10 results on '"Eldar Peretz"'
Search Results
2. Characterization of antibody-antigen interactions using biolayer interferometry
- Author
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Tal Noy-Porat, Ron Alcalay, Adva Mechaly, Eldar Peretz, Efi Makdasi, Ronit Rosenfeld, and Ohad Mazor
- Subjects
Immunology ,Antibody ,Protein Biochemistry ,Science (General) ,Q1-390 - Abstract
Summary: This protocol describes the use of a biolayer interferometry platform for assessing antibody-antigen interactions. The protocol focuses on affinity determination and epitope binning, although the system can be utilized for measuring any protein-protein interaction. Readings are collected in real time, allowing the use of unlabeled molecules, and data can thus be obtained in a fast and easy manner. Experiments should be carefully designed, taking into consideration the tested interaction, available sensors, and suitable controls.For complete details on the use and execution of this protocol, please refer to Noy-Porat et al. (2021).
- Published
- 2021
- Full Text
- View/download PDF
3. Immunodominant Linear B-Cell Epitopes of SARS-CoV-2 Spike, Identified by Sera from K18-hACE2 Mice Infected with the WT or Variant Viruses
- Author
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Yinon Levy, Ron Alcalay, Anat Zvi, Efi Makdasi, Eldar Peretz, Tal Noy-Porat, Theodor Chitlaru, Michal Mandelboim, Ohad Mazor, and Ronit Rosenfeld
- Subjects
COVID-19 ,SARS-CoV-2 ,epitope mapping ,linear epitopes ,K18-hACE2 ,Medicine - Abstract
SARS-CoV-2 surface spike protein mediates the viral entry into the host cell and represents the primary immunological target of COVID-19 vaccines as well as post-exposure immunotherapy. Establishment of the highly immunogenic B-cell epitope profile of SARS-CoV-2 proteins in general, and that of the spike protein in particular, may contribute to the development of sensitive diagnostic tools and identification of vaccine` candidate targets. In the current study, the anti-viral antibody response in transgenic K18-hACE-2 mice was examined by implementing an immunodominant epitope mapping approach of the SARS-CoV-2 spike. Serum samples for probing an epitope array covering the entire spike protein were collected from mice following infection with the original SARS-CoV-2 strain as well as the B.1.1.7 Alpha and B.1.351 Beta genetic variants of concern. The analysis resulted in distinction of six linear epitopes common to the humoral response against all virus variants inspected at a frequency of more than 20% of the serum samples. Finally, the universality of the response was probed by cross-protective in vitro experiments using plaque-reducing neutralization tests. The data presented here has important implications for prediction of the efficacy of immune countermeasures against emerging SARS-CoV-2 variants.
- Published
- 2022
- Full Text
- View/download PDF
4. Neutralizing Monoclonal Anti-SARS-CoV-2 Antibodies Isolated from Immunized Rabbits Define Novel Vulnerable Spike-Protein Epitope
- Author
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Efi Makdasi, Yinon Levy, Ron Alcalay, Tal Noy-Porat, Eran Zahavy, Adva Mechaly, Eyal Epstein, Eldar Peretz, Hila Cohen, Liat Bar-On, Theodor Chitlaru, Ofer Cohen, Itai Glinert, Hagit Achdout, Tomer Israely, Ronit Rosenfeld, and Ohad Mazor
- Subjects
COVID-19 ,SARS-CoV-2 ,neutralizing antibody ,monoclonal antibody ,single-cell sort ,spike ,Microbiology ,QR1-502 - Abstract
Monoclonal antibodies represent an important avenue for COVID-19 therapy and are routinely used for rapid and accessible diagnosis of SARS-CoV-2 infection. The recent emergence of SARS-CoV-2 genetic variants emphasized the need to enlarge the repertoire of antibodies that target diverse epitopes, the combination of which may improve immune-diagnostics, augment the efficiency of the immunotherapy and prevent selection of escape-mutants. Antigen-specific controlled immunization of experimental animals may elicit antibody repertoires that significantly differ from those generated in the context of the immune response mounted in the course of disease. Accordingly, rabbits were immunized by several recombinant antigens representing distinct domains of the viral spike protein and monoclonal antibodies were isolated from single cells obtained by cell sorting. Characterization of a panel of successfully isolated anti-receptor binding domain (RBD) and anti-N-terminal domain (NTD) antibodies demonstrated that they exhibit high specificity and affinity profiles. Anti-RBD antibodies revealing significant neutralizing potency against SARS-CoV-2 in vitro were found to target at least three distinct epitopes. Epitope mapping established that two of these antibodies recognized a novel epitope located on the surface of the RBD. We suggest that the antibodies isolated in this study are useful for designing SARS-CoV-2 diagnosis and therapy approaches.
