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The Biochemical Journal Feb 2019The immune system is capable of making antibodies against anything that is foreign, yet it does not react against components of self. In that sense, a fundamental... (Review)
Review
The immune system is capable of making antibodies against anything that is foreign, yet it does not react against components of self. In that sense, a fundamental requirement of the body's immune defense is specificity. Remarkably, this ability to specifically attack foreign antigens is directed even against antigens that have not been encountered a priori by the immune system. The specificity of an antibody for the foreign antigen evolves through an iterative process of somatic mutations followed by selection. There is, however, accumulating evidence that the antibodies are often functionally promiscuous or multi-specific which can lead to their binding to more than one antigen. An important cause of antibody cross-reactivity is molecular mimicry. Molecular mimicry has been implicated in the generation of autoimmune response. When foreign antigen shares similarity with the component of self, the antibodies generated could result in an autoimmune response. The focus of this review is to capture the contrast between specificity and promiscuity and the structural mechanisms employed by the antibodies to accomplish promiscuity, at the molecular level. The conundrum between the specificity of the immune system for foreign antigens on the one hand and the multi-reactivity of the antibody on the other has been addressed. Antibody specificity in the context of the rapid evolution of the antigenic determinants and molecular mimicry displayed by antigens are also discussed.
Topics: Animals; Antibodies; Antibody Specificity; Autoimmune Diseases; Cross Reactions; Humans; Molecular Mimicry
PubMed: 30723137
DOI: 10.1042/BCJ20180670 -
Journal of Molecular Recognition : JMR Nov 2014The concept of antibody specificity is analyzed and shown to reside in the ability of an antibody to discriminate between two antigens. Initially, antibody specificity... (Review)
Review
The concept of antibody specificity is analyzed and shown to reside in the ability of an antibody to discriminate between two antigens. Initially, antibody specificity was attributed to sequence differences in complementarity determining regions (CDRs), but as increasing numbers of crystallographic antibody-antigen complexes were elucidated, specificity was analyzed in terms of six antigen-binding regions (ABRs) that only roughly correspond to CDRs. It was found that each ABR differs significantly in its amino acid composition and tends to bind different types of amino acids at the surface of proteins. In spite of these differences, the combined preference of the six ABRs does not allow epitopes to be distinguished from the rest of the protein surface. These findings explain the poor success of past and newly proposed methods for predicting protein epitopes. Antibody polyspecificity refers to the ability of one antibody to bind a large variety of epitopes in different antigens, and this property explains how the immune system develops an antibody repertoire that is able to recognize every antigen the system is likely to encounter. Antibody heterospecificity arises when an antibody reacts better with another antigen than with the one used to raise the antibody. As a result, an antibody may sometimes appear to have been elicited by an antigen with which it is unable to react. The implications of antibody polyspecificity and heterospecificity in vaccine development are pointed out.
Topics: Animals; Antibodies; Antibody Specificity; Antigen-Antibody Complex; Complementarity Determining Regions; Humans
PubMed: 25277087
DOI: 10.1002/jmr.2394 -
PLoS Computational Biology May 2021Antibodies are widely used reagents to test for expression of proteins and other antigens. However, they might not always reliably produce results when they do not...
Antibodies are widely used reagents to test for expression of proteins and other antigens. However, they might not always reliably produce results when they do not specifically bind to the target proteins that their providers designed them for, leading to unreliable research results. While many proposals have been developed to deal with the problem of antibody specificity, it is still challenging to cover the millions of antibodies that are available to researchers. In this study, we investigate the feasibility of automatically generating alerts to users of problematic antibodies by extracting statements about antibody specificity reported in the literature. The extracted alerts can be used to construct an "Antibody Watch" knowledge base containing supporting statements of problematic antibodies. We developed a deep neural network system and tested its performance with a corpus of more than two thousand articles that reported uses of antibodies. We divided the problem into two tasks. Given an input article, the first task is to identify snippets about antibody specificity and classify if the snippets report that any antibody exhibits non-specificity, and thus is problematic. The second task is to link each of these snippets to one or more antibodies mentioned in the snippet. The experimental evaluation shows that our system can accurately perform the classification task with 0.925 weighted F1-score, linking with 0.962 accuracy, and 0.914 weighted F1 when combined to complete the joint task. We leveraged Research Resource Identifiers (RRID) to precisely identify antibodies linked to the extracted specificity snippets. The result shows that it is feasible to construct a reliable knowledge base about problematic antibodies by text mining.
