18 results on '"Vanzetta F"'
Search Results
2. Specificity, cross-reactivity, and function of antibodies elicited by Zika virus infection
- Author
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Stettler, K, Beltramello, M, Espinosa, DA, Graham, V, Cassotta, A, Bianchi, S, Vanzetta, F, Minola, A, Jaconi, S, Mele, F, Foglierini, M, Pedotti, M, Simonelli, L, Dowall, S, Atkinson, B, Percivalle, E, Simmons, CP, Varani, L, Blum, J, Baldanti, F, Cameroni, E, Hewson, R, Harris, E, Lanzavecchia, A, Sallusto, F, Corti, D, Stettler, K, Beltramello, M, Espinosa, DA, Graham, V, Cassotta, A, Bianchi, S, Vanzetta, F, Minola, A, Jaconi, S, Mele, F, Foglierini, M, Pedotti, M, Simonelli, L, Dowall, S, Atkinson, B, Percivalle, E, Simmons, CP, Varani, L, Blum, J, Baldanti, F, Cameroni, E, Hewson, R, Harris, E, Lanzavecchia, A, Sallusto, F, and Corti, D
- Abstract
Zika virus (ZIKV), a mosquito-borne flavivirus with homology to Dengue virus (DENV), has become a public health emergency. By characterizing memory lymphocytes from ZIKV-infected patients, we dissected ZIKV-specific and DENV-cross-reactive immune responses. Antibodies to nonstructural protein 1 (NS1) were largely ZIKV-specific and were used to develop a serological diagnostic tool. In contrast, antibodies against E protein domain I/II (EDI/II) were cross-reactive and, although poorly neutralizing, potently enhanced ZIKV and DENV infection in vitro and lethally enhanced DENV disease in mice. Memory T cells against NS1 or E proteins were poorly cross-reactive, even in donors preexposed to DENV. The most potent neutralizing antibodies were ZIKV-specific and targeted EDIII or quaternary epitopes on infectious virus. An EDIII-specific antibody protected mice from lethal ZIKV infection, illustrating the potential for antibody-based therapy.
- Published
- 2016
3. Isolation of human monoclonal antibodies that potently neutralize human cytomegalovirus infection by targeting different epitopes on the gH/gL/UL128-131A complex
- Author
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Macagno, A, Bernasconi, N, Vanzetta, F, Dander, E, Sarasini, A, Revello, M, Gerna, G, Sallusto, F, Lanzavecchia, A, Bernasconi, NL, DANDER, ERICA, Revello, MG, Lanzavecchia, A., Macagno, A, Bernasconi, N, Vanzetta, F, Dander, E, Sarasini, A, Revello, M, Gerna, G, Sallusto, F, Lanzavecchia, A, Bernasconi, NL, DANDER, ERICA, Revello, MG, and Lanzavecchia, A.
- Abstract
Human cytomegalovirus (HCMV) is a widely circulating pathogen that causes severe disease in immunocompromised patients and infected fetuses. By immortalizing memory B cells from HCMV-immune donors, we isolated a panel of human monoclonal antibodies that neutralized at extremely low concentrations (90% inhibitory concentration [IC90] values ranging from 5 to 200 pM) HCMV infection of endothelial, epithelial, and myeloid cells. With the single exception of an antibody that bound to a conserved epitope in the UL128 gene product, all other antibodies bound to conformational epitopes that required expression of two or more proteins of the gH/gL/UL128-131A complex. Antibodies against gB, gH, or gM/gN were also isolated and, albeit less potent, were able to neutralize infection of both endothelial-epithelial cells and fibroblasts. This study describes unusually potent neutralizing antibodies against HCMV that might be used for passive immunotherapy and identifies, through the use of such antibodies, novel antigenic targets in HCMV for the design of immunogens capable of eliciting previously unknown neutralizing antibody responses. Copyright © 2010, American Society for Microbiology.
- Published
- 2010
4. STRUCTURE OF INFLUENZA A NEUTRALIZING ANTIBODY SELECTED FROM CULTURES OF SINGLE HUMAN PLASMA CELLS IN COMPLEX WITH HUMAN H1 INFLUENZA HAEMAGGLUTININ.