- Published
- 2021
- Full Text
- View/download PDF
5. The neutralization potency of anti-SARS-CoV-2 therapeutic human monoclonal antibodies is retained against novel viral variants
- Author
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Efi Makdasi, Anat Zvi, Ron Alcalay, Tal Noy-Porat, Eldar Peretz, Adva Mechaly, Yinon Levy, Eyal Epstein, Theodor Chitlaru, Ariel Tennenhouse, Moshe Aftalion, David Gur, Nir Paran, Hadas Tamir, Oren Zimhony, Shay Weiss, Michal Mandelboim, Ella Mendelson, Neta Zuckerman, Ital Nemet, Limor Kliker, Shmuel Yitzhaki, Shmuel C. Shapira, Tomer Israely, Sarel J. Fleishman, Ohad Mazor, and Ronit Rosenfeld
- Subjects
chemistry.chemical_classification ,medicine.drug_class ,Biology ,Monoclonal antibody ,Virology ,Epitope ,Virus ,Neutralization ,In vitro ,chemistry ,medicine ,biology.protein ,Potency ,Antibody ,Glycoprotein - Abstract
SummaryA wide range of SARS-CoV-2 neutralizing monoclonal antibodies (mAbs) were reported to date, most of which target the spike glycoprotein and in particular its receptor binding domain (RBD) and N-terminal domain (NTD) of the S1 subunit. The therapeutic implementation of these antibodies has been recently challenged by emerging SARS-CoV-2 variants that harbor extensively mutated spike versions. Consequently, the re-assessment of mAbs, previously reported to neutralize the original early-version of the virus, is of high priority.Four previously selected mAbs targeting non-overlapping epitopes, were evaluated for their binding potency to RBD versions harboring individual mutations at spike positions 417, 439, 453, 477, 484 and 501. Mutations at these positions represent the prevailing worldwide distributed modifications of the RBD, previously reported to mediate escape from antibody neutralization. Additionally, the in vitro neutralization potencies of the four RBD-specific mAbs, as well as two NTD-specific mAbs, were evaluated against two frequent SARS-CoV-2 variants of concern (VOCs): (i) the B.1.1.7 variant, emerged in the UK and (ii) the B.1.351 variant, emerged in South Africa. Variant B.1.351 was previously suggested to escape many therapeutic mAbs, including those authorized for clinical use. The possible impact of RBD mutations on recognition by mAbs is addressed by comparative structural modelling. Finally, we demonstrate the therapeutic potential of three selected mAbs by treatment of K18-hACE2 transgenic mice two days post infection with each of the virus strains.Our results clearly indicate that despite the accumulation of spike mutations, some neutralizing mAbs preserve their potency against SARS-CoV-2. In particular, the highly potent MD65 and BL6 mAbs are shown to retain their ability to bind the prevalent novel viral mutations and to effectively protect against B.1.1.7 and B.1.351 variants of high clinical concern.
