1
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Werth EG, Roos D, Philip ET. Immunocapture LC-MS methods for pharmacokinetics of large molecule drugs. Bioanalysis 2024; 16:165-177. [PMID: 38348660 DOI: 10.4155/bio-2023-0261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024] Open
Abstract
Implementation of immunocapture LC-MS methods to characterize the pharmacokinetic profile of large molecule drugs has become a widely used technique over the past decade. As the pharmaceutical industry strives for speediness into clinical development without jeopardizing quality, robust assays with generic application across the pipeline are becoming instrumental in bioanalysis, especially in early-stage development. This review highlights the capabilities and challenges involved in hybrid immunocapture LC-MS techniques and its continued applications in nonclinical and clinical pharmacokinetic assay design. This includes a comparison of LC-MS-based approaches to conventional ligand-binding assays and the driving demands in large molecule drug portfolios including growing sensitivity requirements and the unique challenges of new modalities requiring innovation in the bioanalytical laboratory.
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Affiliation(s)
- Emily G Werth
- Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT 06877, USA
| | - David Roos
- Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT 06877, USA
| | - Elsy T Philip
- Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT 06877, USA
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2
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Wong KS, Cheung HW, Choi YC, To NS, Wan TSM, Ho ENM. Screening and confirmation of recombinant human follistatin in equine plasma for doping control purposes. Drug Test Anal 2024; 16:259-267. [PMID: 37401514 DOI: 10.1002/dta.3540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 04/19/2023] [Accepted: 06/15/2023] [Indexed: 07/05/2023]
Abstract
Recombinant human follistatin (rhFST) is a potential performance-enhancing agent owing to its stimulating effect on muscle growth. Administration of rhFST to athletes is prohibited in human sports by the World Anti-Doping Agency (WADA) and in horseracing according to Article 6 of the International Agreement on Breeding, Racing and Wagering published by the International Federation of Horseracing Authorities (IFHA). For effective control of the potential misuse of rhFST in flat racing, methods for screening and confirmatory analysis are required. This paper describes the development and validation of a complete solution for detecting rhFST and confirming its presence in plasma samples collected from racehorses. A high-throughput analysis of rhFST with a commercially available enzyme-linked immunosorbent assay (ELISA) was evaluated for the screening of equine plasma samples. Any suspicious finding would then be subjected to a confirmatory analysis using immunocapture, followed by nano-liquid chromatography/high-resolution tandem mass spectrometry (nanoLC-MS/HRMS). The confirmation of rhFST by nanoLC-MS/HRMS was achieved by comparing the retention times and relative abundances of three characteristic product-ions with those from the reference standard in accordance with the industry criteria published by the Association of Official Racing Chemists. The two methods achieved comparable limit of detection (~2.5-5 ng/mL) and limit of confirmation (2.5 ng/mL or below), as well as adequate specificity, precision and reproducibility. To our knowledge, this is the first report of the screening and confirmation methods for rhFST in equine samples.
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Affiliation(s)
- Kin-Sing Wong
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Hiu Wing Cheung
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Yung-Ching Choi
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Ning-Sum To
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Terence S M Wan
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Emmie N M Ho
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
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3
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Dhenin J, Lafont V, Dupré M, Krick A, Mauriac C, Chamot-Rooke J. Monitoring mAb proteoforms in mouse plasma using an automated immunocapture combined with top-down and middle-down mass spectrometry. Proteomics 2024; 24:e2300069. [PMID: 37480175 DOI: 10.1002/pmic.202300069] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/27/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023]
Abstract
Monoclonal antibodies (mAbs) have established themselves as the leading biopharmaceutical therapeutic modality. Once the developability of a mAb drug candidate has been assessed, an important step is to check its in vivo stability through pharmacokinetics (PK) studies. The gold standard is ligand-binding assay (LBA) and liquid chromatography-mass spectrometry (LC-MS) performed at the peptide level (bottom-up approach). However, these analytical techniques do not allow to address the different mAb proteoforms that can arise from biotransformation. In recent years, top-down and middle-down mass spectrometry approaches have gained popularity to characterize proteins at the proteoform level but are not yet widely used for PK studies. We propose here a workflow based on an automated immunocapture followed by top-down and middle-down liquid chromatography-tandem mass spectrometry (LC-MS/MS) approaches to characterize mAb proteoforms spiked in mouse plasma. We demonstrate the applicability of our workflow on a large concentration range using pembrolizumab as a model. We also compare the performance of two state-of-the-art Orbitrap platforms (Tribrid Eclipse and Exploris 480) for these studies. The added value of our workflow for an accurate and sensitive characterization of mAb proteoforms in mouse plasma is highlighted.
