral Pathogenesis Section, Laboratory of Viral Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jessica Ess
- Viral Pathogenesis Section, Laboratory of Viral Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Julie E. Martin
- Vaccine Research Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Theodore Oliphant
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Stephen S. Whitehead
- Laboratory of Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Anna P. Durbin
- Center for Immunization Research, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Barney S. Graham
- Vaccine Research Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michael S. Diamond
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Theodore C. Pierson
- Viral Pathogenesis Section, Laboratory of Viral Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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252
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Huang KC, Lee MC, Wu CW, Huang KJ, Lei HY, Cheng JW. Solution structure and neutralizing antibody binding studies of domain III of the dengue-2 virus envelope protein. Proteins 2008; 70:1116-9. [PMID: 18004779 DOI: 10.1002/prot.21806] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Kuo-Chun Huang
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 300, Taiwan
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253
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Binding of a neutralizing antibody to dengue virus alters the arrangement of surface glycoproteins. Nat Struct Mol Biol 2008; 15:312-7. [PMID: 18264114 DOI: 10.1038/nsmb.1382] [Citation(s) in RCA: 279] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Accepted: 01/04/2008] [Indexed: 01/04/2023]
Abstract
The monoclonal antibody 1A1D-2 has been shown to strongly neutralize dengue virus serotypes 1, 2 and 3, primarily by inhibiting attachment to host cells. A crystal structure of its antigen binding fragment (Fab) complexed with domain III of the viral envelope glycoprotein, E, showed that the epitope would be partially occluded in the known structure of the mature dengue virus. Nevertheless, antibody could bind to the virus at 37 degrees C, suggesting that the virus is in dynamic motion making hidden epitopes briefly available. A cryo-electron microscope image reconstruction of the virus:Fab complex showed large changes in the organization of the E protein that exposed the epitopes on two of the three E molecules in each of the 60 icosahedral asymmetric units of the virus. The changes in the structure of the viral surface are presumably responsible for inhibiting attachment to cells.
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254
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Lindesmith LC, Donaldson EF, LoBue AD, Cannon JL, Zheng DP, Vinje J, Baric RS. Mechanisms of GII.4 norovirus persistence in human populations. PLoS Med 2008; 5:e31. [PMID: 18271619 PMCID: PMC2235898 DOI: 10.1371/journal.pmed.0050031] [Citation(s) in RCA: 419] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 12/12/2007] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Noroviruses are the leading cause of viral acute gastroenteritis in humans, noted for causing epidemic outbreaks in communities, the military, cruise ships, hospitals, and assisted living communities. The evolutionary mechanisms governing the persistence and emergence of new norovirus strains in human populations are unknown. Primarily organized by sequence homology into two major human genogroups defined by multiple genoclusters, the majority of norovirus outbreaks are caused by viruses from the GII.4 genocluster, which was first recognized as the major epidemic strain in the mid-1990s. Previous studies by our laboratory and others indicate that some noroviruses readily infect individuals who carry a gene encoding a functional alpha-1,2-fucosyltransferase (FUT2) and are designated "secretor-positive" to indicate that they express ABH histo-blood group antigens (HBGAs), a highly heterogeneous group of related carbohydrates on mucosal surfaces. Individuals with defects in the FUT2 gene are termed secretor-negative, do not express the appropriate HBGA necessary for docking, and are resistant to Norwalk infection. These data argue that FUT2 and other genes encoding enzymes that regulate processing of the HBGA carbohydrates function as susceptibility alleles. However, secretor-negative individuals can be infected with other norovirus strains, and reinfection with the GII.4 strains is common in human populations. In this article, we analyze molecular mechanisms governing GII.4 epidemiology, susceptibility, and persistence in human populations. METHODS AND FINDINGS Phylogenetic analyses of the GII.4 capsid sequences suggested an epochal evolution over the last 20 y with periods of stasis followed by rapid evolution of novel epidemic strains. The epidemic strains show a linear relationship in time, whereby serial replacements emerge from the previous cluster. Five major evolutionary clusters were identified, and representative ORF2 capsid genes for each cluster were expressed as virus-like particles (VLPs). Using salivary and carbohydrate-binding assays, we showed that GII.4 VLP-carbohydrate ligand binding patterns have changed over time and include carbohydrates regulated by the human FUT2 and FUT3 pathways, suggesting that strain sensitivity to human susceptibility alleles will vary. Variation in surface-exposed residues and in residues that surround the fucose ligand interaction domain suggests that antigenic drift may promote GII.4 persistence in human populations. Evidence supporting antigenic drift was obtained by measuring the antigenic relatedness of GII.4 VLPs using murine and human sera and demonstrating strain-specific serologic and carbohydrate-binding blockade responses. These data suggest that the GII.4 noroviruses persist by altering their HBGA carbohydrate-binding targets over time, which not only allows for escape from highly penetrant host susceptibility alleles, but simultaneously allows for immune-driven selection in the receptor-binding region to facilitate escape from protective herd immunity. CONCLUSIONS Our data suggest that the surface-exposed carbohydrate ligand binding domain in the norovirus capsid is under heavy immune selection and likely evolves by antigenic drift in the face of human herd immunity. Variation in the capsid carbohydrate-binding domain is tolerated because of the large repertoire of similar, yet distinct HBGA carbohydrate receptors available on mucosal surfaces that could interface with the remodeled architecture of the capsid ligand-binding pocket. The continuing evolution of new replacement strains suggests that, as with influenza viruses, vaccines could be targeted that protect against norovirus infections, and that continued epidemiologic surveillance and reformulations of norovirus vaccines will be essential in the control of future outbreaks.
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Affiliation(s)
- Lisa C Lindesmith
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Eric F Donaldson
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Anna D LoBue
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jennifer L Cannon
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Du-Ping Zheng
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Jan Vinje
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ralph S Baric
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America
- * To whom correspondence should be addressed. E-mail:
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255
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Mehlhop E, Ansarah-Sobrinho C, Johnson S, Engle M, Fremont DH, Pierson TC, Diamond MS. Complement protein C1q inhibits antibody-dependent enhancement of flavivirus infection in an IgG subclass-specific manner. Cell Host Microbe 2008; 2:417-26. [PMID: 18078693 DOI: 10.1016/j.chom.2007.09.015] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 08/28/2007] [Accepted: 09/26/2007] [Indexed: 01/11/2023]
Abstract
Severe dengue virus infection can occur in humans with pre-existing antibodies against the virus. This observation led to the hypothesis that a subneutralizing antibody level in vivo can increase viral burden and cause more severe disease. Indeed, antibody-dependent enhancement of infection (ADE) in vitro has been described for multiple viruses, including the flaviviruses dengue virus and West Nile virus. Here, we demonstrate that the complement component C1q restricts ADE by anti-flavivirus IgG antibodies in an IgG subclass-specific manner in cell culture and in mice. IgG subclasses that avidly bind C1q induced minimal ADE in the presence of C1q. These findings add a layer of complexity for the analysis of humoral immunity and flavivirus infection.
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Affiliation(s)
- Erin Mehlhop
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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256
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Abd-El-Aziz AS, Carraher CE, Pittman CU, Zeldin M. Cisplatin Derivatives as Antiviral Agents. INORGANIC AND ORGANOMETALLIC MACROMOLECULES 2008. [PMCID: PMC7121272 DOI: 10.1007/978-0-387-72947-3_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The use of polymeric derivatives of cisplatin as antiviral drugs is reviewed. Some of these drugs inhibit a wide variety of both RNA and DNA viruses including those responsible for herpes, common colds, chickenpox, and smallpox. The desirability of polymeric drugs is described as is the mode(s) of action of cisplatin itself. A description of viruses and methods of combating viruses is presented. Included is a review of current antiviral agents as well as modes of action of these antiviral agents.
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Affiliation(s)
- Alaa S. Abd-El-Aziz
- The University of British Columbia, Okanagan, 3333 University Way, V1V 1V7 Kelowna, British Columbia Canada
| | - Charles E. Carraher
- Department of Chemistry & Biochemistry, Florida Atlantic University, 777 Glades Rd., 33431 Boca Raton, Florida USA
| | - Charles U. Pittman
- Department of Chemistry, Mississippi State University, 39762 Mississippi State, Mississippi USA
| | - Martel Zeldin
- Department of Chemistry, University of Richmond, 28 Westhampton Way, 23173 Richmond, Virginia USA
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257
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Abstract
West Nile virus (WNV) infection of mosquitoes, birds, and vertebrates continues to spread in the Western Hemisphere. In humans, WNV infects the central nervous system and causes severe disease, primarily in the immunocompromised and elderly. In this review we discuss the mechanisms by which antibody controls WNV infection. Recent virologic, immunologic, and structural experiments have enhanced our understanding on how antibodies neutralize WNV and protect against disease. These advances have significant implications for the development of novel antibody-based therapies and targeted vaccines.