Topics: Animals; Antibody Specificity; Data Mining; Humans; Mice; Neural Networks, Computer
PubMed: 34043624
DOI: 10.1371/journal.pcbi.1008967 -
Methods in Molecular Biology (Clifton,... 2023Monoclonal antibodies (MAbs) can be used to detect and quantify protein biomarker antigens (Ag). Systematic screening with an enzyme-linked immunosorbent assay (Butler,...
Monoclonal antibodies (MAbs) can be used to detect and quantify protein biomarker antigens (Ag). Systematic screening with an enzyme-linked immunosorbent assay (Butler, J Immunoass, 21(2-3):165-209, 2000) [1] can be used to identify matched Ab-Ag pairs. A method is described for identifying MAbs that recognize cardiac biomarker creatine kinase isoform MB. Cross-reactivity with skeletal muscle biomarker creatine kinase isoform MM and brain biomarker creatine kinase isoform BB is also examined.
Topics: Antibody Specificity; Enzyme-Linked Immunosorbent Assay; Creatine Kinase; Antibodies, Monoclonal; Muscle, Skeletal; Sensitivity and Specificity
PubMed: 36795358
DOI: 10.1007/978-1-0716-2903-1_4 -
Methods in Molecular Biology (Clifton,... 2018Antibodies are the most widely used reagent for isolation and detection of specific proteins. However, using antibodies that are not highly specific in these studies can...
Antibodies are the most widely used reagent for isolation and detection of specific proteins. However, using antibodies that are not highly specific in these studies can generate inaccurate and misleading data. Protein microarrays offer a platform by which antibody cross-reactivity against a broad range of cellular antigens can be simultaneously and quantitatively profiled. This protocol describes in detail the process of array pretreatment, antibody binding, washing, scanning and quantitative analysis of antibody specificity.
Topics: Animals; Antibodies; Antibody Specificity; Antigens; Humans; Protein Array Analysis; Proteomics
PubMed: 29714021
DOI: 10.1007/978-1-4939-7841-0_14 -
Current Protocols in Immunology Aug 2015This unit describes six different ELISA systems for the detection of specific antibodies, soluble antigens, or cell-surface antigens. In all six systems, soluble...
This unit describes six different ELISA systems for the detection of specific antibodies, soluble antigens, or cell-surface antigens. In all six systems, soluble reactants are removed from solution after specifically binding to solid-phase reactants. In the first four protocols, solid-phase reactants are prepared by adsorbing an antigen or antibody onto plastic microtiter plates; in the next two protocols, the solid-phase reactants are cell-associated molecules. In all protocols, the solid-phase reagents are incubated with secondary or tertiary reactants covalently coupled to an enzyme. Unbound conjugates are washed out and a chromogenic or fluorogenic substrate is added. As the substrate is hydrolyzed by the bound enzyme conjugate, a colored or fluorescent product is generated. Finally, the product is detected visually or with a microtiter plate reader. The amount of product generated is proportional to the amount of analysate in the test mixture. One of the support protocols can be used to optimize the different ELISAs. A second support protocol presents a method for preparing alkaline phosphatase conjugates.