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Affiliation(s)
- Jonathan Dhenin
- Institut Pasteur, Université Paris Cité, CNRS UAR2024, Mass Spectrometry for Biology, Paris, France
- Université Paris Cité, Sorbonne Paris Cité, Paris, France
- DMPK, Sanofi R&D, Chilly-Mazarin, France
| | | | | | | | | | - Julia Chamot-Rooke
- Institut Pasteur, Université Paris Cité, CNRS UAR2024, Mass Spectrometry for Biology, Paris, France
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4
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Massonnet P, Grifnée E, Farré-Segura J, Demeuse J, Huyghebaert L, Dubrowski T, Dufour P, Schoumacher M, Peeters S, Le Goff C, Cavalier E. Concise review on the combined use of immunocapture, mass spectrometry and liquid chromatography for clinical applications. Clin Chem Lab Med 2023; 61:1700-1707. [PMID: 37128992 DOI: 10.1515/cclm-2023-0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/21/2023] [Indexed: 05/03/2023]
Abstract
Immunocapture is now a well-established method for sample preparation prior to quantitation of peptides and proteins in complex matrices. This short review will give an overview of some clinical applications of immunocapture methods, as well as protocols with and without enzymatic digestion in a clinical context. The advantages and limitations of both approaches are discussed in detail. Challenges related to the choice of mass spectrometer are also discussed. Top-down, middle-down, and bottom-up approaches are discussed. Even though immunocapture has its limitations, its main advantage is that it provides an additional dimension of separation and/or isolation when working with peptides and proteins. Overall, this short review demonstrates the potential of such techniques in the field of proteomics-based clinical medicine and paves the way for better personalized medicine.
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Affiliation(s)
- Philippe Massonnet
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Elodie Grifnée
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Jordi Farré-Segura
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Justine Demeuse
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Loreen Huyghebaert
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Thomas Dubrowski
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Patrice Dufour
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | | | - Stéphanie Peeters
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
| | - Caroline Le Goff
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
| | - Etienne Cavalier
- Department of Clinical Chemistry, CHU de Liège, Centre de Recherche Intégré sur les Médicaments (CIRM), Liège, Belgium
- Clinical Chemistry, CIRM, University of Liège, Liège, Belgium
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5
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Völzke JL, Smatty S, Döring S, Ewald S, Oelze M, Fratzke F, Flemig S, Konthur Z, Weller MG. Efficient Purification of Polyhistidine-Tagged Recombinant Proteins Using Functionalized Corundum Particles. BioTech (Basel) 2023; 12:biotech12020031. [PMID: 37218748 DOI: 10.3390/biotech12020031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/24/2023] Open
Abstract
Immobilized metal affinity chromatography (IMAC) is a popular and valuable method for the affinity purification of polyhistidine-tagged recombinant proteins. However, it often shows practical limitations, which might require cumbersome optimizations, additional polishing, and enrichment steps. Here, we present functionalized corundum particles for the efficient, economical, and fast purification of recombinant proteins in a column-free format. The corundum surface is first derivatized with the amino silane APTES, then EDTA dianhydride, and subsequently loaded with nickel ions. The Kaiser test, well known in solid-phase peptide synthesis, was used to monitor amino silanization and the reaction with EDTA dianhydride. In addition, ICP-MS was performed to quantify the metal-binding capacity. His-tagged protein A/G (PAG), mixed with bovine serum albumin (BSA), was used as a test system. The PAG binding capacity was around 3 mg protein per gram of corundum or 2.4 mg per 1 mL of corundum suspension. Cytoplasm obtained from different E. coli strains was examined as examples of a complex matrix. The imidazole concentration was varied in the loading and washing buffers. As expected, higher imidazole concentrations during loading are usually beneficial when higher purities are desired. Even when higher sample volumes, such as one liter, were used, recombinant protein down to a concentration of 1 µg/mL could be isolated selectively. Comparing the corundum material with standard Ni-NTA agarose beads indicated higher purities of proteins isolated using corundum. His6-MBP-mSA2, a fusion protein consisting of monomeric streptavidin and maltose-binding protein in the cytoplasm of E. coli, was purified successfully. To show that this method is also suitable for mammalian cell culture supernatants, purification of the SARS-CoV-2-S-RBD-His8 expressed in human Expi293F cells was performed. The material cost of the nickel-loaded corundum material (without regeneration) is estimated to be less than 30 cents for 1 g of functionalized support or 10 cents per milligram of isolated protein. Another advantage of the novel system is the corundum particles' extremely high physical and chemical stability. The new material should be applicable in small laboratories and large-scale industrial applications. In summary, we could show that this new material is an efficient, robust, and cost-effective purification platform for the purification of His-tagged proteins, even in challenging, complex matrices and large sample volumes of low product concentration.