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258
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Abstract
Antibodies, although critical for host defense against West Nile virus (WNV), can both neutralize and enhance viral infection. In this issue of Cell Host & Microbe, Pierson et al. dissect these opposing effects and demonstrate that, when 120 epitopes are available per WNV virion, approximately 25 are occupied by antibody at 50% neutralization. At lower occupancies, enhancement of infection dominates; at higher ones, neutralization ensues. These results are important for WNV vaccine design and for potential therapeutic use of antibodies to WNV.
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Affiliation(s)
- Per Johan Klasse
- Department of Microbiology and Immunology, Cornell University, Weill Medical College, 1300 York Avenue, Box 62, New York, NY 10021, USA.
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259
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Pierson TC, Xu Q, Nelson S, Oliphant T, Nybakken GE, Fremont DH, Diamond MS. The stoichiometry of antibody-mediated neutralization and enhancement of West Nile virus infection. Cell Host Microbe 2007; 1:135-45. [PMID: 18005691 DOI: 10.1016/j.chom.2007.03.002] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 01/29/2007] [Accepted: 03/12/2007] [Indexed: 11/17/2022]
Abstract
Antibody binding to the icosahedral arrangement of envelope proteins on the surface of flaviviruses can result in neutralization or enhancement of infection. We evaluated how many antibodies must bind to a given epitope on West Nile virus (WNV) to achieve neutralization. The most potent monoclonal antibodies (mAbs) block infection at concentrations that result in low occupancy of accessible sites on the virion, with neutralization occurring when as few as 30 of 180 envelope proteins are bound. In contrast, weakly neutralizing mAbs recognize fewer sites on the virion and require almost complete occupancy to inhibit WNV infection. For all mAbs studied, enhancement of infection is possible in cells bearing activating Fc-gamma receptors when the number of mAbs docked to the virion is not sufficient for neutralization. Thus, neutralization is best described by a model requiring "multiple hits" with the cumulative functional outcome determined by interplay between antibody affinity and epitope accessibility.
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Affiliation(s)
- Theodore C Pierson
- Viral Pathogenesis Section, Laboratory of Viral Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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260
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Lanzavecchia A, Corti D, Sallusto F. Human monoclonal antibodies by immortalization of memory B cells. Curr Opin Biotechnol 2007; 18:523-8. [PMID: 18063358 PMCID: PMC7127177 DOI: 10.1016/j.copbio.2007.10.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 10/22/2007] [Indexed: 12/11/2022]
Abstract
The administration of hyper immune sera to prevent or treat life-threatening infections is a remarkable milestone in medicine and biotechnology that has been achieved more than a century ago. Yet, the therapeutic use of monoclonal antibodies in this field has developed slowly over the last decades. Here we compare and contrast current methods to generate human monoclonal antibodies and highlight the advantages of exploiting the human antibody repertoire using a novel method that allows efficient immortalization and cloning of human memory B cells. This method, which has been successfully applied to isolate broadly neutralizing antibodies against SARS and H5N1 influenza viruses, is expected to accelerate the development of therapeutics in the field of infectious diseases not only by providing neutralizing antibodies for passive serotherapy, but also by generating relevant information for vaccine design.
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Affiliation(s)
- Antonio Lanzavecchia
- Institute for Research in Biomedicine, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland.
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261
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Martina BE, Koraka P, van den Doel P, van Amerongen G, Rimmelzwaan GF, Osterhaus ADME. Immunization with West Nile virus envelope domain III protects mice against lethal infection with homologous and heterologous virus. Vaccine 2007; 26:153-7. [PMID: 18069096 PMCID: PMC7127062 DOI: 10.1016/j.vaccine.2007.10.055] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 10/19/2007] [Accepted: 10/25/2007] [Indexed: 11/01/2022]
Abstract
The Japanese encephalitis virus (JEV) serocomplex-group consists of mosquito-borne flaviviruses, which include West Nile virus (WNV) and JEV, and both may cause severe encephalitis in humans. WNV has spread rapidly across the United States since its introduction in 1999 and its geographical distribution within the western hemisphere is expected to further expand, whereas, JEV is the most common cause of viral encephalitis in Southeast Asia, China and India. Currently, there is no registered human vaccine or specific therapy to prevent or treat WNV infection. Here we describe the efficacy of recombinant domain III (DIII) of WNV glycoprotein E in a mouse model. It induces high neutralizing antibody titers, as well as, protection against lethal WNV infection in C57BL/6 mice. This vaccine preparation also afforded partial protection against lethal JEV infection.
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Affiliation(s)
- Byron E Martina
- Erasmus Medical Center, Institute of Virology, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands
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262
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Maillard RA, Jordan M, Beasley DWC, Barrett ADT, Lee JC. Long range communication in the envelope protein domain III and its effect on the resistance of West Nile virus to antibody-mediated neutralization. J Biol Chem 2007; 283:613-622. [PMID: 17986445 DOI: 10.1074/jbc.m706031200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The envelope protein domain III (ED3) of West Nile virus is the major virus-specific neutralization domain and harbors most of the critical mutations that induce resistance against antibody-mediated neutralization. We investigated the molecular mechanisms of neutralization resistance by studying the biophysical perturbations of monoclonal antibody (mAb)-resistant mutations on ED3 wild type. Our results showed that although the solution structure between ED3 wild type and mutants was preserved, the mutations that confer the highest degree of resistance to mAbs showed low protein stability and high local dynamic motions. Interestingly, the latter was observed in regions outside the mutation sites, indicating long range communications within ED3. Thus, we hypothesized that the mechanisms involved in resistance to mAb neutralization may include, in addition to mutations in the epitope, long range effects among distant structural elements. This hypothesis is consistent with reported mutations in other flaviviruses whose surfaces are not exposed for the interaction with other macromolecules, yet they confer mAb neutralization resistance.
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Affiliation(s)
- Rodrigo A Maillard
- Department of Biochemistry and Molecular Biology, Galveston, Texas 77555-1055
| | - Matthew Jordan
- Department of Biochemistry and Molecular Biology, Galveston, Texas 77555-1055
| | - David W C Beasley
- Department of Microbiology and Immunology, Galveston, Texas 77555-1055; Department of Sealy Center for Vaccine Development, Galveston, Texas 77555-1055; Institute for Human Infections and Immunity, the University of Texas Medical Branch, Galveston, Texas 77555-1055
| | - Alan D T Barrett
- Department of Sealy Center for Vaccine Development, Galveston, Texas 77555-1055; Institute for Human Infections and Immunity, the University of Texas Medical Branch, Galveston, Texas 77555-1055; Department of Pathology, Galveston, Texas 77555-1055
| | - J Ching Lee
- Department of Biochemistry and Molecular Biology, Galveston, Texas 77555-1055.
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263
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Lai CJ, Goncalvez AP, Men R, Wernly C, Donau O, Engle RE, Purcell RH. Epitope determinants of a chimpanzee dengue virus type 4 (DENV-4)-neutralizing antibody and protection against DENV-4 challenge in mice and rhesus monkeys by passively transferred humanized antibody. J Virol 2007; 81:12766-74. [PMID: 17881450 PMCID: PMC2169078 DOI: 10.1128/jvi.01420-07] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The chimpanzee monoclonal antibody (MAb) 5H2 is specific for dengue virus type 4 (DENV-4) and neutralizes the virus at a high titer in vitro. The epitope detected by the antibody was mapped by sequencing neutralization escape variants of the virus. One variant contained a Lys174-Glu substitution and another contained a Pro176-Leu substitution in domain I of the DENV-4 envelope protein (E). These mutations reduced binding affinity for the antibody 18- to >100-fold. Humanized immunoglobulin G (IgG) 5H2, originally produced from an expression vector, has been shown to be a variant containing a nine-amino-acid deletion in the Fc region which completely ablates antibody-dependent enhancement of DENV replication in vitro. The variant MAb, termed IgG 5H2 deltaD, is particularly attractive for exploring its protective capacity in vivo. Passive transfer of IgG 5H2 deltaD at 20 microg/mouse afforded 50% protection of suckling mice against challenge with 25 50% lethal doses of mouse neurovirulent DENV-4 strain H241. Passive transfer of antibody to monkeys was conducted to demonstrate proof of concept for protection against DENV challenge. Monkeys that received 2 mg/kg of body weight of IgG 5H2 deltaD were completely protected against 100 50% monkey infectious doses (MID50) of DENV-4, as indicated by the absence of viremia and seroconversion. A DENV-4 escape mutant that contained a Lys174-Glu substitution identical to that found in vitro was isolated from monkeys challenged with 10(6) MID50 of DENV-4. This substitution was also present in all naturally occurring isolates belonging to DENV-4 genotype III. These studies have important implications for possible antibody-mediated prevention of DENV infection.
