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Journal of Natural Medicines Jan 2018Immunoassays are antibody-based analytical methods for quantitative/qualitative analysis. Since the principle of immunoassays is based on specific antigen-antibody... (Review)
Review
Immunoassays are antibody-based analytical methods for quantitative/qualitative analysis. Since the principle of immunoassays is based on specific antigen-antibody reaction, the assays have been utilized worldwide for diagnosis, pharmacokinetic studies by drug monitoring, and the quality control of commercially available products. Berson and Yalow were the first to develop an immunoassay, known as radioimmunoassay (RIA), for detecting endogenous plasma insulin [1], a development for which Yalow was awarded the Nobel Prize in Physiology or Medicine in 1977. Even today, after half a century, immunoassays are widely utilized with some modifications from the originally proposed system, e.g., radioisotopes have been replaced with enzymes because of safety concerns regarding the use of radioactivity, which is referred to as enzyme immunoassay/enzyme-linked immunosorbent assay (ELISA). In addition, progress has been made in ELISA with the recent advances in recombinant DNA technology, leading to increase in the range of antibodies, probes, and even systems. This review article describes ELISA and its applications for the detection of plant secondary metabolites.
Topics: Enzyme-Linked Immunosorbent Assay; Haptens; Humans; Immunoassay
PubMed: 29164507
DOI: 10.1007/s11418-017-1144-z -
Toxins Mar 2022Appropriate hapten design and synthesis have been identified as critical steps to generate high-performance immunoreagents and to develop sensitive and selective...
Appropriate hapten design and synthesis have been identified as critical steps to generate high-performance immunoreagents and to develop sensitive and selective immunoanalytical methods. Antibodies and immunoassays for the major mycotoxin zearalenone have been reported and marketed. However, zearalenone haptens have mostly been prepared by the oxime active ester technique, and hapten characterization has generally been poor or non-existent. In the present study, novel haptens of zearalenone with longer linkers and with alternative tethering sites have been designed for immunizing and assay conjugate preparation. All of these molecules were purified and spectroscopically verified, and a structure-activity relationship evaluation was carried out. This approach revealed that the hapten with the linker at the carbonyl group generated antibodies with a higher affinity than the hapten functionalized at the phenyl moiety. Antibodies produced with the latter hapten, on the other hand, showed lower cross-reactivity values to the major zearalenone metabolites. Finally, similar immunoassay sensitivity was achieved with all of the antibodies when heterologous haptens were employed. Furthermore, by altering the structure of the competing antigen, the immunoassay selectivity was modified. These results demonstrate that immunochemical methods for zearalenone rapid analysis can still be improved in terms of sensitivity and selectivity.
Topics: Antibodies; Antigens; Enzyme-Linked Immunosorbent Assay; Haptens; Immunoassay; Zearalenone
PubMed: 35324682
DOI: 10.3390/toxins14030185 -
Allergy Feb 2022Drug hypersensitivity reactions (DHR) are heterogeneous and unusual immune reactions with rather unique clinical presentations. Accumulating evidence indicates that... (Review)
Review
Drug hypersensitivity reactions (DHR) are heterogeneous and unusual immune reactions with rather unique clinical presentations. Accumulating evidence indicates that certain non-covalent drug-protein interactions are able to elicit exclusively effector functions of antibody reactions or complete T-cell reactions which contribute substantially to DHR. Here, we discuss three key interactions; (a) mimicry: whereby soluble, non-covalent drug-protein complexes ("fake antigens") mimic covalent drug-protein adducts; (b) increased antibody affinity: for example, in quinine-type immune thrombocytopenia where the drug gets trapped between antibody and membrane-bound glycoprotein; and (c) p-i-stimulation: where naïve and memory T cells are activated by direct binding of drugs to the human leukocyte antigen and/or T-cell receptors. This transient drug-immune receptor interaction initiates a polyclonal T-cell response with mild-to-severe DHR symptoms. Notable complications arising from p-i DHR can include viral reactivations, autoimmunity, and multiple drug hypersensitivity. In conclusion, DHR is characterized by abnormal immune stimulation driven by non-covalent drug-protein interactions. This contrasts DHR from "normal" immunity, which relies on antigen-formation by covalent hapten-protein adducts and predominantly results in asymptomatic immunity.
Topics: Drug Hypersensitivity; HLA Antigens; Haptens; Humans; Receptors, Antigen, T-Cell; Receptors, Immunologic
PubMed: 34037262
DOI: 10.1111/all.14962 -
Biomolecules Jul 2020Fluoroacetamide (FAM) is a small (77 Da) and highly toxic chemical, formerly used as a rodenticide and potentially as a poison by terrorists. Poisoning with FAM has...
