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| 2. |
- Ayoglu, Burcu, et al.
(författare)
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Affinity proteomics within rare diseases : a BIO-NMD study for blood biomarkers of muscular dystrophies
- 2014
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Ingår i: EMBO Molecular Medicine. - : EMBO. - 1757-4676 .- 1757-4684. ; 6:7, s. 918-936
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Tidskriftsartikel (refereegranskat)abstract
- Despite the recent progress in the broad-scaled analysis of proteins in body fluids, there is still a lack in protein profiling approaches for biomarkers of rare diseases. Scarcity of samples is the main obstacle hindering attempts to apply discovery driven protein profiling in rare diseases. We addressed this challenge by combining samples collected within the BIO-NMD consortium from four geographically dispersed clinical sites to identify protein markers associated with muscular dystrophy using an antibody bead array platform with 384 antibodies. Based on concordance in statistical significance and confirmatory results obtained from analysis of both serum and plasma, we identified eleven proteins associated with muscular dystrophy, among which four proteins were elevated in blood from muscular dystrophy patients: carbonic anhydrase III (CA3) and myosin light chain 3 (MYL3), both specifically expressed in slow-twitch muscle fibers and mitochondrial malate dehydrogenase 2 (MDH2) and electron transfer flavo-protein A (ETFA). Using age-matched sub-cohorts, 9 protein profiles correlating with disease progression and severity were identified, which hold promise for the development of new clinical tools for management of dystrophinopathies.
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| 4. |
- Ayoglu, Burcu, et al.
(författare)
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Anoctamin 2 identified as an autoimmune target in multiple sclerosis
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences of the USA. - 0027-8424 .- 1091-6490. ; 113:8, s. 2188-2193
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Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system and also is regarded as an autoimmune condition. However, the antigenic targets of the autoimmune response in MS have not yet been deciphered. In an effort to mine the autoantibody repertoire within MS, we profiled 2,169 plasma samples from MS cases and population-based controls using bead arrays built with 384 human protein fragments selected from an initial screening with 11,520 antigens. Our data revealed prominently increased autoantibody reactivity against the chloride-channel protein anoctamin 2 (ANO2) in MS cases compared with controls. This finding was corroborated in independent assays with alternative protein constructs and by epitope mapping with peptides covering the identified region of ANO2. Additionally, we found a strong interaction between the presence of ANO2 autoantibodies and the HLA complex MS-associated DRB1*15 allele, reinforcing a potential role for ANO2 autoreactivity in MS etiopathogenesis. Furthermore, immunofluorescence analysis in human MS brain tissue showed ANO2 expression as small cellular aggregates near and inside MS lesions. Thus this study represents one of the largest efforts to characterize the autoantibody repertoire within MS. The findings presented here demonstrate that an ANO2 autoimmune subphenotype may exist in MS and lay the groundwork for further studies focusing on the pathogenic role of ANO2 autoantibodies in MS.
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| 6. |
- Ayoglu, Burcu, et al.
(författare)
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Antigen arrays for profiling autoantibody repertoires
- 2016
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Ingår i: Bioanalysis. - : FUTURE SCI LTD. - 1757-6180 .- 1757-6199. ; 8:10, s. 1105-1126
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Forskningsöversikt (refereegranskat)abstract
- Autoantibodies are a key component for the diagnosis, prognosis and monitoring of various diseases. In order to discover novel autoantibody targets, highly multiplexed assays based on antigen arrays hold a great potential and provide possibilities to analyze hundreds of body fluid samples for their reactivity pattern against thousands of antigens in parallel. Here, we provide an overview of the available technologies for producing antigen arrays, highlight some of the technical and methodological considerations and discuss their applications as discovery tools. Together with recent studies utilizing antigen arrays, we give an overview on how the different types of antigen arrays have and will continue to deliver novel insights into autoimmune diseases among several others.
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| 7. |
- Ayoglu, Burcu, et al.
(författare)
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Autoantibody profiling in multiple sclerosis using arrays of human protein fragments
- 2013
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 12:9, s. 2657-2672
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Tidskriftsartikel (refereegranskat)abstract
- Profiling the autoantibody repertoire with large antigen collections is emerging as a powerful tool for the identification of biomarkers for autoimmune diseases. Here, a systematic and undirected approach was taken to screen for profiles of IgG in human plasma from 90 individuals with multiple sclerosis related diagnoses. Reactivity pattern of 11,520 protein fragments (representing ̃38% of all human protein encoding genes) were generated on planar protein microarrays built within the Human Protein Atlas. For more than 2,000 antigens IgG reactivity was observed, among which 64% were found only in single individuals. We used reactivity distributions among multiple sclerosis subgroups to select 384 antigens, which were then reevaluated on planar microarrays, corroborated with suspension bead arrays in a larger cohort (n = 376) and confirmed for specificity in inhibition assays. Among the heterogeneous pattern within and across multiple sclerosis subtypes, differences in recognition frequencies were found for 51 antigens, which were enriched for proteins of transcriptional regulation. In conclusion, using protein fragments and complementary high-throughput protein array platforms facilitated an alternative route to discovery and verification of potentially disease-associated autoimmunity signatures, that are now proposed as additional antigens for large-scale validation studies across multiple sclerosis biobanks.