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Affiliation(s)
- Ching-Juh Lai
- Laboratory of Infectious Diseases, National Institutes of Health, 50 South Drive MSC 8005, Bethesda, MD 20892, USA.
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264
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Sukupolvi-Petty S, Austin SK, Purtha WE, Oliphant T, Nybakken GE, Schlesinger JJ, Roehrig JT, Gromowski GD, Barrett AD, Fremont DH, Diamond MS. Type- and subcomplex-specific neutralizing antibodies against domain III of dengue virus type 2 envelope protein recognize adjacent epitopes. J Virol 2007; 81:12816-26. [PMID: 17881453 PMCID: PMC2169112 DOI: 10.1128/jvi.00432-07] [Citation(s) in RCA: 215] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neutralization of flaviviruses in vivo correlates with the development of an antibody response against the viral envelope (E) protein. Previous studies demonstrated that monoclonal antibodies (MAbs) against an epitope on the lateral ridge of domain III (DIII) of the West Nile virus (WNV) E protein strongly protect against infection in animals. Based on X-ray crystallography and sequence analysis, an analogous type-specific neutralizing epitope for individual serotypes of the related flavivirus dengue virus (DENV) was hypothesized. Using yeast surface display of DIII variants, we defined contact residues of a panel of type-specific, subcomplex-specific, and cross-reactive MAbs that recognize DIII of DENV type 2 (DENV-2) and have different neutralizing potentials. Type-specific MAbs with neutralizing activity against DENV-2 localized to a sequence-unique epitope on the lateral ridge of DIII, centered at the FG loop near residues E383 and P384, analogous in position to that observed with WNV-specific strongly neutralizing MAbs. Subcomplex-specific MAbs that bound some but not all DENV serotypes and neutralized DENV-2 infection recognized an adjacent epitope centered on the connecting A strand of DIII at residues K305, K307, and K310. In contrast, several MAbs that had poor neutralizing activity against DENV-2 and cross-reacted with all DENV serotypes and other flaviviruses recognized an epitope with residues in the AB loop of DIII, a conserved region that is predicted to have limited accessibility on the mature virion. Overall, our experiments define adjacent and structurally distinct epitopes on DIII of DENV-2 which elicit type-specific, subcomplex-specific, and cross-reactive antibodies with different neutralizing potentials.
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Affiliation(s)
- Soila Sukupolvi-Petty
- Department of Medicine, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
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265
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Gai SA, Wittrup KD. Yeast surface display for protein engineering and characterization. Curr Opin Struct Biol 2007; 17:467-73. [PMID: 17870469 PMCID: PMC4038029 DOI: 10.1016/j.sbi.2007.08.012] [Citation(s) in RCA: 270] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/03/2007] [Accepted: 08/19/2007] [Indexed: 11/23/2022]
Abstract
Yeast surface display is being employed to engineer desirable properties into proteins for a broad variety of applications. Labeling with soluble ligands enables rapid and quantitative analysis of yeast-displayed libraries by flow cytometry, while cell-surface selections allow screening of libraries with insoluble or even as-yet-uncharacterized binding targets. In parallel, the utilization of yeast surface display for protein characterization, including in particular the mapping of functional epitopes mediating protein–protein interactions, represents a significant recent advance.
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Affiliation(s)
- S Annie Gai
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room E19-563, Cambridge, MA 02139, USA
| | - K Dane Wittrup
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room E19-563, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room E19-563, Cambridge, MA 02139, USA
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266
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Lisova O, Hardy F, Petit V, Bedouelle H. Mapping to completeness and transplantation of a group-specific, discontinuous, neutralizing epitope in the envelope protein of dengue virus. J Gen Virol 2007; 88:2387-2397. [PMID: 17698647 DOI: 10.1099/vir.0.83028-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dengue is caused by a taxonomic group of four viruses, dengue virus types 1–4 (DENV1–DENV4). A molecular understanding of the antibody-mediated protection against this disease is critical to design safe vaccines and therapeutics. Here, the energetic epitope of antibody mAb4E11, which neutralizes the four serotypes of DENV but no other flavivirus, and binds domain 3 (ED3) of their envelope glycoprotein, was characterized. Alanine-scanning mutagenesis of the ED3 domain from serotype DENV1 was performed and the affinities between the mutant domains and the Fab fragment of mAb4E11 were measured. The epitope residues (307–312, 387, 389 and 391) were at the edges of two distinct β-sheets. Four residues constituted hot spots of binding energy. They were aliphatic and contributed to form a hydrophobic pocket (Leu308, Leu389), or were positively charged (Lys307, Lys310). They may bind the diversity residues of mAb4E11, H-Trp96-Glu97. Remarkably, cyclic residues occupy and block the hydrophobic pocket in all unrelated flaviviruses. Transplanting the epitope from the ED3 domain of DENV into those of other flaviviruses restored affinity. The epitope straddles residues of ED3 that are involved in virulence, e.g. Asn/Asp390. These results define the epitope of mAb4E11 as an antigenic signature of the DENV group and suggest mechanisms for its neutralization potency.
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Affiliation(s)
- Olesia Lisova
- Unit of Molecular Prevention and Therapy of Human Diseases (CNRS-URA3012), Institut Pasteur, 28 rue Docteur Roux, F-75724 Paris Cedex 15, France
| | - Florence Hardy
- Unit of Molecular Prevention and Therapy of Human Diseases (CNRS-URA3012), Institut Pasteur, 28 rue Docteur Roux, F-75724 Paris Cedex 15, France
| | - Vincent Petit
- Unit of Molecular Prevention and Therapy of Human Diseases (CNRS-URA3012), Institut Pasteur, 28 rue Docteur Roux, F-75724 Paris Cedex 15, France
| | - Hugues Bedouelle
- Unit of Molecular Prevention and Therapy of Human Diseases (CNRS-URA3012), Institut Pasteur, 28 rue Docteur Roux, F-75724 Paris Cedex 15, France
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267
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Gromowski GD, Barrett ADT. Characterization of an antigenic site that contains a dominant, type-specific neutralization determinant on the envelope protein domain III (ED3) of dengue 2 virus. Virology 2007; 366:349-60. [PMID: 17719070 DOI: 10.1016/j.virol.2007.05.042] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 03/22/2007] [Accepted: 05/22/2007] [Indexed: 11/27/2022]
Abstract
The surface of the mature dengue virus (DENV) particle consists of 90 envelope (E) protein dimers that mediate both receptor binding and fusion. The E protein ectodomain can be divided into three structural domains designated ED1, ED2, and ED3, of which ED3 contains the critical and dominant virus-specific neutralization sites. In this study the ED3 epitopes recognized by seven, murine, IgG1 DENV-2 type-specific, monoclonal antibodies (MAbs) were determined using site-directed mutagenesis of a recombinant DENV-2 ED3 (rED3) protein. A total of 41 single amino acid substitutions were introduced into the rED3 at 30 different surface accessible residues. The affinity of each MAb with the mutant rED3s was assessed by indirect ELISA and the results indicate that all seven MAbs recognize overlapping epitopes with residues K305 and P384 critical for binding. These residues are conserved among DENV-2 strains and cluster together on the upper lateral face of ED3. A linear relationship was observed between relative occupancy of ED3 on the virion by MAb and neutralization of the majority of virus infectivity ( approximately 90%) for all seven MAbs. Depending on the MAb, it is predicted that between 10% and 50% relative occupancy of ED3 on the virion is necessary for virus neutralization and for all seven MAbs occupancy levels approaching saturation were required for 100% neutralization of virus infectivity. Overall, the conserved antigenic site recognized by all seven MAbs is likely to be a dominant DENV-2 type-specific, neutralization determinant.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution/genetics
- Amino Acid Substitution/immunology
- Antibodies, Monoclonal/immunology
- Antibodies, Viral/immunology
- Antibody Affinity
- Antigens, Viral/chemistry
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Dengue Virus/immunology
- Enzyme-Linked Immunosorbent Assay
- Epitope Mapping
- Epitopes, B-Lymphocyte/genetics
- Epitopes, B-Lymphocyte/immunology
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/immunology
- Immunoglobulin G/immunology
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Neutralization Tests
- Protein Structure, Tertiary/genetics
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- Gregory D Gromowski
- Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555-0609, USA
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268
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Noueiry AO, Olivo PD, Slomczynska U, Zhou Y, Buscher B, Geiss B, Engle M, Roth RM, Chung KM, Samuel M, Diamond MS. Identification of novel small-molecule inhibitors of West Nile virus infection. J Virol 2007; 81:11992-2004. [PMID: 17715228 PMCID: PMC2168801 DOI: 10.1128/jvi.01358-07] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
West Nile virus (WNV) has spread throughout the United States and Canada and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to acute flaccid paralysis and lethal encephalitis. No therapy or vaccine is currently approved for use in humans. Using high-throughput screening assays that included a luciferase expressing WNV subgenomic replicon and an NS1 capture enzyme-linked immunosorbent assay, we evaluated a chemical library of over 80,000 compounds for their capacity to inhibit WNV replication. We identified 10 compounds with strong inhibitory activity against genetically diverse WNV and Kunjin virus isolates. Many of the inhibitory compounds belonged to a chemical family of secondary sulfonamides and have not been described previously to inhibit WNV or other related or unrelated viruses. Several of these compounds inhibited WNV infection in the submicromolar range, had selectivity indices of greater than 10, and inhibited replication of other flaviviruses, including dengue and yellow fever viruses. One of the most promising compounds, AP30451, specifically blocked translation of a yellow fever virus replicon but not a Sindbis virus replicon or an internal ribosome entry site containing mRNA. Overall, these compounds comprise a novel class of promising inhibitors for therapy against WNV and other flavivirus infections in humans.
