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Abstract
The traditional method for generating polyclonal and monoclonal antibodies requires the immunization of an animal. Selecting the best species of animal and getting that animal's immune system to respond to a target antigen with an antibody response are essential to obtaining good-quality antibodies and hybridomas. There are only a limited number of opportunities for a researcher to intervene to manipulate and tailor the response to a particular antigen. Here we present advice and methods for designing the way in which the antigen is presented to the immune system (i.e., the immunization protocol), including the choice of animal, the antigen dose, the use of adjuvants, the route and number of injections, and the period between injections.
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Neves WLL, Mariuba LAM, Alves KCS, Coelho KF, Tarragô AM, Costa AG, Chaves YO, Victoria FDS, Victoria MB, Malheiro A. Development of an immunoassay for the detection of human IgG against hepatitis C virus proteins using magnetic beads and flow cytometry. BIOTECHNOL BIOTEC EQ 2020. [DOI: 10.1080/13102818.2020.1839355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Walter Luiz Lima Neves
- Post-graduate Program in Basic and Applied Immunology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Post-graduate Program in Biotechnology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
| | - Luis André Morais Mariuba
- Post-graduate Program in Basic and Applied Immunology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Post-graduate Program in Biotechnology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Leonidas & Maria Deane Research Institute, FIOCRUZ-Amazônia, Manaus, AM, Brazil
- Postgraduate Program Stricto sensu in Cellular and Molecular Biology of the Oswaldo Cruz Institute (PGBCM/IOC/Fiocruz), Rio de Janeiro, Brazil
| | - Késsia Caroline Souza Alves
- Post-graduate Program in Biotechnology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
| | - Kerolaine Fonseca Coelho
- Department of Education and Research, Amazonas Hospital Foundation of Hematology and Hemotherapy (HEMOAM), Manaus, AM, Brazil
- Post-graduate Program in Tropical Medicine, State University of Amazonas (UEA), Manaus, AM, Brazil
| | - Andrea Monteiro Tarragô
- Post-graduate Program in Basic and Applied Immunology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Department of Education and Research, Amazonas Hospital Foundation of Hematology and Hemotherapy (HEMOAM), Manaus, AM, Brazil
- Post-graduate Program in Tropical Medicine, State University of Amazonas (UEA), Manaus, AM, Brazil
| | - Allyson Guimarães Costa
- Post-graduate Program in Basic and Applied Immunology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Department of Education and Research, Amazonas Hospital Foundation of Hematology and Hemotherapy (HEMOAM), Manaus, AM, Brazil
- Post-graduate Program in Tropical Medicine, State University of Amazonas (UEA), Manaus, AM, Brazil
- Post-graduate Program in Hematology Sciences, State University of Amazonas (UEA), Manaus, AM, Brazil
- Carlos Borborema Clinical Research Institute, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), Manaus, AM, Brazil
| | - Yury Oliveira Chaves
- Post-graduate Program in Hematology Sciences, State University of Amazonas (UEA), Manaus, AM, Brazil
| | - Flamir da Silva Victoria
- Post-graduate Program in Hematology Sciences, State University of Amazonas (UEA), Manaus, AM, Brazil
- Carlos Borborema Clinical Research Institute, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), Manaus, AM, Brazil
| | - Marilu Barbieri Victoria
- Post-graduate Program in Hematology Sciences, State University of Amazonas (UEA), Manaus, AM, Brazil
- Carlos Borborema Clinical Research Institute, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), Manaus, AM, Brazil
| | - Adriana Malheiro
- Post-graduate Program in Basic and Applied Immunology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Post-graduate Program in Biotechnology, Institute of Biological Sciences, Federal University of Amazonas (UFAM), Manaus, AM, Brazil
- Post-graduate Program in Tropical Medicine, State University of Amazonas (UEA), Manaus, AM, Brazil
- Post-graduate Program in Hematology Sciences, State University of Amazonas (UEA), Manaus, AM, Brazil
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Liu Z, O’Rourke J. Expediting Antibody Discovery with a Cell and Bead Multiplexed Competition Assay. SLAS DISCOVERY 2018; 23:667-675. [DOI: 10.1177/2472555218776308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
With advances in molecular engineering and humanization, monoclonal antibodies are one of the fastest-growing classes of biopharmaceuticals. During antibody discovery, antibody from hybridoma or primary B-cell supernatants is screened for the desired binding characteristics, and secondary screens measure antibody function and concentration, identify immunoglobulin G (IgG) isotype, and assess cell health. In order to expedite the antibody discovery process, we developed a high-throughput, multiplexed cell and bead-based competition assay that identifies and quantitates mouse IgG isotypes and assesses cell health. No differences in assay performance were observed between single and multiplex formats. The linear range of the assay was from 0.5 to 50 µg/mL, and washing was not required, decreasing assay time and variability. Slight modifications to the protocol allowed quantification of dilute antibody supernatants (0.1–5 µg/mL). Using hybridoma cultures, we showed that cell viability measurements in the assay did not interfere with the bead-based IgG measurements. The assay described here is a simple mix-and-read, no-dilution screen that can reduce the time to antibody cloning and production. The high-content data can differentiate monoclonal and polyclonal wells, determine IgG quantity for downstream functional assays, provide isotype information, and monitor cell proliferation and viability.