Topics: Antibodies; Antibody Specificity; Antigens; Enzyme-Linked Immunosorbent Assay; Epitopes; Protein Binding
PubMed: 26237010
DOI: 10.1002/0471142735.im0201s110 -
Frontiers in Immunology 2020Monoclonal antibodies (mAbs) have become one of the most important classes of biopharmaceutical products, and they continue to dominate the universe of biopharmaceutical... (Review)
Review
Monoclonal antibodies (mAbs) have become one of the most important classes of biopharmaceutical products, and they continue to dominate the universe of biopharmaceutical markets in terms of approval and sales. They are the most profitable single product class, where they represent six of the top ten selling drugs. At the beginning of the 1990s, an antibody selection technology known as antibody phage display was developed by John McCafferty and Sir. Gregory Winter that enabled the discovery of human antibodies for diverse applications, particularly antibody-based drugs. They created combinatorial antibody libraries on filamentous phage to be utilized for generating antigen specific antibodies in a matter of weeks. Since then, more than 70 phage-derived antibodies entered clinical studies and 14 of them have been approved. These antibodies are indicated for cancer, and non-cancer medical conditions, such as inflammatory, optical, infectious, or immunological diseases. This review will illustrate the utility of phage display as a powerful platform for therapeutic antibodies discovery and describe in detail all the approved mAbs derived from phage display.
Topics: Animals; Antibodies, Monoclonal; Antibody Specificity; Antineoplastic Agents, Immunological; Cell Surface Display Techniques; Clinical Trials as Topic; Drug Development; Drug Evaluation, Preclinical; Genetic Engineering; High-Throughput Screening Assays; Humans; Molecular Targeted Therapy; Translational Research, Biomedical; Treatment Outcome
PubMed: 32983137
DOI: 10.3389/fimmu.2020.01986 -
Current Topics in Microbiology and... 2001
Review
Topics: Animals; Antibody Affinity; Antibody Specificity; Antigen-Antibody Reactions; Binding Sites; Humans
PubMed: 11443882
DOI: 10.1007/978-3-662-05783-4_5 -
Toxins Dec 2023To achieve accurate detection of AFB1 toxin content in agricultural products and avoid false-positive rates in the assays, the specificity of mAbs is critical. We...
Production of AFB1 High-Specificity Monoclonal Antibody by Three-Stage Screening Combined with the De-Homologation of Antibodies and the Development of High-Throughput icELISA.
To achieve accurate detection of AFB1 toxin content in agricultural products and avoid false-positive rates in the assays, the specificity of mAbs is critical. We improved the specificity of the prepared monoclonal antibodies by modifying the traditional limiting dilution subcloning method. The traditional finite dilution method was modified with three-stage screening (the trending concentration of standards used in the screening is low-high-low) to achieve high specificity in pre-cell screening and increased the number of subclones to 10 to achieve the de-homologation of antibodies. A modified limiting dilution obtained a highly specific AFB1 monoclonal cell line, ZFG8, with a 50% inhibition concentration (IC50) of 0.3162 ng/mL. Notably, it exhibited the highest specificity compared to anti-AFB1 monoclonal antibodies prepared by other investigators. The maximum cross-reactivity of the mAb with structural analogues for AFB2, AFG1, AFG2, and AFM1 was 0.34%. The results showed that this type of screening improves the monoclonal antibodies' specificity. Based on this ZFG8 monoclonal antibody, an icELISA assay was established with an IC50 of 0.2135 ng/mL for AFB1. The limit of the linear detection range of icELISA is 0.0422-1.29267 ng/mL with reasonable specificity and precision. The recoveries of AFB1 in samples of corn flour and wheat meal ranged from 84 to 107%, with CVs below 9.3%. The recoveries of structural analogues (AFB2, AFM1, AFG1, and AFG2) were less than 10% in both corn flour and wheat meal. The results showed that the prepared AFB1 monoclonal antibody could accurately and specifically recognize AFB1 residues in agricultural products while ignoring the effects of other structural analogues.
Topics: Antibodies, Monoclonal; Agriculture; Antibody Specificity; Biological Assay; Cell Line; Starch
PubMed: 38251228
DOI: 10.3390/toxins16010011 -
Nature Methods Dec 2018
Topics: Antibodies; Antibody Specificity
PubMed: 30504880
DOI: 10.1038/s41592-018-0248-z