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269
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Oliphant T, Nybakken GE, Austin SK, Xu Q, Bramson J, Loeb M, Throsby M, Fremont DH, Pierson TC, Diamond MS. Induction of epitope-specific neutralizing antibodies against West Nile virus. J Virol 2007; 81:11828-39. [PMID: 17715236 PMCID: PMC2168772 DOI: 10.1128/jvi.00643-07] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Previous studies have established that an epitope on the lateral ridge of domain III (DIII-lr) of West Nile virus (WNV) envelope (E) protein is recognized by strongly neutralizing type-specific antibodies. In contrast, an epitope against the fusion loop in domain II (DII-fl) is recognized by flavivirus cross-reactive antibodies with less neutralizing potential. Using gain- and loss-of-function E proteins and wild-type and variant WNV reporter virus particles, we evaluated the expression pattern and activity of antibodies against the DIII-lr and DII-fl epitopes in mouse and human serum after WNV infection. In mice, immunoglobulin M (IgM) antibodies to the DIII-lr epitope were detected at low levels at day 6 after infection. However, compared to IgG responses against other epitopes in DI and DII, which were readily detected at day 8, the development of IgG against DIII-lr epitope was delayed and did not appear consistently until day 15. This late time point is notable since almost all death after WNV infection in mice occurs by day 12. Nonetheless, at later time points, DIII-lr antibodies accumulated and comprised a significant fraction of the DIII-specific IgG response. In sera from infected humans, DIII-lr antibodies were detected at low levels and did not correlate with clinical outcome. In contrast, antibodies to the DII-fl were detected in all human serum samples and encompassed a significant percentage of the anti-E protein response. Our experiments suggest that the highly neutralizing DIII-lr IgG antibodies have little significant role in primary infection and that the antibody response of humans may be skewed toward the induction of cross-reactive, less-neutralizing antibodies.
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Affiliation(s)
- Theodore Oliphant
- Departments of Medicine, Molecular Microbiology, and Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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270
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Stiasny K, Brandler S, Kössl C, Heinz FX. Probing the flavivirus membrane fusion mechanism by using monoclonal antibodies. J Virol 2007; 81:11526-31. [PMID: 17670824 PMCID: PMC2045551 DOI: 10.1128/jvi.01041-07] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we investigated in a flavivirus model (tick-borne encephalitis virus) the mechanisms of fusion inhibition by monoclonal antibodies directed to the different domains of the fusion protein (E) and to different sites within each of the domains by using in vitro fusion assays. Our data indicate that, depending on the location of their binding sites, the monoclonal antibodies impaired early or late stages of the fusion process, by blocking the initial interaction with the target membrane or by interfering with the proper formation of the postfusion structure of E, respectively. These data provide new insights into the mechanisms of flavivirus fusion inhibition by antibodies and their possible contribution to virus neutralization.
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Affiliation(s)
- Karin Stiasny
- Institute of Virology, Medical University of Vienna, Kinderspitalgasse 15, AT-1095, Vienna, Austria.
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271
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Oliphant T, Diamond MS. The molecular basis of antibody-mediated neutralization of West Nile virus. Expert Opin Biol Ther 2007; 7:885-92. [PMID: 17555373 DOI: 10.1517/14712598.7.6.885] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The study of the interaction between the West Nile virus envelope protein and monoclonal antibodies has provided insight into the molecular mechanisms of neutralization. Structural studies have identified an epitope on the lateral ridge of domain III of the West Nile virus E protein that is recognized by antibodies with the strongest neutralizing activity in vitro and in vivo. Antibodies that bind to this epitope are particularly inhibitory because they block infection at a post-attachment step and at concentrations that result in a low occupancy of the available sites on the virion.
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Affiliation(s)
- Theodore Oliphant
- Washington University School of Medicine, Department of Molecular Microbiology, Saint Louis, MO 63110, USA
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272
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Campbell JA, Trossman DS, Yokoyama WM, Carayannopoulos LN. Zoonotic orthopoxviruses encode a high-affinity antagonist of NKG2D. ACTA ACUST UNITED AC 2007; 204:1311-7. [PMID: 17548517 PMCID: PMC2118624 DOI: 10.1084/jem.20062026] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
NK and T lymphocytes express both activating and inhibiting receptors for various members of the major histocompatibility complex class I superfamily (MHCISF). To evade immunologic cytotoxicity, many viruses interfere with the function of these receptors, generally by altering the displayed profile of MHCISF proteins on host cells. Using a structurally constrained hidden Markov model, we discovered an orthopoxvirus protein, itself distantly class I-like, that acts as a competitive antagonist of the NKG2D activating receptor. This orthopoxvirus MHC class I-like protein (OMCP) is conserved among cowpox and monkeypox viruses, secreted by infected cells, and bound with high affinity by NKG2D of rodents and humans (K(D) approximately 30 and 0.2 nM, respectively). OMCP blocks recognition of host-encoded ligands and inhibits NKG2D-dependent killing by NK cells. This finding represents a novel mechanism for viral interference with NKG2D and sheds light on intercellular recognition events underlying innate immunity against emerging orthopoxviruses.
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Affiliation(s)
- Jessica A Campbell
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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273
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Herrmann S, Leshem B, Lobel L, Bin H, Mendelson E, Ben-Nathan D, Dussart P, Porgador A, Rager-Zisman B, Marks RS. T7 phage display of Ep15 peptide for the detection of WNV IgG. J Virol Methods 2007; 141:133-40. [PMID: 17215048 DOI: 10.1016/j.jviromet.2006.11.041] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 11/20/2006] [Accepted: 11/27/2006] [Indexed: 11/21/2022]
Abstract
West Nile virus (WNV) is one of the major emerging infectious diseases in North America. WNV belongs to the genus Flavivirus, and its rapid and extensive global spread has highlighted the necessity for accurate and specific assays for diagnosis of WNV infection. This study presents the first phage displayed peptide based ELISA for detection of WNV immunoglobulin G (IgG). The Ep15 epitope, derived from the WNV E protein DIII, was cloned into a T7 phage display system that was then used as recombinant antigen in a chemiluminescent ELISA format. The phage concentration was optimized at 5 x 10(10)PFU/ml and was used directly after polyethylene glycol concentration. The assay shows a limit of detection at a serum titer of 1:51,200 and a dynamic range from 1:100 to 1:2000. A screen of a panel of 66 human sera samples, and comparison with a commercial kit, revealed a sensitivity of 67% and a specificity of 100%. Considering the ease of antigen preparation, its stability and the optimum display properties of the T7 bacteriophage, it is apparent that this approach can be useful for the preparation of highly sensitive and specific anti-WNV immunoglobulin diagnostic kits.