- Author
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Hubbard, P.A., primary, Ritchie, A.J., additional, Corti, D., additional, Voss, J.E., additional, Gamblin, S.J., additional, Codoni, G., additional, Macagno, A., additional, Jarrossay, D., additional, Pinna, D., additional, Minola, A., additional, Vanzetta, F., additional, Silacci, C., additional, Fernandez-Rodriguez, B.M., additional, Agatic, G., additional, Giacchetto-Sasselli, I., additional, Vachieri, S.G., additional, Sallusto, F., additional, Collins, P.J., additional, Haire, L.F., additional, Temperton, N., additional, Langedijk, J.P.M., additional, Skehel, J.J., additional, and Lanzavecchia, A., additional
- Published
- 2011
- Full Text
- View/download PDF
5. crystal structure of the HK20 Fab in complex with a gp41 mimetic 5- Helix
- Author
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Sabin, C., primary, Corti, D., additional, Buzon, V., additional, Seaman, M.S., additional, Lutje Hulsik, D., additional, Hinz, A., additional, Vanzetta, F., additional, Agatic, G., additional, Silacci, C., additional, Langedijk, J.P.M., additional, Mainetti, L., additional, Scarlatti, G., additional, Sallusto, F., additional, Weiss, R., additional, Lanzavecchia, A., additional, and Weissenhorn, W., additional
- Published
- 2010
- Full Text
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6. Isolation of human monoclonal antibodies that potently neutralize human cytomegalovirus infection by targeting different epitopes on the gH/gL/UL128-131A complex
- Author
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Giuseppe Gerna, Antonella Sarasini, Maria Grazia Revello, Nadia L. Bernasconi, Erica Dander, Fabrizia Vanzetta, Annalisa Macagno, Federica Sallusto, Antonio Lanzavecchia, Macagno, A, Bernasconi, N, Vanzetta, F, Dander, E, Sarasini, A, Revello, M, Gerna, G, Sallusto, F, and Lanzavecchia, A
- Subjects
Human cytomegalovirus ,Cytomegalovirus Infection ,Cytomegalovirus ,Antibodies, Viral ,Epitope ,Epitopes ,Mice ,0302 clinical medicine ,Viral Envelope Proteins ,Pregnancy ,Pregnancy Complications, Infectious ,Neutralizing antibody ,0303 health sciences ,Membrane Glycoproteins ,biology ,Antibodies, Monoclonal ,Viral Envelope Protein ,3. Good health ,Cytomegalovirus Infections ,Female ,Membrane Glycoprotein ,Antibody ,Neutralization Test ,medicine.drug ,Human ,medicine.drug_class ,Immunology ,Molecular Sequence Data ,Congenital cytomegalovirus infection ,Monoclonal antibody ,Microbiology ,Cell Line ,03 medical and health sciences ,Antigen ,Neutralization Tests ,Virology ,medicine ,Animals ,Humans ,Amino Acid Sequence ,030304 developmental biology ,Animal ,Cytomegaloviru ,medicine.disease ,Antibodies, Neutralizing ,Insect Science ,biology.protein ,Pregnancy Complications, Infectiou ,Pathogenesis and Immunity ,Cytomegalovirus vaccine ,030215 immunology - Abstract
Human cytomegalovirus (HCMV) is a widely circulating pathogen that causes severe disease in immunocompromised patients and infected fetuses. By immortalizing memory B cells from HCMV-immune donors, we isolated a panel of human monoclonal antibodies that neutralized at extremely low concentrations (90% inhibitory concentration [IC 90 ] values ranging from 5 to 200 pM) HCMV infection of endothelial, epithelial, and myeloid cells. With the single exception of an antibody that bound to a conserved epitope in the UL128 gene product, all other antibodies bound to conformational epitopes that required expression of two or more proteins of the gH/gL/UL128-131A complex. Antibodies against gB, gH, or gM/gN were also isolated and, albeit less potent, were able to neutralize infection of both endothelial-epithelial cells and fibroblasts. This study describes unusually potent neutralizing antibodies against HCMV that might be used for passive immunotherapy and identifies, through the use of such antibodies, novel antigenic targets in HCMV for the design of immunogens capable of eliciting previously unknown neutralizing antibody responses.