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Affiliation(s)
- Jule L Völzke
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Sarah Smatty
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Sarah Döring
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Shireen Ewald
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Marcus Oelze
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Franziska Fratzke
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Sabine Flemig
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Zoltán Konthur
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
| | - Michael G Weller
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489 Berlin, Germany
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Cunningham BR, Wharton RE, Lee C, Mojica MA, Krajewski LC, Gordon SC, Schaefer AM, Johnson RC, Hamelin EI. Measurement of Microcystin Activity in Human Plasma Using Immunocapture and Protein Phosphatase Inhibition Assay. Toxins (Basel) 2022; 14:toxins14110813. [PMID: 36422987 PMCID: PMC9697287 DOI: 10.3390/toxins14110813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/10/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
Microcystins are toxic chemicals generated by certain freshwater cyanobacteria. These chemicals can accumulate to dangerous levels during harmful algal blooms. When exposed to microcystins, humans are at risk of hepatic injury, including liver failure. Here, we describe a method to detect microcystins in human plasma by using immunocapture followed by a protein phosphatase inhibition assay. At least 279 microcystins have been identified, and most of these compounds share a common amino acid, the Adda side chain. We targeted this Adda side chain using a commercial antibody and extracted microcystins from human samples for screening and analysis. To quantitate the extracted microcystins, we fortified plasma with microcystin-LR, one of the most well-studied, commonly detected, and toxic microcystin congeners. The quantitation range for the detection of microcystin in human plasma using this method is 0.030-0.50 ng/mL microcystin-LR equivalents. This method detects unconjugated and conjugated forms (cysteine and glutathione) of microcystins. Quality control sample accuracies varied between 98.9% and 114%, with a precision of 7.18-15.8%. Finally, we evaluated plasma samples from a community health surveillance project of Florida residents living or working near harmful algae blooms.
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Affiliation(s)
- Brady R. Cunningham
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Rebekah E. Wharton
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Christine Lee
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Mike A. Mojica
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Logan C. Krajewski
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Shirley C. Gordon
- Christine E. Lynn College of Nursing, Florida Atlantic University, Boca Raton, FL 33431, USA
| | | | - Rudolph C. Johnson
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Elizabeth I. Hamelin
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
- Correspondence:
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7
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Pfeiffer A, Petersen JD, Falduto GH, Anderson DE, Zimmerberg J, Metcalfe DD, Olivera A. Selective immunocapture reveals neoplastic human mast cells secrete distinct microvesicle- and exosome-like populations of KIT-containing extracellular vesicles. J Extracell Vesicles 2022; 11:e12272. [PMID: 36239715 PMCID: PMC9838129 DOI: 10.1002/jev2.12272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 08/03/2022] [Accepted: 09/20/2022] [Indexed: 11/06/2022] Open
Abstract
Activating mutations in the receptor KIT promote the dysregulated proliferation of human mast cells (huMCs). The resulting neoplastic huMCs secrete extracellular vesicles (EVs) that can transfer oncogenic KIT among other cargo into recipient cells. Despite potential contributions to diseases, KIT-containing EVs have not been thoroughly investigated. Here, we isolated and characterized KIT-EV subpopulations released by neoplastic huMCs using an immunocapture approach that selectively isolates EVs containing KIT in its proper topology. Immunocapture of EVs on KIT antibody-coated electron microscopy (EM) affinity grids allowed to assess the morphology and size of KIT-EVs. Immunoblot analysis demonstrated KIT-EVs have a distinct protein profile from KIT-depleted EVs, contain exosome and microvesicle markers, and are separated into these subtypes by ultracentrifugation. Cell treatment with sphingomyelinase inhibitors shifted the protein content among KIT-EV subtypes, suggesting different biogenesis routes. Proteomic analysis revealed huMC KIT-EVs are enriched in proteins involved in signalling, immune responses, and cell migration, suggesting diverse biological functions, and indicated neoplastic huMCs disseminate KIT via shuttling in heterogeneous microvesicle- and exosome-like EVs. Further, selective KIT-immunocapture will enable the enrichment of specific huMC-derived EVs from complex human biosamples and facilitate an understanding of their in vivo functions and potential to serve as biomarkers of specific biological pathologies.