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Affiliation(s)
- Sebastien Herrmann
- Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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274
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Morrey JD, Siddharthan V, Olsen AL, Wang H, Julander JG, Hall JO, Li H, Nordstrom JL, Koenig S, Johnson S, Diamond MS. Defining limits of treatment with humanized neutralizing monoclonal antibody for West Nile virus neurological infection in a hamster model. Antimicrob Agents Chemother 2007; 51:2396-402. [PMID: 17452485 PMCID: PMC1913249 DOI: 10.1128/aac.00147-07] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A potent anti-West Nile virus (anti-WNV)-neutralizing humanized monoclonal antibody, hE16, was previously shown to improve the survival of WNV-infected hamsters when it was administered intraperitoneally (i.p.), even after the virus had infected neurons in the brain. In this study, we evaluated the therapeutic limit of hE16 for the treatment of WNV infection in hamsters by comparing single-dose peripheral (i.p.) therapy with direct administration into the pons through a convection-enhanced delivery (CED) system. At day 5 after infection, treatments with hE16 by the peripheral and the CED routes were equally effective at reducing morbidity and mortality. In contrast, at day 6 only the treatment by the CED route protected the hamsters from lethal infection. These experiments suggest that hE16 can directly control WNV infection in the central nervous system. In support of this, hE16 administered i.p. was detected in a time-dependent manner in the serum, cerebrospinal fluid (CSF), cerebral cortex, brain stem, and spinal cord in CSF. A linear relationship between the hE16 dose and the concentration in serum was observed, and maximal therapeutic activity occurred at doses of 0.32 mg/kg of body weight or higher, which produced serum hE16 concentrations of 1.3 microg/ml or higher. Overall, these data suggest that in hamsters hE16 can ameliorate neurological disease after significant viral replication has occurred, although there is a time window that limits therapeutic efficacy.
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Affiliation(s)
- John D Morrey
- Institute for Antiviral Research, Animal, Dairy, and Veterinary Sciences Department, Utah State University, 4700 Old Main Hill, Logan, UT 84322-4700, USA.
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275
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Hong WWL, Yen YH, Wu SC. Enhanced antibody affinity to Japanese encephalitis virus E protein by phage display. Biochem Biophys Res Commun 2007; 356:124-8. [PMID: 17350601 DOI: 10.1016/j.bbrc.2007.02.117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 02/20/2007] [Indexed: 10/23/2022]
Abstract
Obtaining antibodies with high affinity and specificity against antigens are required for the development of therapeutic and diagnostic antibodies. In this study, the contributions to binding affinity in the CDR2 and CDR3 regions of two monoclonal antibodies E3.3 and 2H2 were investigated by random mutagenesis in a phage-display synthetic oligonucleotide library. One high-affinity clone (CDR3-30) was obtained with a 3-fold increase of the dissociation constant, resulting from the changes in amino acids at residues 95, 97, and 98 in the CDRH3 region. Analysis of the predicted structure by modeling suggested that the contributions of mutated residues in the CDR3 region to the binding affinity involved not only complementarity between antigen and CDR3, but also interaction between heavy and light chains. The information gained from this study may benefit the design of vaccines and therapeutic antibodies against Japanese encephalitis virus infection.
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Affiliation(s)
- Willy W L Hong
- Institute of Biotechnology, Department of Life Science, National Tsing-Hua University, Hsinchu 30013, Taiwan
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276
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Volk DE, Lee YC, Li X, Thiviyanathan V, Gromowski GD, Li L, R.Lamb A, Beasley DWC, Barrett ADT, Gorenstein DG. Solution structure of the envelope protein domain III of dengue-4 virus. Virology 2007; 364:147-54. [PMID: 17395234 PMCID: PMC1950219 DOI: 10.1016/j.virol.2007.02.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 01/09/2007] [Accepted: 02/07/2007] [Indexed: 11/15/2022]
Abstract
The disease dengue (DEN) is caused by four serologically related viruses termed DEN1, DEN2, DEN3 and DEN4. The structure of the ectodomain of the envelope protein has been determined previously for DEN2 and DEN3 viruses. Using NMR spectroscopic methods, we solved the solution structure of domain III (ED3), the receptor-binding domain, of the envelope protein of DEN4 virus, human strain 703-4. The structure shows that the nine amino acid changes in ED3 that separate the sylvatic and human DEN4 strains are surface exposed. Important structural differences between DEN4-rED3 and ED3 domains of DEN2, DEN3 and other flaviviruses are discussed.
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Affiliation(s)
- David E. Volk
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Yi-Chien Lee
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Xin Li
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Varatharasa Thiviyanathan
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Gregory D. Gromowski
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1157
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-1157
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555-1157
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Li Li
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1157
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-1157
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555-1157
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Ashley R.Lamb
- School of Natural Sciences, University of Texas at Austin, Austin, TX
| | - David W. C. Beasley
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555-1157
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-1157
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555-1157
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - Alan D. T. Barrett
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1157
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-1157
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555-1157
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555-1157
| | - David G. Gorenstein
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1157
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555-1157
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277
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Chu JHJ, Chiang CCS, Ng ML. Immunization of Flavivirus West Nile Recombinant Envelope Domain III Protein Induced Specific Immune Response and Protection against West Nile Virus Infection. THE JOURNAL OF IMMUNOLOGY 2007; 178:2699-705. [PMID: 17312111 DOI: 10.4049/jimmunol.178.5.2699] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The domain III of the West Nile virus (WNV) envelope glycoprotein (E) was shown to serve as virus attachment domain to the cellular receptor, and neutralizing Abs have been mapped to this specific domain. In this study, domain III of the WNV E protein (WNV E DIII) was expressed as a recombinant protein and its potential as a subunit vaccine candidate was evaluated in BALB/C mice. Immunization of WNV E DIII protein with oligodeoxynucleotides (CpG-DNA) adjuvant by i.p. injection was conducted over a period of 3 wk. The immunized mice generated high titer of WNV-neutralizing Abs. Murine Ab against WNV E DIII protein was also capable of neutralizing Japanese encephalitis virus. The IgG isotypes generated were predominantly IgG2a in the murine sera against the recombinant protein. Splenocyte cultures from the mice coadministrated with WNV E DIII protein and CpG secreted large amounts of IFN-gamma and IL-2 and showed proliferation of T cells in the presence of WNV E DIII protein. Overall, this study highlighted that recombinant WNV E DIII protein delivered in combination with CpG adjuvant to mice generated a Th1 immune response type against WNV and can serve as a potential vaccine to prevent WNV infection.
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Affiliation(s)
- Jang-Hann J Chu
- Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597
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278
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Choi KS, Nah JJ, Ko YJ, Kim YJ, Joo YS. The DE loop of the domain III of the envelope protein appears to be associated with West Nile virus neutralization. Virus Res 2007; 123:216-8. [PMID: 17027114 DOI: 10.1016/j.virusres.2006.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 08/31/2006] [Accepted: 09/01/2006] [Indexed: 11/16/2022]
Abstract
The envelope (E) protein of WNV plays an important role in the virus neutralization. Using a mAb 5E8, a neutralizing epitope on the domain III of the E of the New York strain of WN virus was characterized. Results from neutralization-escape mutants and site-directed mutagenesis revealed that the 5E8 epitope is a highly conformation dependent epitope consisting of at least residues E330, E332 and E367 on the domain III. Besides known critical neutralizing epitopes E330 and E332, our results indicate that residue E367, a component of DE loop on the domain III, appeared to be associated with neutralization but little with neuroinvasion of the virus, as reported previously (Beasley et al., 2002).
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Affiliation(s)
- Kang-Seuk Choi
- Foreign Animal Disease Division, National Veterinary Research and Quarantine Service, 480 Anyang-6 Dong, Anyang, Gyeonggi 430-824, Republic of Korea.