- Published
- 2009
7. Specificity, cross-reactivity, and function of antibodies elicited by Zika virus infection.
- Author
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Stettler K, Beltramello M, Espinosa DA, Graham V, Cassotta A, Bianchi S, Vanzetta F, Minola A, Jaconi S, Mele F, Foglierini M, Pedotti M, Simonelli L, Dowall S, Atkinson B, Percivalle E, Simmons CP, Varani L, Blum J, Baldanti F, Cameroni E, Hewson R, Harris E, Lanzavecchia A, Sallusto F, and Corti D
- Subjects
- Animals, Antibodies, Monoclonal chemistry, Antibodies, Monoclonal therapeutic use, Antibodies, Neutralizing chemistry, Antibodies, Neutralizing therapeutic use, Antibodies, Viral chemistry, Antibodies, Viral therapeutic use, Antibody Specificity, Cross Reactions, Dengue Virus immunology, Disease Models, Animal, Humans, Immunodominant Epitopes immunology, Immunologic Memory, Protein Structure, Tertiary, T-Lymphocytes immunology, Viral Envelope Proteins immunology, Viral Nonstructural Proteins immunology, Zika Virus Infection prevention & control, Zika Virus Infection therapy, Antibodies, Monoclonal immunology, Antibodies, Neutralizing immunology, Antibodies, Viral immunology, Zika Virus immunology, Zika Virus Infection immunology
- Abstract
Zika virus (ZIKV), a mosquito-borne flavivirus with homology to Dengue virus (DENV), has become a public health emergency. By characterizing memory lymphocytes from ZIKV-infected patients, we dissected ZIKV-specific and DENV-cross-reactive immune responses. Antibodies to nonstructural protein 1 (NS1) were largely ZIKV-specific and were used to develop a serological diagnostic tool. In contrast, antibodies against E protein domain I/II (EDI/II) were cross-reactive and, although poorly neutralizing, potently enhanced ZIKV and DENV infection in vitro and lethally enhanced DENV disease in mice. Memory T cells against NS1 or E proteins were poorly cross-reactive, even in donors preexposed to DENV. The most potent neutralizing antibodies were ZIKV-specific and targeted EDIII or quaternary epitopes on infectious virus. An EDIII-specific antibody protected mice from lethal ZIKV infection, illustrating the potential for antibody-based therapy., (Copyright © 2016, American Association for the Advancement of Science.)
- Published
- 2016
- Full Text
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8. Structure and Function Analysis of an Antibody Recognizing All Influenza A Subtypes.
- Author
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Kallewaard NL, Corti D, Collins PJ, Neu U, McAuliffe JM, Benjamin E, Wachter-Rosati L, Palmer-Hill FJ, Yuan AQ, Walker PA, Vorlaender MK, Bianchi S, Guarino B, De Marco A, Vanzetta F, Agatic G, Foglierini M, Pinna D, Fernandez-Rodriguez B, Fruehwirth A, Silacci C, Ogrodowicz RW, Martin SR, Sallusto F, Suzich JA, Lanzavecchia A, Zhu Q, Gamblin SJ, and Skehel JJ
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Monoclonal chemistry, Antibodies, Monoclonal isolation & purification, Antibodies, Monoclonal, Humanized, Antibodies, Neutralizing chemistry, Antibodies, Neutralizing immunology, Antibodies, Neutralizing isolation & purification, Antibodies, Viral chemistry, Antibodies, Viral isolation & purification, Binding Sites, Antibody, Crystallography, X-Ray, Epitopes immunology, Ferrets, Humans, Influenza Vaccines, Mice, Orthomyxoviridae Infections prevention & control, Protein Conformation, Antibodies, Monoclonal immunology, Antibodies, Viral immunology, Antibody Specificity, Alphainfluenzavirus immunology
- Abstract
Influenza virus remains a threat because of its ability to evade vaccine-induced immune responses due to antigenic drift. Here, we describe the isolation, evolution, and structure of a broad-spectrum human monoclonal antibody (mAb), MEDI8852, effectively reacting with all influenza A hemagglutinin (HA) subtypes. MEDI8852 uses the heavy-chain VH6-1 gene and has higher potency and breadth when compared to other anti-stem antibodies. MEDI8852 is effective in mice and ferrets with a therapeutic window superior to that of oseltamivir. Crystallographic analysis of Fab alone or in complex with H5 or H7 HA proteins reveals that MEDI8852 binds through a coordinated movement of CDRs to a highly conserved epitope encompassing a hydrophobic groove in the fusion domain and a large portion of the fusion peptide, distinguishing it from other structurally characterized cross-reactive antibodies. The unprecedented breadth and potency of neutralization by MEDI8852 support its development as immunotherapy for influenza virus-infected humans., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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9. Development of broad-spectrum human monoclonal antibodies for rabies post-exposure prophylaxis.