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Affiliation(s)
- Annika Pfeiffer
- Mast Cell Biology SectionLaboratory of Allergic DiseasesNational Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMarylandUSA
| | - Jennifer D. Petersen
- Section on Integrative BiophysicsDivision of Basic and Translational BiophysicsEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMarylandUSA
| | - Guido H. Falduto
- Mast Cell Biology SectionLaboratory of Allergic DiseasesNational Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMarylandUSA
| | - David Eric Anderson
- Advanced Mass Spectrometry Core FacilityNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMarylandUSA
| | - Joshua Zimmerberg
- Section on Integrative BiophysicsDivision of Basic and Translational BiophysicsEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMarylandUSA
| | - Dean D. Metcalfe
- Mast Cell Biology SectionLaboratory of Allergic DiseasesNational Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMarylandUSA
| | - Ana Olivera
- Mast Cell Biology SectionLaboratory of Allergic DiseasesNational Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMarylandUSA
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Wang H, Wu J, Pan P, Nguyen T, Cwik M, Morgan L. Novel sequential immunocapture microflow LC/MS/MS approach to measuring PTH-Fc protein in human serum. Bioanalysis 2021. [PMID: 34894717 DOI: 10.4155/bio-2021-0233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The quantitation of PTH-Fc in circulation by ligand binding assay presented a significant challenge due to the extremely low doses of administration, interference from the endogenous. A robust LC-MS/MS method to quantify the extremely low concentration of PTH-Fc in human serum utilized sequential immunoaffinity enrichment at PTH and Fc domains in conjunction with microflow LC-MS/MS technology significantly improved the sensitivity and selectivity. The assay displayed a quantitation range of 0.025-5.0 ng/ml and acceptable intraday and interday precision (%CV ≤ 15%) and accuracy (%bias ≤ ±15%) and can be routinely used for pharmacokinetic measurement of the drug. The novel sequential immunocapture workflow described herein can be applied to the quantitation of other recombinant therapeutic proteins to support clinical studies.
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Lefebvre D, Blanco-Valle K, Feraudet-Tarisse C, Merda D, Simon S, Fenaille F, Hennekinne JA, Nia Y, Becher F. Quantitative Determination of Staphylococcus aureus Enterotoxins Types A to I and Variants in Dairy Food Products by Multiplex Immuno-LC-MS/MS. J Agric Food Chem 2021; 69:2603-2610. [PMID: 33596646 DOI: 10.1021/acs.jafc.0c07545] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Staphylococcal enterotoxins (SEs) are responsible for frequent food poisoning outbreaks worldwide. Specific identification of SEs is crucial for confirmation of food poisoning, tracking of the incriminated foods or food ingredients, and removal from the food chain. Here, we report on a new food testing protocol addressing the challenge of low abundance of SEs in contaminated food and high sequence heterogeneity. Multiplex ability of targeted high-resolution mass spectrometry was succesfully applied to the simultaneous and quantitative determination of the eight most frequent SEs including sequence variants. In this aim, between three and eight proteotypic peptides of each SE were selected by carefully considering amino acid variations within each type, and sequence homology between types. Quantification of trace levels of SEs directly in food samples was reached by immunoaffinity enrichment and optimized analytical conditions. The assay was validated in dairy food products with a lower limit of quantification down to 0.1 ng/g (in milk), and quantification of SEs was successfully demonstrated in real-life samples collected during staphylococcal food poisoning outbreaks. Importantly, the ability of the method to detect diverse sequence variants was also illustrated. By enabling for the first time the simultaneous quantification of the eight most frequent SEs, the new mass spectrometry-based assay would facilitate the laboratory confirmation of positive samples in situation of food poisoning outbreaks.