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279
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Nelson CD, Palermo LS, Hafenstein SL, Parrish CR. Different mechanisms of antibody-mediated neutralization of parvoviruses revealed using the Fab fragments of monoclonal antibodies. Virology 2007; 361:283-93. [PMID: 17217977 PMCID: PMC1991280 DOI: 10.1016/j.virol.2006.11.032] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 10/25/2006] [Accepted: 11/29/2006] [Indexed: 11/20/2022]
Abstract
Antibody binding and neutralization are major host defenses against viruses, yet the mechanisms are often not well understood. Eight monoclonal antibodies and their Fab fragments were tested for neutralization of canine parvovirus and feline panleukopenia virus. All IgGs neutralized >85% of virus infectivity. Two Fabs neutralized when present at 5 nM, while the others gave little or no neutralization even at 20-100 nM. The antibodies bind two antigenic sites on the capsids which overlap the binding site of the host transferrin receptor (TfR). There was no specific correlation between Fab binding affinity and neutralization. All Fabs reduced capsid binding of virus to purified feline TfR in vitro, but the highly neutralizing Fabs were more efficient competitors. All partially prevented binding and uptake of capsids by feline TfR on cells. The virus appears adapted to allow some infectivity in the presence of at least low levels of antibodies.
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Affiliation(s)
- Christian D.S. Nelson
- Baker Institute for Animal Health, and Department of Microbiology and Immunology, Collegeof Veterinary Medicine, Cornell University, Ithaca, NY 14853 USA
| | - Laura S. Palermo
- Baker Institute for Animal Health, and Department of Microbiology and Immunology, Collegeof Veterinary Medicine, Cornell University, Ithaca, NY 14853 USA
| | - Susan L. Hafenstein
- Department of Biological Sciences, Lilley Hall, Purdue University, West Lafayette, IN 47907-1392 USA
| | - Colin R. Parrish
- Baker Institute for Animal Health, and Department of Microbiology and Immunology, Collegeof Veterinary Medicine, Cornell University, Ithaca, NY 14853 USA
- *Corresponding author: Colin R. Parrish, Baker Institute for Animal Health, and Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 USA Telephone: (607) 256-5649 Fax: (607) 256-5608
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280
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King NJC, Getts DR, Getts MT, Rana S, Shrestha B, Kesson AM. Immunopathology of flavivirus infections. Immunol Cell Biol 2006; 85:33-42. [PMID: 17146465 DOI: 10.1038/sj.icb.7100012] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
With the recent emergence of the flavivirus, West Nile virus (WNV), in particular, the New York strain of Lineage I WNV in North America in 1999, there has been a significant increase in activity in neurotropic flavivirus research. These viruses cause encephalitis that can result in permanent neurological sequelae or death. Attempts to develop vaccines have made progress, but have been variably successful, despite considerable commercial underwriting. Thus, the discovery of ways and means to combat disease is no less urgent. As such, most recent work has been directed towards dissecting and understanding the pathogenesis of disease, as a way of informing possible approaches to abrogation or amelioration of illness. Whether inherent to flaviviruses or because humans are incidental, dead-end hosts, it is clear that these viruses interact with their human hosts in extremely complex ways. This occurs from the cellular level, at which infection must be established to produce disease, to its interaction with the adaptive immune response, which may result in its eradication, with or without immunopathological and consequent neurological sequelae. As human proximity to and contact with flavivirus insect vectors and amplifying hosts cannot practically be eliminated, our understanding of the pathogenesis of flavivirus-induced diseases, especially with regard to possible targets for treatment, is imperative.
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Affiliation(s)
- Nicholas J C King
- Department of Pathology, School of Medical Sciences, Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia.
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281
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Davis LE, DeBiasi R, Goade DE, Haaland KY, Harrington JA, Harnar JB, Pergam SA, King MK, DeMasters BK, Tyler KL. West Nile virus neuroinvasive disease. Ann Neurol 2006; 60:286-300. [PMID: 16983682 DOI: 10.1002/ana.20959] [Citation(s) in RCA: 222] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Since 1999, there have been nearly 20,000 cases of confirmed symptomatic West Nile virus (WNV) infection in the United States, and it is likely that more than 1 million people have been infected by the virus. WNV is now the most common cause of epidemic viral encephalitis in the United States, and it will likely remain an important cause of neurological disease for the foreseeable future. Clinical syndromes produced by WNV infection include asymptomatic infection, West Nile Fever, and West Nile neuroinvasive disease (WNND). WNND includes syndromes of meningitis, encephalitis, and acute flaccid paralysis/poliomyelitis. The clinical, laboratory, and diagnostic features of these syndromes are reviewed here. Many patients with WNND have normal neuroimaging studies, but abnormalities may be present in areas including the basal ganglia, thalamus, cerebellum, and brainstem. Cerebrospinal fluid invariably shows a pleocytosis, with a predominance of neutrophils in up to half the patients. Diagnosis of WNND depends predominantly on demonstration of WNV-specific IgM antibodies in cerebrospinal fluid. Recent studies suggest that some WNV-infected patients have persistent WNV IgM serum and/or cerebrospinal fluid antibody responses, and this may require revision of current serodiagnostic criteria. Although there is no proven therapy for WNND, several vaccines and antiviral therapy with antibodies, antisense oligonucleotides, and interferon preparations are currently undergoing human clinical trials. Recovery from neurological sequelae of WNV infection including cognitive deficits and weakness may be prolonged and incomplete.
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Affiliation(s)
- Larry E Davis
- Neurology Services, New Mexico Veterans Affairs Health Care System, University of New Mexico, Albuquerque, NM, USA
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282
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Stiasny K, Kiermayr S, Holzmann H, Heinz FX. Cryptic properties of a cluster of dominant flavivirus cross-reactive antigenic sites. J Virol 2006; 80:9557-68. [PMID: 16973559 PMCID: PMC1617264 DOI: 10.1128/jvi.00080-06] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A number of flaviviruses are important human pathogens, including yellow fever, dengue, West Nile, Japanese encephalitis, and tick-borne encephalitis (TBE) viruses. Infection with or immunization against any of these viruses induces a subset of antibodies that are broadly flavivirus cross-reactive but do not exhibit significant cross-neutralization. Nevertheless, these antibodies can efficiently bind to the major envelope protein (E), which is the main target of neutralizing and protective antibodies because of its receptor-binding and membrane fusion functions. The structural basis for this phenomenon is still unclear. In our studies with TBE virus, we have provided evidence that such cross-reactive antibodies are specific for a cluster of epitopes that are partially occluded in the cage-like assembly of E proteins at the surfaces of infectious virions and involve-but are not restricted to-amino acids of the highly conserved internal fusion peptide loop. Virus disintegration leads to increased accessibility of these epitopes, allowing the cross-reactive antibodies to bind with strongly increased avidity. The cryptic properties of these sites in the context of infectious virions can thus provide an explanation for the observed lack of efficient neutralizing activity of broadly cross-reactive antibodies, despite their specificity for a functionally important structural element in the E protein.
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Affiliation(s)
- Karin Stiasny
- Institute of Virology, Medical University of Vienna, Kinderspitalgasse 15, A-1095 Vienna, Austria
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283
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Samuel MA, Diamond MS. Pathogenesis of West Nile Virus infection: a balance between virulence, innate and adaptive immunity, and viral evasion. J Virol 2006; 80:9349-60. [PMID: 16973541 PMCID: PMC1617273 DOI: 10.1128/jvi.01122-06] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Melanie A Samuel
- Division of Infectious Diseases, Department of Molecular Microbiology, Washington University School of Medicine, Campus Box 8051, 660 S. Euclid Ave., St. Louis, MO 63110, USA
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284
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Sánchez MD, Pierson TC, Degrace MM, Mattei LM, Hanna SL, Del Piero F, Doms RW. The neutralizing antibody response against West Nile virus in naturally infected horses. Virology 2006; 359:336-48. [PMID: 17055550 DOI: 10.1016/j.virol.2006.08.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 07/21/2006] [Accepted: 08/29/2006] [Indexed: 11/22/2022]
Abstract
A major neutralizing epitope (here referred to as the T332 epitope) located on the lateral surface of domain III (DIII) of the West Nile virus (WNV) envelope protein has been identified based on the analysis of murine monoclonal antibodies. However, little is known about the humoral immune response against WNV in a natural host or whether DIII in general or the T332 epitope in particular are important targets of neutralizing antibodies in vivo. To characterize the types of antibodies produced during infection with WNV, we studied a group of naturally infected horses. Using immune adsorption assays coupled with the use of virus particles bearing mutations in the T332 epitope, we found that in some animals neutralizing activity against DIII and the T332 epitope was below the limit of detection. In contrast, some animals generated a significant fraction of neutralizing activity to DIII and the T332 epitope. Thus, while antibodies to the T332 epitope did not represent a significant fraction of the total antibody response in the infected animals studied, in some horses, they comprised a significant fraction of neutralizing activity, making this an important but far from dominant neutralizing epitope. Rather, the neutralizing response to WNV generated in infected horses is both variable and polyclonal in nature, with epitopes within and outside of DIII playing important roles.