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Affiliation(s)
- Zhaoping Liu
- Intellicyt, A Sartorius Brand, Albuquerque, NM, USA
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Kanner SA, Jain A, Colecraft HM. Development of a High-Throughput Flow Cytometry Assay to Monitor Defective Trafficking and Rescue of Long QT2 Mutant hERG Channels. Front Physiol 2018; 9:397. [PMID: 29725305 PMCID: PMC5917007 DOI: 10.3389/fphys.2018.00397] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/04/2018] [Indexed: 11/24/2022] Open
Abstract
Long QT Syndrome (LQTS) is an acquired or inherited disorder characterized by prolonged QT interval, exertion-triggered arrhythmias, and sudden cardiac death. One of the most prevalent hereditary LQTS subtypes, LQT2, results from loss-of-function mutations in the hERG channel, which conducts IKr, the rapid component of the delayed rectifier K+ current, critical for cardiac repolarization. The majority of LQT2 mutations result in Class 2 deficits characterized by impaired maturation and trafficking of hERG channels. Here, we have developed a high-throughput flow cytometric assay to analyze the surface and total expression of wild-type (WT) and mutant hERG channels with single-cell resolution. To test our method, we focused on 16 LQT2 mutations in the hERG Per-Arnt-Sim (PAS) domain that were previously studied via a widely used biochemical approach that compares levels of 135-kDa immature and 155-kDa fully glycosylated hERG protein to infer surface expression. We confirmed that LQT2 mutants expressed in HEK293 cells displayed a decreased surface density compared to WT hERG, and were differentially rescued by low temperature. However, we also uncovered some notable differences from the findings obtained via the biochemical approach. In particular, three mutations (N33T, R56Q, and A57P) with apparent WT-like hERG glycosylation patterns displayed up to 50% decreased surface expression. Furthermore, despite WT-like levels of complex glycosylation, these mutants have impaired forward trafficking, and exhibit varying half-lives at the cell surface. The results highlight utility of the surface labeling/flow cytometry approach to quantitatively assess trafficking deficiencies associated with LQT2 mutations, to discern underlying mechanisms, and to report on interventions that rescue deficits in hERG surface expression.
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Affiliation(s)
- Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, NY, United States
| | - Ananya Jain
- Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, NY, United States
| | - Henry M Colecraft
- Doctoral Program in Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, NY, United States.,Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, NY, United States.,Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, NY, United States
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Duensing TD, Watson SR. Assessment of Antibody-Dependent Cellular Cytotoxicity by Flow Cytometry. Cold Spring Harb Protoc 2018; 2018:2018/2/pdb.prot093815. [PMID: 29438058 DOI: 10.1101/pdb.prot093815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A useful feature of therapeutic antibodies is the ability to kill the cells to which they bind. Antibodies are capable of mediating cell killing in a variety of ways. Apoptosis, complement-mediated mechanisms, and antibody-dependent cellular cytotoxicity (ADCC) are all effects that can be assayed to characterize lead antibody candidates. Extensive, multidose characterizations of a series of candidates can be performed in a short amount of time using assays developed for high-throughput flow cytometry systems. Antibodies that contain the Fc portion of the human IgG1 can activate complement-mediated killing. In the ADCC method described here, cytotoxicity is mediated mostly by natural killer (NK) cells. Thus, if an antibody binds to its target on the surface of a tumor cell, Fc receptors on the surface of the NK cells (effector cells) recognize the bound antibody. This leads to the release of cytotoxic granules containing perforin, granzymes, and interferon γ, a cytokine that can stimulate other cells of the immune system such as T cells.
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Duensing TD, Watson SR. Complement-Dependent Cytotoxicity Assay. Cold Spring Harb Protoc 2018; 2018:2018/2/pdb.prot093799. [PMID: 29438057 DOI: 10.1101/pdb.prot093799] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A useful feature of therapeutic antibodies is the ability to kill the cells to which they bind. Antibodies are capable of mediating cell killing in a variety of ways. Apoptosis, complement-mediated mechanisms, and antibody-dependent cellular cytotoxicity are all effects that can be assayed to characterize lead antibody candidates. Extensive, multidose characterizations of a series of candidates can be performed in a short amount of time using assays developed for high-throughput flow cytometry systems. Antibodies that contain the Fc portion of the human IgG1 can activate complement-mediated cell death. One way in which they do this is via direct complement killing of tumor cells by the membrane attack complex, a process usually called complement-dependent cytotoxicity.
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Duensing TD, Watson SR. Assessment of Apoptosis (Programmed Cell Death) by Flow Cytometry. Cold Spring Harb Protoc 2018; 2018:2018/1/pdb.prot093807. [PMID: 29295901 DOI: 10.1101/pdb.prot093807] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A useful feature of therapeutic antibodies is the ability to kill the cells to which they bind. Antibodies are capable of mediating cell killing in a variety of ways. Apoptosis, complement-mediated mechanisms, and antibody-dependent cellular cytotoxicity are all effects that can be assayed to characterize lead antibody candidates. Extensive, multidose characterizations of a series of candidates can be performed in a short amount of time using assays developed for high-throughput flow cytometry systems. Here, we describe a simple multiplexed flow assay performed using Annexin V and propidium iodide that measures an early marker of apoptosis. When cells enter apoptosis, phosphatidyl serine (PS), which is normally found on the inside of the cytoplasmic membrane, is found on the extracellular surface of the membrane, thus revealing Annexin V-binding sites. Because binding of Annexin V to PS is calcium dependent, the buffers used for this assay must contain 1 mm calcium. The calcium dependence can also be used to test whether the Annexin V staining is specific. Thus, if the staining is performed in the presence of 1 mm EDTA, binding of Annexin V should be inhibited. The addition of propidium iodide allows subsequent stages of apoptosis and eventual cell death to be distinguished. For flow cytometry, this assay is best performed on suspension cells.
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