- Author
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De Benedictis P, Minola A, Rota Nodari E, Aiello R, Zecchin B, Salomoni A, Foglierini M, Agatic G, Vanzetta F, Lavenir R, Lepelletier A, Bentley E, Weiss R, Cattoli G, Capua I, Sallusto F, Wright E, Lanzavecchia A, Bourhy H, and Corti D
- Subjects
- Animals, Antibodies, Monoclonal administration & dosage, Antibodies, Monoclonal isolation & purification, Antibodies, Neutralizing administration & dosage, Antibodies, Neutralizing isolation & purification, Antibodies, Viral administration & dosage, Antibodies, Viral isolation & purification, Disease Models, Animal, Humans, Immunization, Passive methods, Immunologic Factors administration & dosage, Immunologic Factors isolation & purification, Mesocricetus, Survival Analysis, Treatment Outcome, Antibodies, Monoclonal immunology, Antibodies, Neutralizing immunology, Antibodies, Viral immunology, Immunologic Factors immunology, Post-Exposure Prophylaxis methods, Rabies prevention & control, Rabies virus immunology
- Abstract
Currently available rabies post-exposure prophylaxis (PEP) for use in humans includes equine or human rabies immunoglobulins (RIG). The replacement of RIG with an equally or more potent and safer product is strongly encouraged due to the high costs and limited availability of existing RIG. In this study, we identified two broadly neutralizing human monoclonal antibodies that represent a valid and affordable alternative to RIG in rabies PEP. Memory B cells from four selected vaccinated donors were immortalized and monoclonal antibodies were tested for neutralizing activity and epitope specificity. Two antibodies, identified as RVC20 and RVC58 (binding to antigenic site I and III, respectively), were selected for their potency and broad-spectrum reactivity. In vitro, RVC20 and RVC58 were able to neutralize all 35 rabies virus (RABV) and 25 non-RABV lyssaviruses. They showed higher potency and breath compared to antibodies under clinical development (namely CR57, CR4098, and RAB1) and commercially available human RIG. In vivo, the RVC20-RVC58 cocktail protected Syrian hamsters from a lethal RABV challenge and did not affect the endogenous hamster post-vaccination antibody response., (© 2016 Humabs BioMed SA Published under the terms of the CC BY 4.0 license.)
- Published
- 2016
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10. Protective monotherapy against lethal Ebola virus infection by a potently neutralizing antibody.
- Author
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Corti D, Misasi J, Mulangu S, Stanley DA, Kanekiyo M, Wollen S, Ploquin A, Doria-Rose NA, Staupe RP, Bailey M, Shi W, Choe M, Marcus H, Thompson EA, Cagigi A, Silacci C, Fernandez-Rodriguez B, Perez L, Sallusto F, Vanzetta F, Agatic G, Cameroni E, Kisalu N, Gordon I, Ledgerwood JE, Mascola JR, Graham BS, Muyembe-Tamfun JJ, Trefry JC, Lanzavecchia A, and Sullivan NJ
- Subjects
- Adult, Animals, Antibodies, Monoclonal immunology, Antibodies, Monoclonal isolation & purification, Antibodies, Neutralizing immunology, Antibodies, Neutralizing isolation & purification, Antibodies, Viral immunology, Antibodies, Viral isolation & purification, Clinical Trials as Topic, Disease Outbreaks, Female, Hemorrhagic Fever, Ebola epidemiology, Humans, Macaca, Male, Molecular Sequence Data, Survivors, Antibodies, Monoclonal administration & dosage, Antibodies, Neutralizing administration & dosage, Antibodies, Viral administration & dosage, Ebolavirus immunology, Hemorrhagic Fever, Ebola prevention & control
- Abstract
Ebola virus disease in humans is highly lethal, with case fatality rates ranging from 25 to 90%. There is no licensed treatment or vaccine against the virus, underscoring the need for efficacious countermeasures. We ascertained that a human survivor of the 1995 Kikwit Ebola virus disease outbreak maintained circulating antibodies against the Ebola virus surface glycoprotein for more than a decade after infection. From this survivor we isolated monoclonal antibodies (mAbs) that neutralize recent and previous outbreak variants of Ebola virus and mediate antibody-dependent cell-mediated cytotoxicity in vitro. Strikingly, monotherapy with mAb114 protected macaques when given as late as 5 days after challenge. Treatment with a single human mAb suggests that a simplified therapeutic strategy for human Ebola infection may be possible., (Copyright © 2016, American Association for the Advancement of Science.)
- Published
- 2016
- Full Text
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11. Prophylactic and postexposure efficacy of a potent human monoclonal antibody against MERS coronavirus.