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Affiliation(s)
- Melissa D Sánchez
- Department of Microbiology, University of Pennsylvania, 225 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
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285
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Oliphant T, Nybakken GE, Engle M, Xu Q, Nelson CA, Sukupolvi-Petty S, Marri A, Lachmi BE, Olshevsky U, Fremont DH, Pierson TC, Diamond MS. Antibody recognition and neutralization determinants on domains I and II of West Nile Virus envelope protein. J Virol 2006; 80:12149-59. [PMID: 17035317 PMCID: PMC1676294 DOI: 10.1128/jvi.01732-06] [Citation(s) in RCA: 248] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies have demonstrated that monoclonal antibodies (MAbs) against an epitope on the lateral surface of domain III (DIII) of the West Nile virus (WNV) envelope (E) strongly protect against infection in animals. Herein, we observed significantly less efficient neutralization by 89 MAbs that recognized domain I (DI) or II (DII) of WNV E protein. Moreover, in cells expressing Fc gamma receptors, many of the DI- and DII-specific MAbs enhanced infection over a broad range of concentrations. Using yeast surface display of E protein variants, we identified 25 E protein residues to be critical for recognition by DI- or DII-specific neutralizing MAbs. These residues cluster into six novel and one previously characterized epitope located on the lateral ridge of DI, the linker region between DI and DIII, the hinge interface between DI and DII, and the lateral ridge, central interface, dimer interface, and fusion loop of DII. Approximately 45% of DI-DII-specific MAbs showed reduced binding with mutations in the highly conserved fusion loop in DII: 85% of these (34 of 40) cross-reacted with the distantly related dengue virus (DENV). In contrast, MAbs that bound the other neutralizing epitopes in DI and DII showed no apparent cross-reactivity with DENV E protein. Surprisingly, several of the neutralizing epitopes were located in solvent-inaccessible positions in the context of the available pseudoatomic model of WNV. Nonetheless, DI and DII MAbs protect against WNV infection in mice, albeit with lower efficiency than DIII-specific neutralizing MAbs.
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Affiliation(s)
- Theodore Oliphant
- Department of Medicine, Washington University School of Medicine, 660 South Euclid Ave., Box 8051, Saint Louis, MO 63110, USA
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286
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Debiasi RL, Tyler KL. West Nile virus meningoencephalitis. ACTA ACUST UNITED AC 2006; 2:264-75. [PMID: 16932563 PMCID: PMC3773989 DOI: 10.1038/ncpneuro0176] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 03/07/2006] [Indexed: 01/10/2023]
Abstract
Since its first appearance in the US in 1999, West Nile virus (WNV) has emerged as the most common cause of epidemic meningoencephalitis in North America. In the 6 years following the 1999 outbreak, the geographic range and burden of the disease in birds, mosquitoes and humans has greatly expanded to include the 48 contiguous US and 7 Canadian provinces, as well as Mexico, the Caribbean islands and Colombia. WNV has shown an increasing propensity for neuroinvasive disease over the past decade, with varied presentations including meningitis, encephalitis and acute flaccid paralysis. Although neuroinvasive disease occurs in less than 1% of infected individuals, it is associated with high mortality. From 1999-2005, more than 8,000 cases of neuroinvasive WNV disease were reported in the US, resulting in over 780 deaths. In this review, we discuss epidemiology, risk factors, clinical features, diagnosis and prognosis of WNV meningoencephalitis, along with potential treatments.
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Affiliation(s)
- Roberta L Debiasi
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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287
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Nybakken GE, Nelson CA, Chen BR, Diamond MS, Fremont DH. Crystal structure of the West Nile virus envelope glycoprotein. J Virol 2006; 80:11467-74. [PMID: 16987985 PMCID: PMC1642602 DOI: 10.1128/jvi.01125-06] [Citation(s) in RCA: 202] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The envelope glycoprotein (E) of West Nile virus (WNV) undergoes a conformational rearrangement triggered by low pH that results in a class II fusion event required for viral entry. Herein we present the 3.0-A crystal structure of the ectodomain of WNV E, which reveals insights into the flavivirus life cycle. We found that WNV E adopts a three-domain architecture that is shared by the E proteins from dengue and tick-borne encephalitis viruses and forms a rod-shaped configuration similar to that observed in immature flavivirus particles. Interestingly, the single N-linked glycosylation site on WNV E is displaced by a novel alpha-helix, which could potentially alter lectin-mediated attachment. The localization of histidines within the hinge regions of E implicates these residues in pH-induced conformational transitions. Most strikingly, the WNV E ectodomain crystallized as a monomer, in contrast to other flavivirus E proteins, which have crystallized as antiparallel dimers. WNV E assembles in a crystalline lattice of perpendicular molecules, with the fusion loop of one E protein buried in a hydrophobic pocket at the DI-DIII interface of another. Dimeric E proteins pack their fusion loops into analogous pockets at the dimer interface. We speculate that E proteins could pivot around the fusion loop-pocket junction, allowing virion conformational transitions while minimizing fusion loop exposure.
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Affiliation(s)
- Grant E Nybakken
- Department of Pathology & Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Avenue, St. Louis, MO 63110-1093, USA
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288
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Kanai R, Kar K, Anthony K, Gould LH, Ledizet M, Fikrig E, Marasco WA, Koski RA, Modis Y. Crystal structure of west nile virus envelope glycoprotein reveals viral surface epitopes. J Virol 2006; 80:11000-8. [PMID: 16943291 PMCID: PMC1642136 DOI: 10.1128/jvi.01735-06] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
West Nile virus, a member of the Flavivirus genus, causes fever that can progress to life-threatening encephalitis. The major envelope glycoprotein, E, of these viruses mediates viral attachment and entry by membrane fusion. We have determined the crystal structure of a soluble fragment of West Nile virus E. The structure adopts the same overall fold as that of the E proteins from dengue and tick-borne encephalitis viruses. The conformation of domain II is different from that in other prefusion E structures, however, and resembles the conformation of domain II in postfusion E structures. The epitopes of neutralizing West Nile virus-specific antibodies map to a region of domain III that is exposed on the viral surface and has been implicated in receptor binding. In contrast, we show that certain recombinant therapeutic antibodies, which cross-neutralize West Nile and dengue viruses, bind a peptide from domain I that is exposed only during the membrane fusion transition. By revealing the details of the molecular landscape of the West Nile virus surface, our structure will assist the design of antiviral vaccines and therapeutics.
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Affiliation(s)
- Ryuta Kanai
- 266Department of Molecular Biophysics and Biochemistry, The Bass Center for Structural Biology, Yale University, 266 Whitney Ave., New Haven, Connecticut 06520, USA
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289
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Throsby M, Geuijen C, Goudsmit J, Bakker AQ, Korimbocus J, Kramer RA, Clijsters-van der Horst M, de Jong M, Jongeneelen M, Thijsse S, Smit R, Visser TJ, Bijl N, Marissen WE, Loeb M, Kelvin DJ, Preiser W, ter Meulen J, de Kruif J. Isolation and characterization of human monoclonal antibodies from individuals infected with West Nile Virus. J Virol 2006; 80:6982-92. [PMID: 16809304 PMCID: PMC1489037 DOI: 10.1128/jvi.00551-06] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Monoclonal antibodies (MAbs) neutralizing West Nile Virus (WNV) have been shown to protect against infection in animal models and have been identified as a correlate of protection in WNV vaccine studies. In the present study, antibody repertoires from three convalescent WNV-infected patients were cloned into an scFv phage library, and 138 human MAbs binding to WNV were identified. One hundred twenty-one MAbs specifically bound to the viral envelope (E) protein and four MAbs to the premembrane (prM) protein. Enzyme-linked immunosorbent assay-based competitive-binding assays with representative E protein-specific MAbs demonstrated that 24/51 (47%) bound to domain II while only 4/51 (8%) targeted domain III. In vitro neutralizing activity was demonstrated for 12 MAbs, and two of these, CR4374 and CR4353, protected mice from lethal WNV challenge at 50% protective doses of 12.9 and 357 mug/kg of body weight, respectively. Our data analyzing three infected individuals suggest that the human anti-WNV repertoire after natural infection is dominated by nonneutralizing or weakly neutralizing MAbs binding to domain II of the E protein, while domain III-binding MAbs able to potently neutralize WNV in vitro and in vivo are rare.