- Published
- 2021
6. Neutralizing Monoclonal Anti-SARS-CoV-2 Antibodies Isolated from Immunized Rabbits Define Novel Vulnerable Spike-Protein Epitope
- Author
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Eran Zahavy, Tal Noy-Porat, Theodor Chitlaru, Hila Cohen, Eyal Epstein, Itai Glinert, Adva Mechaly, Ofer Cohen, Yinon Levy, Ronit Rosenfeld, Ohad Mazor, Tomer Israely, Efi Makdasi, Ron Alcalay, Hagit Achdout, Liat Bar-On, and Eldar Peretz
- Subjects
0301 basic medicine ,medicine.drug_class ,lcsh:QR1-502 ,single-cell sort ,Biology ,Monoclonal antibody ,Antibodies, Viral ,Epitope ,Article ,lcsh:Microbiology ,03 medical and health sciences ,Epitopes ,0302 clinical medicine ,Antigen ,Neutralization Tests ,Virology ,medicine ,Animals ,Humans ,Neutralizing antibody ,SARS-CoV-2 ,COVID-19 ,neutralizing antibody ,rabbit immunization ,spike ,Antibodies, Neutralizing ,030104 developmental biology ,Infectious Diseases ,Epitope mapping ,Immunization ,monoclonal antibody ,030220 oncology & carcinogenesis ,Monoclonal ,Spike Glycoprotein, Coronavirus ,biology.protein ,Female ,Rabbits ,Antibody ,Epitope Mapping - Abstract
Monoclonal antibodies represent an important avenue for COVID-19 therapy and are routinely used for rapid and accessible diagnosis of SARS-CoV-2 infection. The recent emergence of SARS-CoV-2 genetic variants emphasized the need to enlarge the repertoire of antibodies that target diverse epitopes, the combination of which may improve immune-diagnostics, augment the efficiency of the immunotherapy and prevent selection of escape-mutants. Antigen-specific controlled immunization of experimental animals may elicit antibody repertoires that significantly differ from those generated in the context of the immune response mounted in the course of disease. Accordingly, rabbits were immunized by several recombinant antigens representing distinct domains of the viral spike protein and monoclonal antibodies were isolated from single cells obtained by cell sorting. Characterization of a panel of successfully isolated anti-receptor binding domain (RBD) and anti-N-terminal domain (NTD) antibodies demonstrated that they exhibit high specificity and affinity profiles. Anti-RBD antibodies revealing significant neutralizing potency against SARS-CoV-2 in vitro were found to target at least three distinct epitopes. Epitope mapping established that two of these antibodies recognized a novel epitope located on the surface of the RBD. We suggest that the antibodies isolated in this study are useful for designing SARS-CoV-2 diagnosis and therapy approaches.
- Published
- 2021
- Full Text
- View/download PDF
7. Tiger team: a panel of human neutralizing mAbs targeting SARS-CoV-2 spike at multiple epitopes
- Author
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Tal Noy-Porat, Efi Makdasi, Ron Alcalay, Adva Mechaly, Yinon Levy, Adi Bercovich-Kinori, Ayelet Zauberman, Hadas Tamir, Yfat Yahalom-Ronen, Ma’ayan Israeli, Eyal Epstein, Hagit Achdout, Sharon Melamed, Theodor Chitlaru, Shay Weiss, Eldar Peretz, Osnat Rosen, Nir Paran, Shmuel Yitzhaki, Shmuel C. Shapira, Tomer Israely, Ohad Mazor, and Ronit Rosenfeld
- Subjects
Phage display ,biology ,Coronavirus disease 2019 (COVID-19) ,medicine.drug_class ,viruses ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Monoclonal antibody ,Human coronavirus ,Virology ,Virus ,Epitope ,medicine ,biology.protein ,Antibody - Abstract
The novel highly transmissible human coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Thus far, there is no approved therapeutic drug, specifically targeting this emerging virus. Here we report the isolation and characterization of a panel of human neutralizing monoclonal antibodies targeting the SARS-CoV-2 receptor binding domain (RBD). These antibodies were selected from a phage display library constructed using peripheral circulatory lymphocytes collected from patients at the acute phase of the disease. These neutralizing antibodies are shown to recognize distinct epitopes on the viral spike RBD, therefore they represent a promising basis for the design of efficient combined post-exposure therapy for SARS-CoV-2 infection.