- Author
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Corti D, Zhao J, Pedotti M, Simonelli L, Agnihothram S, Fett C, Fernandez-Rodriguez B, Foglierini M, Agatic G, Vanzetta F, Gopal R, Langrish CJ, Barrett NA, Sallusto F, Baric RS, Varani L, Zambon M, Perlman S, and Lanzavecchia A
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Neutralizing immunology, Antibodies, Viral immunology, B-Lymphocytes immunology, Binding Sites, CHO Cells, Coronavirus Infections immunology, Coronavirus Infections virology, Cricetinae, Cricetulus, Dipeptidyl Peptidase 4 chemistry, Enzyme-Linked Immunosorbent Assay, Female, Humans, Male, Mice, Mice, Inbred BALB C, Middle Aged, Molecular Conformation, Molecular Sequence Data, Mutation, Protein Binding, Sequence Homology, Amino Acid, Spike Glycoprotein, Coronavirus chemistry, Viral Vaccines, Antibodies, Monoclonal immunology, Immunologic Memory, Middle East Respiratory Syndrome Coronavirus drug effects
- Abstract
Middle East Respiratory Syndrome (MERS) is a highly lethal pulmonary infection caused by a previously unidentified coronavirus (CoV), likely transmitted to humans by infected camels. There is no licensed vaccine or antiviral for MERS, therefore new prophylactic and therapeutic strategies to combat human infections are needed. In this study, we describe, for the first time, to our knowledge, the isolation of a potent MERS-CoV-neutralizing antibody from memory B cells of an infected individual. The antibody, named LCA60, binds to a novel site on the spike protein and potently neutralizes infection of multiple MERS-CoV isolates by interfering with the binding to the cellular receptor CD26. Importantly, using mice transduced with adenovirus expressing human CD26 and infected with MERS-CoV, we show that LCA60 can effectively protect in both prophylactic and postexposure settings. This antibody can be used for prophylaxis, for postexposure prophylaxis of individuals at risk, or for the treatment of human cases of MERS-CoV infection. The fact that it took only 4 mo from the initial screening of B cells derived from a convalescent patient for the development of a stable chinese hamster ovary (CHO) cell line producing neutralizing antibodies at more than 5 g/L provides an example of a rapid pathway toward the generation of effective antiviral therapies against emerging viruses.
- Published
- 2015
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12. Cross-neutralization of four paramyxoviruses by a human monoclonal antibody.
- Author
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Corti D, Bianchi S, Vanzetta F, Minola A, Perez L, Agatic G, Guarino B, Silacci C, Marcandalli J, Marsland BJ, Piralla A, Percivalle E, Sallusto F, Baldanti F, and Lanzavecchia A
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Monoclonal chemistry, Antibodies, Monoclonal isolation & purification, Antibodies, Monoclonal therapeutic use, Antibodies, Neutralizing chemistry, Antibodies, Neutralizing isolation & purification, Antibodies, Neutralizing therapeutic use, Antibody Specificity immunology, Cattle, Epitopes immunology, Humans, Immunoglobulin Light Chains chemistry, Immunoglobulin Light Chains immunology, Immunoglobulin Variable Region chemistry, Immunoglobulin Variable Region immunology, Metapneumovirus immunology, Mice, Models, Molecular, Molecular Sequence Data, Murine pneumonia virus immunology, Paramyxoviridae Infections prevention & control, Paramyxoviridae Infections therapy, Pneumovirus Infections immunology, Pneumovirus Infections prevention & control, Pneumovirus Infections virology, Respiratory Syncytial Virus Infections immunology, Respiratory Syncytial Virus Infections prevention & control, Respiratory Syncytial Virus Infections therapy, Respiratory Syncytial Virus Infections virology, Respiratory Syncytial Virus, Bovine immunology, Respiratory Syncytial Virus, Human immunology, Viral Fusion Proteins chemistry, Viral Fusion Proteins immunology, Viral Vaccines chemistry, Viral Vaccines immunology, Antibodies, Monoclonal immunology, Antibodies, Neutralizing immunology, Cross Reactions immunology, Paramyxoviridae classification, Paramyxoviridae immunology, Paramyxoviridae Infections immunology, Paramyxoviridae Infections virology
- Abstract
Broadly neutralizing antibodies reactive against most and even all variants of the same viral species have been described for influenza and HIV-1 (ref. 1). However, whether a neutralizing antibody could have the breadth of range to target different viral species was unknown. Human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV) are common pathogens that cause severe disease in premature newborns, hospitalized children and immune-compromised patients, and play a role in asthma exacerbations. Although antisera generated against either HRSV or HMPV are not cross-neutralizing, we speculated that, because of the repeated exposure to these viruses, cross-neutralizing antibodies may be selected in some individuals. Here we describe a human monoclonal antibody (MPE8) that potently cross-neutralizes HRSV and HMPV as well as two animal paramyxoviruses: bovine RSV (BRSV) and pneumonia virus of mice (PVM). In its germline configuration, MPE8 is HRSV-specific and its breadth is achieved by somatic mutations in the light chain variable region. MPE8 did not result in the selection of viral escape mutants that evaded antibody targeting and showed potent prophylactic efficacy in animal models of HRSV and HMPV infection, as well as prophylactic and therapeutic efficacy in the more relevant model of lethal PVM infection. The core epitope of MPE8 was mapped on two highly conserved anti-parallel β-strands on the pre-fusion viral F protein, which are rearranged in the post-fusion F protein conformation. Twenty-six out of the thirty HRSV-specific neutralizing antibodies isolated were also found to be specific for the pre-fusion F protein. Taken together, these results indicate that MPE8 might be used for the prophylaxis and therapy of severe HRSV and HMPV infections and identify the pre-fusion F protein as a candidate HRSV vaccine.