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Affiliation(s)
- Mark Throsby
- Crucell Holland B.V., P.O. Box 2048, 2301 CA, Leiden, The Netherlands.
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290
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Kaufmann B, Nybakken GE, Chipman PR, Zhang W, Diamond MS, Fremont DH, Kuhn RJ, Rossmann MG. West Nile virus in complex with the Fab fragment of a neutralizing monoclonal antibody. Proc Natl Acad Sci U S A 2006; 103:12400-4. [PMID: 16895988 PMCID: PMC1567891 DOI: 10.1073/pnas.0603488103] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Flaviviruses, such as West Nile virus (WNV), are significant human pathogens. The humoral immune response plays an important role in the control of flavivirus infection and disease. The structure of WNV complexed with the Fab fragment of the strongly neutralizing mAb E16 was determined to 14.5-Angstrom resolution with cryo-electron microscopy. E16, an antibody with therapeutic potential, binds to domain III of the WNV envelope glycoprotein. Because of steric hindrance, Fab E16 binds to only 120 of the 180 possible binding sites on the viral surface. Fitting of the previously determined x-ray structure of the Fab-domain III complex into the cryo-electron microscopy density required a change of the elbow angle between the variable and constant domains of the Fab. The structure suggests that the E16 antibody neutralizes WNV by blocking the initial rearrangement of the E glycoprotein before fusion with a cellular membrane.
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Affiliation(s)
- Bärbel Kaufmann
- *Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054; and Departments of
| | | | - Paul R. Chipman
- *Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054; and Departments of
| | - Wei Zhang
- *Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054; and Departments of
| | | | - Daved H. Fremont
- Pathology and Immunology
- Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110
| | - Richard J. Kuhn
- *Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054; and Departments of
| | - Michael G. Rossmann
- *Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054; and Departments of
- To whom correspondence should be addressed. E-mail:
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291
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Abstract
Since its entry into North America in 1999, West Nile virus has spread throughout the USA and Canada, and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to potentially lethal encephalitis. Although no therapy is currently approved for use in humans, several strategies are being pursued to develop effective prophylaxis and treatments. This review describes the epidemiology, clinical presentation and pathogenesis of West Nile virus infection, and highlights recent progress towards an effective therapy.
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Affiliation(s)
- Michael S Diamond
- Department of Medicine, Washington University School of Medicine, Box 8051, St Louis, MO 63110, USA.
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292
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Zulueta A, Martín J, Hermida L, Alvarez M, Valdés I, Prado I, Chinea G, Rosario D, Guillén G, Guzmán MG. Amino acid changes in the recombinant Dengue 3 Envelope domain III determine its antigenicity and immunogenicity in mice. Virus Res 2006; 121:65-73. [PMID: 16781791 DOI: 10.1016/j.virusres.2006.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Revised: 04/07/2006] [Accepted: 04/18/2006] [Indexed: 11/21/2022]
Abstract
The immunogenicity of the Envelope fragment from amino acid 284 to 426 of Dengue viruses, obtained as fusion proteins with P64k in Escherichia coli, has been previously tested by our group. Here, we studied two fusion proteins with P64k carrying the Envelope fragment from two strains of Dengue 3: H87 prototype strain (PD9) and an isolate from the Nicaragua 1994 outbreak (PD18). Sequence comparison of the Dengue Envelope fragments showed four amino acid differences. Only PD18 reacted with human antisera and induced a higher functional immune response in mice than PD9. Moreover, mice immunized with PD18 were less susceptible to Dengue 3 administered intracerebrally than those immunized with PD9. The results reveal that not all sequences of the Dengue Envelope fragment, at least in the context of P64k, are antigenic and generate a functional immune response against the native virus. This finding has direct implications for the design of vaccines based on fragments of the Envelope protein.
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Affiliation(s)
- Aída Zulueta
- Vaccines Division, Center for Genetic Engineering and Biotechnology, Ave. 31 E/158 y 190, P.O. Box 6162, CP 10600, Cubanacán, Playa, Havana, Cuba.
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293
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Abstract
Background Antigen epitopes provide valuable information useful for disease prevention, diagnosis, and treatment. Recently, more and more databases focusing on different types of epitopes have become available. Conformational epitopes are an important form of epitope formed by residues that are sequentially discontinuous but close together in three-dimensional space. These epitopes have implicit structural information, making them attractive for both theoretical and applied biomedical research. However, most existing databases focus on linear rather than conformational epitopes. Description We describe CED, a special database of well defined conformational epitopes. CED provides a collection of conformational epitopes and related information including the residue make up and location of the epitope, the immunological property of the epitope, the source antigen and corresponding antibody of the epitope. All entries in this database are manually curated from articles published in peer review journals. The database can be browsed or searched through a user-friendly web interface. Most epitopes in CED can also be viewed interactively in the context of their 3D structures. In addition, the entries are also hyperlinked to various databases such as Swiss-Prot, PDB, KEGG and PubMed, providing wide background information. Conclusion A conformational epitope database called CED has been developed as an information resource for investigators involved in both theoretical and applied immunology research. It complements other existing specialised epitope databases. The database is freely available at
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Affiliation(s)
- Jian Huang
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
- School of Life Science and Technology, University of Electronic Science and Technology of China, China
| | - Wataru Honda
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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294
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Prabakaran P, Gan J, Feng Y, Zhu Z, Choudhry V, Xiao X, Ji X, Dimitrov DS. Structure of severe acute respiratory syndrome coronavirus receptor-binding domain complexed with neutralizing antibody. J Biol Chem 2006; 281:15829-36. [PMID: 16597622 PMCID: PMC8099238 DOI: 10.1074/jbc.m600697200] [Citation(s) in RCA: 207] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus (SARS-CoV, or SCV), which caused a world-wide epidemic in 2002 and 2003, binds to a receptor, angiotensin-converting enzyme 2 (ACE2), through the receptor-binding domain (RBD) of its envelope (spike, S) glycoprotein. The RBD is very immunogenic; it is a major SCV neutralization determinant and can elicit potent neutralizing antibodies capable of out-competing ACE2. However, the structural basis of RBD immunogenicity, RBD-mediated neutralization, and the role of RBD in entry steps following its binding to ACE2 have not been elucidated. By mimicking immune responses with the use of RBD as an antigen to screen a large human antibody library derived from healthy volunteers, we identified a novel potent cross-reactive SCV-neutralizing monoclonal antibody, m396, which competes with ACE2 for binding to RBD, and determined the crystal structure of the RBD-antibody complex at 2.3-Ä resolution. The antibody-bound RBD structure is completely defined, revealing two previously unresolved segments (residues 376–381 and 503–512) and a new disulfide bond (between residues 378 and 511). Interestingly, the overall structure of the m396-bound RBD is not significantly different from that of the ACE2-bound RBD. The antibody epitope is dominated by a 10-residue-long protruding β6–β7 loop with two putative ACE2-binding hotspot residues (Ile-489 and Tyr-491). These results provide a structural rationale for the function of a major determinant of SCV immunogenicity and neutralization, the development of SCV therapeutics based on the antibody paratope and epitope, and a retrovaccinology approach for the design of anti-SCV vaccines. The available structural information indicates that the SCV entry may not be mediated by ACE2-induced conformational changes in the RBD but may involve other conformational changes or/and yet to be identified coreceptors.
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Affiliation(s)
- Ponraj Prabakaran
- Protein Interactions Group, Center for Cancer Research Nanobiology Program, NCI, National Institutes of Health, Frederick, Maryland 21702, USA
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