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Affiliation(s)
- Donatien Lefebvre
- Département Médicaments et Technologies pour la Santé (DMTS), SPI, Université Paris-Saclay, CEA, INRAE, 91191 Gif-sur-Yvette, France
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, 94700 Maisons-Alfort, France
| | - Kevin Blanco-Valle
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, 94700 Maisons-Alfort, France
| | - Cécile Feraudet-Tarisse
- Département Médicaments et Technologies pour la Santé (DMTS), SPI, Université Paris-Saclay, CEA, INRAE, 91191 Gif-sur-Yvette, France
| | - Déborah Merda
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, 94700 Maisons-Alfort, France
| | - Stéphanie Simon
- Département Médicaments et Technologies pour la Santé (DMTS), SPI, Université Paris-Saclay, CEA, INRAE, 91191 Gif-sur-Yvette, France
| | - François Fenaille
- Département Médicaments et Technologies pour la Santé (DMTS), SPI, Université Paris-Saclay, CEA, INRAE, 91191 Gif-sur-Yvette, France
| | - Jacques-Antoine Hennekinne
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, 94700 Maisons-Alfort, France
| | - Yacine Nia
- Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université Paris-Est, 94700 Maisons-Alfort, France
| | - François Becher
- Département Médicaments et Technologies pour la Santé (DMTS), SPI, Université Paris-Saclay, CEA, INRAE, 91191 Gif-sur-Yvette, France
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10
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Wharton RE, Cunningham BR, Schaefer AM, Guldberg SM, Hamelin EI, Johnson RC. Measurement of Microcystin and Nodularin Activity in Human Urine by Immunocapture-Protein Phosphatase 2A Assay. Toxins (Basel) 2019; 11:E729. [PMID: 31847123 DOI: 10.3390/toxins11120729] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/06/2019] [Accepted: 12/11/2019] [Indexed: 12/14/2022] Open
Abstract
Microcystins (MC) and nodularin (NOD) are toxins released by cyanobacteria during harmful algal blooms. They are potent inhibitors of protein phosphatases 1 and 2A (PP1 and PP2A) and cause a variety of adverse symptoms in humans and animals if ingested. More than 250 chemically diverse congeners of MCs have been identified, but certified reference materials are only available for a few. A diagnostic test that does not require each reference material for detection is necessary to identify human exposures. To address this need, our lab has developed a method that uses an antibody to specifically isolate MCs and NOD from urine prior to detection via a commercially available PP2A kit. This assay quantitates the summed inhibitory activity of nearly all MCs and NOD on PP2A relative to a common MC congener, microcystin-LR (MC-LR). The quantitation range for MC-LR using this method is from 0.050–0.500 ng/mL. No background responses were detected in a convenience set of 50 individual urines. Interday and intraday % accuracies ranged from 94%–118% and relative standard deviations were 15% or less, meeting FDA guidelines for receptor binding assays. The assay detected low levels of MCs in urines from three individuals living in close proximity to harmful algal blooms (HABs) in Florida.
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Rifflet A, Filali S, Chenau J, Simon S, Fenaille F, Junot C, Carniel E, Becher F. Quantification of low abundance Yersinia pestis markers in dried blood spots by immuno-capture and quantitative high-resolution targeted mass spectrometry. Eur J Mass Spectrom (Chichester) 2019; 25:268-277. [PMID: 31096787 DOI: 10.1177/1469066718795978] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Plague, caused by the bacterium Yersinia pestis, is still present in several countries worldwide. Besides, Y. pestis has been designated as Tier 1 agent, the highest rank of bioterrorism agents. In this context, reliable diagnostic methods are of great importance. Here, we have developed an original workflow based upon dried blood spot for simplified sampling of clinical specimens, and specific immuno-mass spectrometry monitoring of Y. pestis biomarkers. Targeted proteins were selectively enriched from dried blood spot extracts by multiplex immunocapture using antibody-coated magnetic beads. After accelerated on-beads digestion, proteotypic peptides were monitored by multiplex LC-MS/MS through the parallel reaction monitoring mode. The DBS-IC-MS assay was designed to quantify both F1 and LcrV antigens, although 10-fold lower sensitivity was observed with LcrV. The assay was successfully validated for F1 with a lower limit of quantification at 5 ng·mL-1 in spiked blood, corresponding to only 0.1 ng on spots. In vivo quantification of F1 in blood and organ samples was demonstrated in the mouse model of pneumonic plague. The new assay could help to simplify the laboratory confirmation of positive point of care F1 dipstick.
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Affiliation(s)
- Aline Rifflet
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - Sofia Filali
- 2 Yersinia Research Unit, Institut Pasteur, Paris, France
| | - Jérôme Chenau
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - Stéphanie Simon
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - François Fenaille
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - Christophe Junot
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | | | - François Becher
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
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Zhang L, Wei Q, Han Q, Chen Q, Tai W, Zhang J, Song Y, Xia X. Detection of Shigella in Milk and Clinical Samples by Magnetic Immunocaptured-Loop-Mediated Isothermal Amplification Assay. Front Microbiol 2018; 9:94. [PMID: 29467730 PMCID: PMC5807921 DOI: 10.3389/fmicb.2018.00094] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 01/16/2018] [Indexed: 11/22/2022] Open
Abstract
Shigella is an important human food-borne zoonosis bacterial pathogen, and can cause clinically severe diarrhea. There is an urgent need to develop a specific, sensitive, and rapid methodology for detection of this pathogen. In this study, loop-mediated isothermal amplification (LAMP) combined with magnetic immunocapture assay (IC-LAMP) was first developed for the detection of Shigella in pure culture, artificial milk, and clinical stool samples. This method exhibited a detection limit of 8.7 CFU/mL. Compared with polymerase chain reaction, IC-LAMP is sensitive, specific, and reliable for monitoring Shigella. Additionally, IC-LAMP is more convenient, efficient, and rapid than ordinary LAMP, as it is more efficiently enriches pathogen cells without extraction of genomic DNA. Under isothermal conditions, the amplification curves and the green fluorescence were detected within 30 min in the presence of genomic DNA template. The overall analysis time was approximately 1 h, including the enrichment and lysis of the bacterial cells, a significantly short detection time. Therefore, the IC-LAMP methodology described here is potentially useful for the efficient detection of Shigella in various samples.