- Published
- 2020
8. A panel of human neutralizing mAbs targeting SARS-CoV-2 spike at multiple epitopes
- Author
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Adi Bercovich-Kinori, Hadas Tamir, Ayelet Zauberman, Efi Makdasi, Eyal Epstein, Osnat Rosen, Adva Mechaly, Shay Weiss, Theodor Chitlaru, Hagit Achdout, Tomer Israely, Tal Noy-Porat, Yfat Yahalom-Ronen, Nir Paran, Yinon Levy, Ronit Rosenfeld, Shmuel C. Shapira, Shmuel Yitzhaki, Sharon Melamed, Ohad Mazor, Ron Alcalay, Ma'ayan Israeli, and Eldar Peretz
- Subjects
0301 basic medicine ,Phage display ,medicine.drug_class ,medicine.medical_treatment ,Science ,viruses ,General Physics and Astronomy ,02 engineering and technology ,Peptidyl-Dipeptidase A ,Monoclonal antibody ,Antibodies, Viral ,Epitope ,Virus ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,Betacoronavirus ,Epitopes ,Peptide Library ,Chlorocebus aethiops ,medicine ,Animals ,Humans ,Protein Interaction Domains and Motifs ,Peptide library ,lcsh:Science ,Vero Cells ,Multidisciplinary ,biology ,SARS-CoV-2 ,Antibodies, Monoclonal ,Immunotherapy ,General Chemistry ,021001 nanoscience & nanotechnology ,Virology ,Antibodies, Neutralizing ,030104 developmental biology ,Epitope mapping ,Viral infection ,Spike Glycoprotein, Coronavirus ,biology.protein ,lcsh:Q ,Angiotensin-Converting Enzyme 2 ,Antibody ,0210 nano-technology ,Epitope Mapping ,Protein Binding - Abstract
The novel highly transmissible human coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Thus far, there is no approved therapeutic drug specifically targeting this emerging virus. Here we report the isolation and characterization of a panel of human neutralizing monoclonal antibodies targeting the SARS-CoV-2 receptor binding domain (RBD). These antibodies were selected from a phage display library constructed using peripheral circulatory lymphocytes collected from patients at the acute phase of the disease. These neutralizing antibodies are shown to recognize distinct epitopes on the viral spike RBD. A subset of the antibodies exert their inhibitory activity by abrogating binding of the RBD to the human ACE2 receptor. The human monoclonal antibodies described here represent a promising basis for the design of efficient combined post-exposure therapy for SARS-CoV-2 infection., Here, Noy-Porat, Makdasi et al. report the isolation of a panel of neutralizing mAbs selected against SARS-CoV-2 receptor-binding domain (RBD) from a phage display library constructed based on patient samples collected in the acute phase of the disease, which show efficient neutralizing activities against authentic virus in vitro.
- Published
- 2020
9. Immunodominant Linear B-Cell Epitopes of SARS-CoV-2 Spike, Identified by Sera from K18-hACE2 Mice Infected with the WT or Variant Viruses
- Author
-
Yinon Levy, Ron Alcalay, Anat Zvi, Efi Makdasi, Eldar Peretz, Tal Noy-Porat, Theodor Chitlaru, Michal Mandelboim, Ohad Mazor, and Ronit Rosenfeld
- Subjects
Pharmacology ,Infectious Diseases ,Drug Discovery ,Immunology ,Pharmacology (medical) ,COVID-19 ,SARS-CoV-2 ,epitope mapping ,linear epitopes ,K18-hACE2 - Abstract
SARS-CoV-2 surface spike protein mediates the viral entry into the host cell and represents the primary immunological target of COVID-19 vaccines as well as post-exposure immunotherapy. Establishment of the highly immunogenic B-cell epitope profile of SARS-CoV-2 proteins in general, and that of the spike protein in particular, may contribute to the development of sensitive diagnostic tools and identification of vaccine` candidate targets. In the current study, the anti-viral antibody response in transgenic K18-hACE-2 mice was examined by implementing an immunodominant epitope mapping approach of the SARS-CoV-2 spike. Serum samples for probing an epitope array covering the entire spike protein were collected from mice following infection with the original SARS-CoV-2 strain as well as the B.1.1.7 Alpha and B.1.351 Beta genetic variants of concern. The analysis resulted in distinction of six linear epitopes common to the humoral response against all virus variants inspected at a frequency of more than 20% of the serum samples. Finally, the universality of the response was probed by cross-protective in vitro experiments using plaque-reducing neutralization tests. The data presented here has important implications for prediction of the efficacy of immune countermeasures against emerging SARS-CoV-2 variants.