- Published
- 2013
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13. Pemphigus autoantibodies generated through somatic mutations target the desmoglein-3 cis-interface.
- Author
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Di Zenzo G, Di Lullo G, Corti D, Calabresi V, Sinistro A, Vanzetta F, Didona B, Cianchini G, Hertl M, Eming R, Amagai M, Ohyama B, Hashimoto T, Sloostra J, Sallusto F, Zambruno G, and Lanzavecchia A
- Subjects
- Amino Acid Sequence, Animals, Animals, Newborn, Antigen-Antibody Reactions, Autoantigens chemistry, Cells, Cultured, Complementarity Determining Regions immunology, Desmoglein 3 chemistry, Epitopes chemistry, Epitopes immunology, Humans, Immunization, Passive, Immunoglobulin Variable Region genetics, Keratinocytes immunology, Mice, Mice, Inbred C57BL, Molecular Sequence Data, Protein Conformation, Protein Structure, Tertiary, Sequence Alignment, Sequence Homology, Amino Acid, Autoantibodies immunology, Autoantigens immunology, Desmoglein 3 immunology, Immunoglobulin G immunology, Pemphigus immunology, Somatic Hypermutation, Immunoglobulin
- Abstract
Pemphigus vulgaris (PV) is an autoimmune blistering disease of skin and mucous membranes caused by autoantibodies to the desmoglein (DSG) family proteins DSG3 and DSG1, leading to loss of keratinocyte cell adhesion. To learn more about pathogenic PV autoantibodies, we isolated 15 IgG antibodies specific for DSG3 from 2 PV patients. Three antibodies disrupted keratinocyte monolayers in vitro, and 2 were pathogenic in a passive transfer model in neonatal mice. The epitopes recognized by the pathogenic antibodies were mapped to the DSG3 extracellular 1 (EC1) and EC2 subdomains, regions involved in cis-adhesive interactions. Using a site-specific serological assay, we found that the cis-adhesive interface on EC1 recognized by the pathogenic antibody PVA224 is the primary target of the autoantibodies present in the serum of PV patients. The autoantibodies isolated used different heavy- and light-chain variable region genes and carried high levels of somatic mutations in complementary-determining regions, consistent with antigenic selection. Remarkably, binding to DSG3 was lost when somatic mutations were reverted to the germline sequence. These findings identify the cis-adhesive interface of DSG3 as the immunodominant region targeted by pathogenic antibodies in PV and indicate that autoreactivity relies on somatic mutations generated in the response to an antigen unrelated to DSG3.
- Published
- 2012
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14. A neutralizing antibody selected from plasma cells that binds to group 1 and group 2 influenza A hemagglutinins.
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Corti D, Voss J, Gamblin SJ, Codoni G, Macagno A, Jarrossay D, Vachieri SG, Pinna D, Minola A, Vanzetta F, Silacci C, Fernandez-Rodriguez BM, Agatic G, Bianchi S, Giacchetto-Sasselli I, Calder L, Sallusto F, Collins P, Haire LF, Temperton N, Langedijk JP, Skehel JJ, and Lanzavecchia A
- Subjects
- Animals, Antibodies, Neutralizing isolation & purification, Antibodies, Viral isolation & purification, Antibody Specificity, Cells, Cultured, Cross Reactions, Crystallography, X-Ray, Epitopes immunology, Ferrets, Glycosylation, Humans, Hydrophobic and Hydrophilic Interactions, Immunization, Passive, Immunoglobulin Variable Region immunology, Influenza A Virus, H1N1 Subtype immunology, Influenza B virus immunology, Influenza, Human immunology, Mice, Models, Molecular, Molecular Sequence Data, Orthomyxoviridae Infections immunology, Orthomyxoviridae Infections prevention & control, Orthomyxoviridae Infections therapy, Plasma Cells immunology, Protein Multimerization, Protein Structure, Secondary, Antibodies, Neutralizing immunology, Antibodies, Viral immunology, Antigens, Viral immunology, Hemagglutinin Glycoproteins, Influenza Virus immunology, Influenza A virus immunology
- Abstract
The isolation of broadly neutralizing antibodies against influenza A viruses has been a long-sought goal for therapeutic approaches and vaccine design. Using a single-cell culture method for screening large numbers of human plasma cells, we isolated a neutralizing monoclonal antibody that recognized the hemagglutinin (HA) glycoprotein of all 16 subtypes and neutralized both group 1 and group 2 influenza A viruses. Passive transfer of this antibody conferred protection to mice and ferrets. Complexes with HAs from the group 1 H1 and the group 2 H3 subtypes analyzed by x-ray crystallography showed that the antibody bound to a conserved epitope in the F subdomain. This antibody may be used for passive protection and to inform vaccine design because of its broad specificity and neutralization potency.