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Affiliation(s)
- Liding Zhang
- Molecular Medicine Research Center of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | | | - Qinqin Han
- Molecular Medicine Research Center of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Qiang Chen
- Molecular Medicine Research Center of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Wenlin Tai
- Yunnan Molecular Diagnosis Centre, The Second Affiliation Hospital of Kunming Medical University, Kunming, China
| | - Jinyang Zhang
- Molecular Medicine Research Center of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Yuzhu Song
- Molecular Medicine Research Center of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Xueshan Xia
- Molecular Medicine Research Center of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
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Korbakis D, Soosaipillai A, Diamandis EP. Study of kallikrein-related peptidase 6 (KLK6) and its complex with α1-antitrypsin in biological fluids. Clin Chem Lab Med 2017; 55:1385-1396. [PMID: 28672746 DOI: 10.1515/cclm-2017-0017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/27/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Human kallikrein-related peptidase 6 (KLK6) is a member of the kallikrein family of serine proteases. KLK6 is synthesized as a preproenzyme, mainly in tissues of the central nervous system (CNS), and secreted as an inactive precursor. Serum KLK6 is a biomarker of unfavorable prognosis for ovarian cancer, but its sensitivity for early detection is relatively low. Differential glycosylation of KLK6 has been identified in ascites fluid obtained from ovarian cancer patients, suggesting the presence of unique KLK6 isoforms in biological samples. METHODS In the present study, we applied a two-step enrichment approach for KLK6 in ovarian cancer ascites, followed by mice immunization and production of monoclonal antibodies. Immunoaffinity techniques coupled to mass spectrometric methods were employed for hybridoma screening and target antigen identification. RESULTS We found that the main target of the newly-generated monoclonal antibodies target was the serine protease inhibitor α1-antitrypsin (A1AT). Additional experiments confirmed that A1AT is the main inhibitor of KLK6 in biological fluids. One new antibody (24ED138) was chosen to build a hybrid assay for the accurate quantification of the A1AT-KLK6 complex in biological samples. The aforementioned assay was evaluated with serum samples collected from patients with ovarian cancer (n=24) and normal donors (n=16) and showed slight improvement in sensitivity (~12%) compared to the standard in-house KLK6 assay. CONCLUSIONS We conclude that KLK6 is present in biological fluids either as free form, or bound to A1AT, and the bound form performs better than total KLK6 as a biomarker of ovarian carcinoma.
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Fredolini C, Byström S, Pin E, Edfors F, Tamburro D, Iglesias MJ, Häggmark A, Hong MG, Uhlen M, Nilsson P, Schwenk JM. Immunocapture strategies in translational proteomics. Expert Rev Proteomics 2015; 13:83-98. [PMID: 26558424 PMCID: PMC4732419 DOI: 10.1586/14789450.2016.1111141] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aiming at clinical studies of human diseases, antibody-assisted assays have been applied to biomarker discovery and toward a streamlined translation from patient profiling to assays supporting personalized treatments. In recent years, integrated strategies to couple and combine antibodies with mass spectrometry-based proteomic efforts have emerged, allowing for novel possibilities in basic and clinical research. Described in this review are some of the field's current and emerging immunocapture approaches from an affinity proteomics perspective. Discussed are some of their advantages, pitfalls and opportunities for the next phase in clinical and translational proteomics.