Fluoroacetamide (FAM) is a small (77 Da) and highly toxic chemical, formerly used as a rodenticide and potentially as a poison by terrorists. Poisoning with FAM has occurred in humans, but few reliably rapid detection methods and antidotes have been reported. Therefore, producing a specific antibody to FAM is not only critical for the development of a fast diagnostic but also a potential treatment. However, achieving this goal is a great challenge, mainly due to the very low molecular weight of FAM. Here, we design two groups of FAM haptens for the first time, maximally exposing the fluorine or amino groups, with the aid of linear aliphatic or phenyl-contained spacer arms. Interestingly, whereas the hapten with fluorine at the far end of the hapten did not induce an antibody response to FAM, the hapten with an amino group at the far end and phenyl-contained spacer arm triggered a significantly specific antibody response. Finally, a monoclonal antibody (mAb) named 5D11 was successfully obtained with an IC value of 97 μg mL and negligible cross-reactivities to the other nine functional and structural analogs.
Topics: Animals; Antibodies, Monoclonal; Fluoroacetates; Haptens; Immunization; Inhibitory Concentration 50; Mice; Mice, Inbred BALB C; Molecular Structure; Spleen
PubMed: 32630260
DOI: 10.3390/biom10070986 -
Pharmacological Reviews Jul 2017Substance use disorder, especially in relation to opioids such as heroin and fentanyl, is a significant public health issue and has intensified in recent years. As a... (Review)
Review
Substance use disorder, especially in relation to opioids such as heroin and fentanyl, is a significant public health issue and has intensified in recent years. As a result, substantial interest exists in developing therapeutics to counteract the effects of abused drugs. A promising universal strategy for antagonizing the pharmacology of virtually any drug involves the development of a conjugate vaccine, wherein a hapten structurally similar to the target drug is conjugated to an immunogenic carrier protein. When formulated with adjuvants and immunized, the immunoconjugate should elicit serum IgG antibodies with the ability to sequester the target drug to prevent its entry to the brain, thereby acting as an immunoantagonist. Despite the failures of first-generation conjugate vaccines against cocaine and nicotine in clinical trials, second-generation vaccines have shown dramatically improved performance in preclinical models, thus renewing the potential clinical utility of conjugate vaccines in curbing substance use disorder. This review explores the critical design elements of drug conjugate vaccines such as hapten structure, adjuvant formulation, bioconjugate chemistry, and carrier protein selection. Methods for evaluating these vaccines are discussed, and recent progress in vaccine development for each drug is summarized.
Topics: Animals; Drug Antagonism; Haptens; Humans; Illicit Drugs; Substance-Related Disorders; Vaccines, Conjugate
PubMed: 28634286
DOI: 10.1124/pr.117.013904 -
Journal of Immunology Research 2014Haptens are small molecule irritants that bind to proteins and elicit an immune response. Haptens have been commonly used to study allergic contact dermatitis (ACD)... (Review)
Review
Haptens are small molecule irritants that bind to proteins and elicit an immune response. Haptens have been commonly used to study allergic contact dermatitis (ACD) using animal contact hypersensitivity (CHS) models. However, extensive research into contact hypersensitivity has offered a confusing and intriguing mechanism of allergic reactions occurring in the skin. The abilities of haptens to induce such reactions have been frequently utilized to study the mechanisms of inflammatory bowel disease (IBD) to induce autoimmune-like responses such as autoimmune hemolytic anemia and to elicit viral wart and tumor regression. Hapten-induced tumor regression has been studied since the mid-1900s and relies on four major concepts: (1) ex vivo haptenation, (2) in situ haptenation, (3) epifocal hapten application, and (4) antigen-hapten conjugate injection. Each of these approaches elicits unique responses in mice and humans. The present review attempts to provide a critical appraisal of the hapten-mediated tumor treatments and offers insights for future development of the field.