- Full Text
- View/download PDF
10. The neutralization potency of anti-SARS-CoV-2 therapeutic human monoclonal antibodies is retained against viral variants
- Author
-
Ron Alcalay, Shmuel C. Shapira, Moshe Aftalion, Tal Noy-Porat, Ella Mendelson, Limor Kliker, Nir Paran, Efi Makdasi, Michal Mandelboim, Eldar Peretz, Eyal Epstein, Sarel J. Fleishman, Ohad Mazor, Tomer Israely, Ariel Tennenhouse, Adva Mechaly, Theodor Chitlaru, Shay Weiss, Hadas Tamir, Yinon Levy, Shmuel Yitzhaki, Neta S. Zuckerman, David Gur, Ital Nemet, Ronit Rosenfeld, Oren Zimhony, and Anat Zvi
- Subjects
Genetically modified mouse ,K18-hACE2 mice ,Models, Molecular ,medicine.drug_class ,Antibody Affinity ,Mice, Transgenic ,mAbs ,Biology ,Monoclonal antibody ,General Biochemistry, Genetics and Molecular Biology ,Epitope ,Virus ,Neutralization ,Epitopes ,Mice ,Protein Domains ,Neutralization Tests ,Report ,medicine ,Potency ,Animals ,Humans ,neutralizing antibodies ,COVID-19 Serotherapy ,chemistry.chemical_classification ,variants ,SARS-CoV-2 ,Immunization, Passive ,VOCs ,Antibodies, Monoclonal ,COVID-19 ,escape mutants ,Virology ,Antibodies, Neutralizing ,Treatment Outcome ,chemistry ,Spike Glycoprotein, Coronavirus ,biology.protein ,Antibody ,Glycoprotein - Abstract
A wide range of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing monoclonal antibodies (mAbs) have been reported, most of which target the spike glycoprotein. Therapeutic implementation of these antibodies has been challenged by emerging SARS-CoV-2 variants harboring mutated spike versions. Consequently, re-assessment of previously identified mAbs is of high priority. Four previously selected mAbs targeting non-overlapping epitopes are now evaluated for binding potency to mutated RBD versions, reported to mediate escape from antibody neutralization. In vitro neutralization potencies of these mAbs, and two NTD-specific mAbs, are evaluated against two frequent SARS-CoV-2 variants of concern, the B.1.1.7 Alpha and the B.1.351 Beta. Furthermore, we demonstrate therapeutic potential of three selected mAbs by treatment of K18-human angiotensin-converting enzyme 2 (hACE2) transgenic mice 2 days post-infection with each virus variant. Thus, despite the accumulation of spike mutations, the highly potent MD65 and BL6 mAbs retain their ability to bind the prevalent viral mutants, effectively protecting against B.1.1.7 and B.1.351 variants., Graphical abstract, Novel SARS-CoV-2 antigenic variants jeopardize the efficacy of immunotherapies. Makdasi et al. re-evaluate anti-SARS-CoV-2 Abs previously shown to be highly effective against the original version of the virus. Some of the inspected antibodies retain their neutralization ability and in vivo protective efficacy against various viral variants.
- Full Text
- View/download PDF
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