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Affiliation(s)
- Claudia Fredolini
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Sanna Byström
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Elisa Pin
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Fredrik Edfors
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Davide Tamburro
- Department of Oncology-Pathology, Clinical Proteomics Mass Spectrometry, SciLifeLab, Karolinska Institutet, Solna, Sweden
| | - Maria Jesus Iglesias
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Anna Häggmark
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Mun-Gwan Hong
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Mathias Uhlen
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Peter Nilsson
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
| | - Jochen M Schwenk
- Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Solna, Sweden
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Franck T, Minguet G, Delporte C, Derochette S, Zouaoui Boudjeltia K, Van Antwerpen P, Gach O, Deby-Dupont G, Mouithys-Mickalad A, Serteyn D. An immunological method to combine the measurement of active and total myeloperoxidase on the same biological fluid, and its application in finding inhibitors which interact directly with the enzyme. Free Radic Res 2015; 49:790-9. [PMID: 25968947 DOI: 10.3109/10715762.2015.1027197] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Myeloperoxidase (MPO) is a pro-oxidant enzyme involved in inflammation, and the measurement of its activity in biological samples has emerged essential for laboratory and clinical investigations. We will describe a new method which combines the SIEFED (specific immunological extraction followed by enzymatic detection) and ELISA (ELISAcb) techniques to measure the active and total amounts of MPO on the same human sample and with the same calibration curve, as well as to define an accurate ratio between both the active and total forms of the enzyme. The SIEFED/ELISAcb method consists of the MPO extraction from aqueous or biological samples by immobilized anti-MPO antibodies coated onto microplate wells. After a washing step to eliminate unbound material, the activity of MPO is measured in situ by adding a reaction solution (SIEFED). Following aspiration of the reaction solution, a secondary anti-MPO antibody is added into the wells and the ELISAcb test is carried out in order to measure the total MPO content. To validate the combined method, a comparison was made with SIEFED and ELISA experiments performed separately on plasma samples isolated from human whole blood, after a neutrophil stimulation. The SIEFED/ELISAcb provides a suitable tool for the measurement of specific MPO activity in biological fluids and for the estimation of the inhibitory potential of a fluid. The method can also be used as a pharmacological tool to make the distinction between a catalytic inhibitor, which binds to MPO and inhibits its activity, and a steric inhibitor, which hinders the enzyme and prevents its immunodetection.
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Affiliation(s)
- T Franck
- Department of General Anaesthesia and Surgical Pathology of Large Animals, Faculty of Veterinary Medicine, B 41, University of Liege - Sart Tilman, Liège , Belgium
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Sanna G, Lecca V, Foddai A, Tola S. Development of a specific immunomagnetic capture-PCR for rapid detection of viable Mycoplasma agalactiae in sheep milk samples. J Appl Microbiol 2014; 117:1585-91. [PMID: 25272958 DOI: 10.1111/jam.12657] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/27/2014] [Accepted: 09/26/2014] [Indexed: 11/29/2022]
Abstract
AIMS To develop an immunomagnetic capture (IMC) to detect viable Mycoplasma agalactiae in routine ovine milk samples. METHODS AND RESULTS Polyclonal antibodies against two M. agalactiae membrane surface proteins (P80 and P55) were covalently conjugated to magnetic beads (MBs) to form MB-Ab80 and MB-Ab55. Mycoplasma agalactiae cells were captured by a specific antigen-antibody reaction and magnetic separation. Immunomagnetic capture (IMC) was used to isolate and concentrate M. agalactiae in serial decimal dilutions and in artificially contaminated milk to facilitate subsequent detection by PCR. A 375-bp fragment of M. agalactiae was amplified using a pair of M. agalactiae-specific primers in PCR. The limit of detection of IMC-PCR method ranged from 10 to 10(2) CCU ml(-1) when mycoplasmas were resuspended in PBS and from 10(2) to 10(3) CCU ml(-1) when mycoplasmas were resuspended in uncontaminated ovine milk. This study also describes the application of IMC-PCR method to test for M. agalactiae in 516 milk samples collected from sheep with suspected contagious agalactia. Its performance was evaluated relative to culture. CONCLUSIONS This report has demonstrated for the first time, the effective use of rapid and reliable IMC combined with PCR assay for the detection of viable M. agalactiae. SIGNIFICANCE AND IMPACT OF THE STUDY The method IMC-PCR provides an alternative to conventional microbiological detection, method and it could be applied to quick detection of M. agalactiae in routine sheep milk samples.
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Affiliation(s)
- G Sanna
- Istituto ZooprofilatticoSperimentale della Sardegna "G. Pegreffi", Sassari, Italy
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Tandon V, Zhang B, Radisic M, Murthy SK. Generation of tissue constructs for cardiovascular regenerative medicine: from cell procurement to scaffold design. Biotechnol Adv 2013; 31:722-35. [PMID: 22951918 PMCID: PMC3527695 DOI: 10.1016/j.biotechadv.2012.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 08/14/2012] [Accepted: 08/14/2012] [Indexed: 12/17/2022]
Abstract
The ability of the human body to naturally recover from coronary heart disease is limited because cardiac cells are terminally differentiated, have low proliferation rates, and low turn-over rates. Cardiovascular tissue engineering offers the potential for production of cardiac tissue ex vivo, but is currently limited by several challenges: (i) Tissue engineering constructs require pure populations of seed cells, (ii) Fabrication of 3-D geometrical structures with features of the same length scales that exist in native tissue is non-trivial, and (iii) Cells require stimulation from the appropriate biological, electrical and mechanical factors. In this review, we summarize the current state of microfluidic techniques for enrichment of subpopulations of cells required for cardiovascular tissue engineering, which offer unique advantages over traditional plating and FACS/MACS-based enrichment. We then summarize modern techniques for producing tissue engineering scaffolds that mimic native cardiac tissue.