- Published
- 2011
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15. An anti-HIV-1 V3 loop antibody fully protects cross-clade and elicits T-cell immunity in macaques mucosally challenged with an R5 clade C SHIV.
- Author
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Watkins JD, Siddappa NB, Lakhashe SK, Humbert M, Sholukh A, Hemashettar G, Wong YL, Yoon JK, Wang W, Novembre FJ, Villinger F, Ibegbu C, Patel K, Corti D, Agatic G, Vanzetta F, Bianchi S, Heeney JL, Sallusto F, Lanzavecchia A, and Ruprecht RM
- Subjects
- Animals, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Cell Proliferation, Enzyme-Linked Immunosorbent Assay, Lymphocytes cytology, Lymphocytes immunology, Macaca, Macaca mulatta, RNA, Viral genetics, Antibodies, Monoclonal immunology, HIV Antibodies immunology, T-Lymphocytes immunology
- Abstract
Neutralizing antibodies have been shown to protect macaques against SHIV challenge. However, genetically diverse HIV-1 clades have evolved, and a key question left unanswered is whether neutralizing antibodies can confer cross-clade protection in vivo. The novel human monoclonal antibody HGN194 was isolated from an individual infected with an HIV-1 clade AG recombinant circulating recombinant form (CRF). HGN194 targets an epitope in the third hypervariable loop (V3) of HIV-1 gp120 and neutralizes a range of relatively neutralization-sensitive and resistant viruses. We evaluated the potential of HGN194 to protect infant rhesus monkeys against a SHIV encoding a primary CCR5-tropic HIV-1 clade C envelope. After high-dose mucosal challenge, all untreated controls became highly viremic while all HGN194-treated animals (50 mg/kg) were completely protected. When HGN194 was given at 1 mg/kg, one out of two monkeys remained aviremic, whereas the other had delayed, lower peak viremia. Interestingly, all protected monkeys given high-dose HGN194 developed Gag-specific proliferative responses of both CD4+ and CD8+ T cells. To test whether generation of the latter involved cryptic infection, we ablated CD8+ cells after HGN194 clearance. No viremia was detected in any protected monkeys, thus ruling out virus reservoirs. Thus, induction of CD8 T-cell immunity may have resulted from transient "Hit and Run" infection or cross priming via Ag-Ab-mediated cross-presentation. Together, our data identified the HGN194 epitope as protective and provide proof-of-concept that this anti-V3 loop mAb can prevent infection with sterilizing immunity after challenge with virus of a different clade, implying that V3 is a potential vaccine target.
- Published
- 2011
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16. Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.
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Sabin C, Corti D, Buzon V, Seaman MS, Lutje Hulsik D, Hinz A, Vanzetta F, Agatic G, Silacci C, Mainetti L, Scarlatti G, Sallusto F, Weiss R, Lanzavecchia A, and Weissenhorn W
- Subjects
- Antibodies, Monoclonal metabolism, Antibodies, Neutralizing metabolism, Crystallization, Crystallography, X-Ray, HIV Infections immunology, HIV Infections metabolism, HIV Infections pathology, HIV-1 metabolism, Humans, Immunoglobulin Fragments immunology, Immunoglobulin Fragments metabolism, Immunoglobulin G immunology, Immunoglobulin G metabolism, Mutation genetics, Neutralization Tests, Protein Conformation, Surface Plasmon Resonance, Antibodies, Monoclonal immunology, Antibodies, Neutralizing immunology, HIV Antibodies immunology, HIV Envelope Protein gp41 chemistry, HIV Envelope Protein gp41 physiology, HIV-1 immunology
- Abstract
The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.
- Published
- 2010
- Full Text
- View/download PDF
17. Analysis of memory B cell responses and isolation of novel monoclonal antibodies with neutralizing breadth from HIV-1-infected individuals.