Topics: Animals; Antigens; Antineoplastic Agents; Autoimmunity; Cytokines; Dermatitis, Allergic Contact; Haptens; Humans; Immunoconjugates; Immunoglobulin M; Mice; Neoplasms; Skin; T-Lymphocytes; Tumor Burden
PubMed: 24949488
DOI: 10.1155/2014/175265 -
Immunological Reviews Mar 2016Hapten-binding antibodies have for more than 50 years played a pivotal role in immunology, paving the way to antibody generation (as haptens are very important and... (Review)
Review
Hapten-binding antibodies have for more than 50 years played a pivotal role in immunology, paving the way to antibody generation (as haptens are very important and robust immunogens), to antibody characterization (as the first structures generated more than 40 years ago were those of hapten binders), and enabled and expanded antibody engineering technologies. The latter field of engineered antibodies evolved over many years and many steps resulting in recombinant humanized or human-derived antibody derivatives in multiple formats. Today, hapten-binding antibodies are applied not only as reagents and tools (where they still play an important part) but evolved also to engineered targeting and pretargeting vehicles for disease diagnosis and therapy. Here we describe recent applications of hapten-binding antibodies and of engineered mono- and bispecific hapten-binding antibody derivatives. We have designed and applied these molecules for the modulation of the pharmacokinetic properties of small compounds or peptides. They are also integrated as additional binding entities into bispecific antibody formats. Here they serve as non-covalent or covalent coupling modules to haptenylated compounds, to enable targeted payload delivery to disease tissues or cells.
Topics: Animals; Antibodies, Bispecific; Antigens, Surface; Biomarkers; Drug Delivery Systems; Haptens; Humans; Immunoglobulin G; Molecular Targeted Therapy; Protein Binding; Protein Engineering; Recombinant Fusion Proteins
PubMed: 26864111
DOI: 10.1111/imr.12386 -
Chembiochem : a European Journal of... Aug 2022Stimulation of the body's immune system toward tumor cells is now well recognized as a promising strategy in cancer therapy. Just behind cell therapy and monoclonal...
Stimulation of the body's immune system toward tumor cells is now well recognized as a promising strategy in cancer therapy. Just behind cell therapy and monoclonal antibodies, small molecule-based strategies are receiving growing attention as alternatives to direct immune response against tumor cells. However, the development of small-molecule approaches to modulate the balance between stimulatory immune factors and suppressive factors in a targeted way remains a challenge. Here, we report the cell surface functionalization of LS174T cancer cells with an abiotic hapten to recruit antibodies to the cell surface. Metabolic glycoengineering followed by covalent reaction with the hapten results in antibody recognition of the target cells. Microscopy and flow cytometry studies provide compelling evidence that metabolic glycoengineering and small molecule stimulators can be combined to direct antibody recognition.
Topics: Antibodies, Monoclonal; Haptens; Neoplasms; Polysaccharides
PubMed: 35638149
DOI: 10.1002/cbic.202200125 -
Hematology/oncology Clinics of North... Aug 2007Drug-induced thrombocytopenia (DIT) is a relatively common clinical disorder. It is imperative to provide rapid identification and removal of the offending agent before... (Review)
Review
Drug-induced thrombocytopenia (DIT) is a relatively common clinical disorder. It is imperative to provide rapid identification and removal of the offending agent before clinically significant bleeding or, in the case of heparin, thrombosis occurs. DIT can be distinguished from idiopathic thrombocytopenic purpura, a bleeding disorder caused by thrombocytopenia not associated with a systemic disease, based on the history of drug ingestion or injection and laboratory findings. DIT disorders can be a consequence of decreased platelet production (bone marrow suppression) or accelerated platelet destruction (especially immune-mediated destruction).
Topics: Antibodies; Antibody Formation; Drug-Related Side Effects and Adverse Reactions; Haptens; Humans; Thrombocytopenia
PubMed: 17666285
DOI: 10.1016/j.hoc.2007.06.005 -
BMB Reports Mar 2014The combination of a high-affinity antibody to a hapten, and hapten-conjugated compounds, can provide an alternative to the direct chemical cross-linking of the antibody... (Review)
Review
The combination of a high-affinity antibody to a hapten, and hapten-conjugated compounds, can provide an alternative to the direct chemical cross-linking of the antibody and compounds. An optimal hapten for in vitro use is one that is absent in biological systems. For in vivo applications, additional characteristics such as pharmacological safety and physiological inertness would be beneficial. Additionally, methods for cross-linking the hapten to various chemical compounds should be available. Cotinine, a major metabolite of nicotine, is considered advantageous in these aspects. A high-affinity anti-cotinine recombinant antibody has recently become available, and can be converted into various formats, including a bispecific antibody. The bispecific anti-cotinine antibody was successfully applied to immunoblot, enzyme immunoassay, immunoaffinity purification, and pre-targeted in vivo radioimmunoimaging. The anti-cotinine IgG molecule could be complexed with aptamers to form a novel affinity unit, and extended the in vivo half-life of aptamers, opening up the possibility of applying the same strategy to therapeutic peptides and chemical compounds.
Topics: Animals; Antibodies; Antigen-Antibody Complex; Aptamers, Peptide; Cotinine; Haptens; Humans; Immunoconjugates; Radioimmunodetection
PubMed: 24499668
DOI: 10.5483/bmbrep.2014.47.3.006