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| 8. |
- Ayoglu, Burcu, et al.
(författare)
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Bead Arrays for Antibody and Complement Profiling Reveal Joint Contribution of Antibody Isotypes to C3 Deposition
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:5, s. e96403-
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Tidskriftsartikel (refereegranskat)abstract
- The development of antigen arrays has provided researchers with great tools to identify reactivities against self or foreign antigens from body fluids. Yet, these approaches mostly do not address antibody isotypes and their effector functions even though these are key points for a more detailed understanding of disease processes. Here, we present a bead array-based assay for a multiplexed determination of antigen-specific antibody levels in parallel with their properties for complement activation. We measured the deposition of C3 fragments from serum samples to reflect the degree of complement activation via all three complement activation pathways. We utilized the assay on a bead array containing native and citrullinated peptide antigens to investigate the levels of IgG, IgM and IgA autoantibodies along with their complement activating properties in serum samples of 41 rheumatoid arthritis patients and 40 controls. Our analysis revealed significantly higher IgG reactivity against the citrullinated fibrinogen beta and filaggrin peptides as well as an IgA reactivity that was exclusive for citrullinated fibrinogen b peptide and C3 deposition in rheumatoid arthritis patients. In addition, we characterized the humoral immune response against the viral EBNA-1 antigen to demonstrate the applicability of this assay beyond autoimmune conditions. We observed that particular buffer compositions were demanded for separate measurement of antibody reactivity and complement activation, as detection of antigen-antibody complexes appeared to be masked due to C3 deposition. We also found that rheumatoid factors of IgM isotype altered C3 deposition and introduced false-positive reactivities against EBNA-1 antigen. In conclusion, the presented bead-based assay setup can be utilized to profile antibody reactivities and immune-complex induced complement activation in a high-throughput manner and could facilitate the understanding and diagnosis of several diseases where complement activation plays role in the pathomechanism.
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| 9. |
- Ayoglu, Burcu, et al.
(författare)
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Multiplexed antigen bead arrays for the assessment of antibody selectivity and epitope mapping
- 2018
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Ingår i: Epitope Mapping Protocols. - New York, NY : Humana Press Inc.. ; , s. 239-248
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Bokkapitel (refereegranskat)abstract
- With the increasing number of binding reagents for affinity-based investigations of the human proteome, high-throughput tools for the characterization of the used reagents become essential. For the analysis of binding selectivity, bead-based antigen arrays offer a miniaturized and parallelized assay platform to meet such needs, as they enable two-dimensional multiplexing to analyze up to 384 samples against up to 500 analytes in a single round of analysis. In this chapter, we describe our protocols for the generation of multiplex bead arrays built on immobilized protein fragments, as well as biotinylated peptides. Combined together, these two versions of antigen arrays offer a versatile approach for multiplexed characterization of antibody binding selectivity, off-target interactions, as well as mapping for the amino acids of epitopes involved in antibody binding.
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| 10. |
- Ayoglu, Burcu, et al.
(författare)
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Multiplexed protein profiling by sequential affinity capture
- 2016
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Ingår i: Proteomics. - : Wiley-Blackwell. - 1615-9853 .- 1615-9861. ; 16:8, s. 1251-1256
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Tidskriftsartikel (refereegranskat)abstract
- Antibody microarrays enable parallelized and miniaturized analysis of clinical samples, and have proven to provide novel insights for the analysis of different proteomes. However, there are concerns that the performance of such direct labeling and single antibody assays are prone to off-target binding due to the sample context. To improve selectivity and sensitivity while maintaining the possibility to conduct multiplexed protein profiling, we developed a multiplexed and semi-automated sequential capture assay. This novel bead-based procedure encompasses a first antigen capture, labeling of captured protein targets on magnetic particles, combinatorial target elution and a read-out by a secondary capture bead array. We demonstrate in a proof-of-concept setting that target detection via two sequential affinity interactions reduced off-target contribution, while lowered background and noise levels, improved correlation to clinical values compared to single binder assays. We also compared sensitivity levels with single binder and classical sandwich assays, explored the possibility for DNA-based signal amplification, and demonstrate the applicability of the dual capture bead-based antibody microarray for biomarker analysis. Hence, the described concept enhances the possibilities for antibody array assays to be utilized for protein profiling in body fluids and beyond.
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