- Author
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Corti D, Langedijk JP, Hinz A, Seaman MS, Vanzetta F, Fernandez-Rodriguez BM, Silacci C, Pinna D, Jarrossay D, Balla-Jhagjhoorsingh S, Willems B, Zekveld MJ, Dreja H, O'Sullivan E, Pade C, Orkin C, Jeffs SA, Montefiori DC, Davis D, Weissenhorn W, McKnight A, Heeney JL, Sallusto F, Sattentau QJ, Weiss RA, and Lanzavecchia A
- Subjects
- Amino Acid Sequence, Antibodies, Monoclonal chemistry, Antibodies, Neutralizing chemistry, Binding Sites, Antibody, CD4 Antigens immunology, Epitopes chemistry, HIV-1, Humans, Molecular Sequence Data, Antibodies, Monoclonal immunology, Antibodies, Neutralizing immunology, B-Lymphocytes immunology, HIV Infections immunology, Immunologic Memory
- Abstract
Background: The isolation of human monoclonal antibodies (mAbs) that neutralize a broad spectrum of primary HIV-1 isolates and the characterization of the human neutralizing antibody B cell response to HIV-1 infection are important goals that are central to the design of an effective antibody-based vaccine., Methods and Findings: We immortalized IgG(+) memory B cells from individuals infected with diverse clades of HIV-1 and selected on the basis of plasma neutralization profiles that were cross-clade and relatively potent. Culture supernatants were screened using various recombinant forms of the envelope glycoproteins (Env) in multiple parallel assays. We isolated 58 mAbs that were mapped to different Env surfaces, most of which showed neutralizing activity. One mAb in particular (HJ16) specific for a novel epitope proximal to the CD4 binding site on gp120 selectively neutralized a multi-clade panel of Tier-2 HIV-1 pseudoviruses, and demonstrated reactivity that was comparable in breadth, but distinct in neutralization specificity, to that of the other CD4 binding site-specific neutralizing mAb b12. A second mAb (HGN194) bound a conserved epitope in the V3 crown and neutralized all Tier-1 and a proportion of Tier-2 pseudoviruses tested, irrespective of clade. A third mAb (HK20) with broad neutralizing activity, particularly as a Fab fragment, recognized a highly conserved epitope in the HR-1 region of gp41, but showed striking assay-dependent selectivity in its activity., Conclusions: This study reveals that by using appropriate screening methods, a large proportion of memory B cells can be isolated that produce mAbs with HIV-1 neutralizing activity. Three of these mAbs show unusual breadth of neutralization and therefore add to the current panel of HIV-1 neutralizing antibodies with potential for passive protection and template-based vaccine design.
- Published
- 2010
- Full Text
- View/download PDF
18. Isolation of human monoclonal antibodies that potently neutralize human cytomegalovirus infection by targeting different epitopes on the gH/gL/UL128-131A complex.
- Author
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Macagno A, Bernasconi NL, Vanzetta F, Dander E, Sarasini A, Revello MG, Gerna G, Sallusto F, and Lanzavecchia A
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Viral immunology, Antibodies, Viral isolation & purification, Cell Line, Cytomegalovirus Infections immunology, Cytomegalovirus Infections virology, Female, Humans, Mice, Molecular Sequence Data, Neutralization Tests, Pregnancy, Pregnancy Complications, Infectious immunology, Pregnancy Complications, Infectious virology, Viral Envelope Proteins chemistry, Viral Envelope Proteins genetics, Antibodies, Monoclonal immunology, Antibodies, Monoclonal isolation & purification, Antibodies, Neutralizing immunology, Antibodies, Neutralizing isolation & purification, Cytomegalovirus immunology, Epitopes chemistry, Epitopes immunology, Membrane Glycoproteins chemistry, Membrane Glycoproteins genetics, Membrane Glycoproteins immunology, Viral Envelope Proteins immunology
- Abstract
Human cytomegalovirus (HCMV) is a widely circulating pathogen that causes severe disease in immunocompromised patients and infected fetuses. By immortalizing memory B cells from HCMV-immune donors, we isolated a panel of human monoclonal antibodies that neutralized at extremely low concentrations (90% inhibitory concentration [IC(90)] values ranging from 5 to 200 pM) HCMV infection of endothelial, epithelial, and myeloid cells. With the single exception of an antibody that bound to a conserved epitope in the UL128 gene product, all other antibodies bound to conformational epitopes that required expression of two or more proteins of the gH/gL/UL128-131A complex. Antibodies against gB, gH, or gM/gN were also isolated and, albeit less potent, were able to neutralize infection of both endothelial-epithelial cells and fibroblasts. This study describes unusually potent neutralizing antibodies against HCMV that might be used for passive immunotherapy and identifies, through the use of such antibodies, novel antigenic targets in HCMV for the design of immunogens capable of eliciting previously unknown neutralizing antibody responses.
- Published
- 2010
- Full Text
- View/download PDF
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