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Affiliation(s)
- Vishal Tandon
- Department of Chemical Engineering, Northeastern University, 342 Snell Engineering Center, 360 Huntington Avenue, Boston, MA
| | - Boyang Zhang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, WB 368, Toronto, ON
| | - Milica Radisic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, WB 368, Toronto, ON
| | - Shashi K. Murthy
- Department of Chemical Engineering, Northeastern University, 342 Snell Engineering Center, 360 Huntington Avenue, Boston, MA
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Védy S, Valette M, Duchamp MB, Jacquemet C, Schillinger S, Perez P, Hollande A, Ragot C, Bakkouch S, Puyhardy JM. [Apport de l' immunocapture-Elisa au diagnostic de l'infection à virus grippal A(H1N1)pdm09 : une alternative à la RT-PCR ?]. Virologie (Montrouge) 2011; 15:205-208. [PMID: 36151660 DOI: 10.1684/vir.2011.17138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
AIM OF THE STUDY To evaluate immunocapture-Elisa (ICE) sensitivity versus RT-PCR in diagnosis of influenza A(H1N1)pdm09 virus infection. METHODS Sixty-seven RT-PCR-negative and 282 RT-PCR-positive nasopharyngeal swabs collected during winter 2009-2010 have been analyzed using ICE. RESULTS Among all the samples tested, a sensitivity of 31.3% was found for ICE. The sensitivity of ICE was directly correlated to the virus load determined through the number of cycling reactions necessary to reach detection by RT-PCR. CONCLUSION ICE can be a suitable method compared to RT-PCR when RT-PCR cannot be used for economical or epidemiological reasons. Its sensitivity is largely dependent of the nasopharyngeal sampling quality.
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Affiliation(s)
- Serge Védy
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Martine Valette
- Groupement hospitalier Est, Institut de microbiologie CNR du virus influenza pour la région Sud, 59, boulevard Pinel, 69677 Bron Cedex, France
| | - Maud Bouscambert Duchamp
- Groupement hospitalier Est, Institut de microbiologie CNR du virus influenza pour la région Sud, 59, boulevard Pinel, 69677 Bron Cedex, France
| | - Cyrielle Jacquemet
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Sarah Schillinger
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Pascale Perez
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Anne Hollande
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Céline Ragot
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Sylvie Bakkouch
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
| | - Jean-Michel Puyhardy
- HIA Legouest, Laboratoire de biologie médicale, 27, avenue de Plantières, BP 90001 57077 Metz Cedex 3, France
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El Alaoui S, Gresti C. Development of an immunocapture method for measuring IgA antibodies to tissue transglutaminase in the sera of patients with coeliac disease. Clin Exp Immunol 2006; 144:101-9. [PMID: 16542371 PMCID: PMC1809630 DOI: 10.1111/j.1365-2249.2006.03045.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2006] [Indexed: 11/26/2022] Open
Abstract
One of the most reliable sero-diagnostic tests for coeliac disease (CD) is the measurement, by ELISA, of serum IgA antibodies to tissue transglutaminase (tTG) adsorbed to the wells of microtitre plates. In spite of its reliability, however, some discrepancies exist with the results obtained by the antiendomysium histological assay (EMA) and by biopsy the accepted gold standard. Among the reasons for these differences in titres between the ELISA and the last 2 mentioned assays are the conformational changes that proteins undergo on adsorption and the importance of conformational epitopes on tTG for diagnosing CD. To address this problem, a novel procedure was developed using guinea-pig tTG (gptTG) free in solution to interact with IgA antibodies in the sera of CD patients. Any immune complexes so formed are then captured by anti-tTG antibodies preadsorbed to the wells of microtitre plates. This immunocapture method was optimized for the amount of soluble gptTG needed to interact with all the IgA's anti-tTG present in fixed dilutions of serum samples, the amount of rabbit IgG anti-gptTG used to coat the wells of microtitre plates and the order of addition of the reaction components. Comparison of the IgA titres obtained by immunocapture with those by EMA and ELISA (adsorbed tTG) on 9 highly positive and 6 weakly positive sera from clinically characterized CD patients and 5 negative sera from non-CD control subjects revealed that the IgA titres by the immunocapture procedure were well correlated with those obtained by EMA, whereas the titres on ELISA showed discrepancies with both immunocapture and EMA.
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