| 1. |
- Al-Rabadi, Laith Farah, et al.
(författare)
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Serine Protease HTRA1 as a Novel Target Antigen in Primary Membranous Nephropathy
- 2021
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Ingår i: Journal of the American Society of Nephrology. - : American Society of Nephrology (ASN). - 1046-6673 .- 1533-3450. ; 32:7, s. 1666-1681
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Tidskriftsartikel (refereegranskat)abstract
- Background Identification of target antigens PLA2R, THSD7A, NELL1, or Semaphorin-3B can explain the majority of cases of primary membranous nephropathy (MN). However, target antigens remain unidentified in 15%-20% of patients. Methods A multipronged approach, using traditional and modern technologies, converged on a novel target antigen, and capitalized on the temporal variation in autoantibody titer for biomarker discovery. Immunoblotting of human glomerular proteins followed by differential immunoprecipitation and mass spectrometric analysis was complemented by laser-capture microdissection followed by mass spectrometry, elution of immune complexes from renal biopsy specimen tissue, and autoimmune profiling on a protein fragment microarray. Results These approaches identified serine protease HTRA1 as a novel podocyte antigen in a subset of patients with primary MN. Sera from two patients reacted by immunoblotting with a 51-kD protein within glomerular extract and with recombinant human HTRA1, under reducing and nonreducing conditions. Longitudinal serum samples from these patients seemed to correlate with clinical disease activity. As in PLA2R- and THSD7A- associated MN, anti-HTRA1 antibodies were predominantly IgG4, suggesting a primary etiology. Analysis of sera collected during active disease versus remission on protein fragment microarrays detected significantly higher titers of anti-HTRA1 antibody in active disease. HTRA1 was specifically detected within immune deposits of HTRA1-associated MN in 14 patients identified among three cohorts. Screening of 118 "quadruple-negative" (PLA2R-, THSD7A-, NELL1-, EXT2-negative) patients in a large repository of MN biopsy specimens revealed a prevalence of 4.2%. Conclusions Conventional and more modern techniques converged to identify serine protease HTRA1 as a target antigen in MN.
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| 2. |
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| 3. |
- Bremer, Hanna, et al.
(författare)
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ILF2 and ILF3 are autoantigens in canine systemic autoimmune disease
- 2018
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Dogs can spontaneously develop complex systemic autoimmune disorders, with similarities to human autoimmune disease. Autoantibodies directed at self-antigens are a key feature of these autoimmune diseases. Here we report the identification of interleukin enhancer-binding factors 2 and 3 (ILF2 and ILF3) as autoantigens in canine immune-mediated rheumatic disease. The ILF2 autoantibodies were discovered in a small, selected canine cohort through the use of human protein arrays; a method not previously described in dogs. Subsequently, ILF3 autoantibodies were also identified in the same cohort. The results were validated with an independent method in a larger cohort of dogs. ILF2 and ILF3 autoantibodies were found exclusively, and at a high frequency, in dogs that showed a speckled pattern of antinuclear antibodies on immunofluorescence. ILF2 and ILF3 autoantibodies were also found at low frequency in human patients with SLE and Sjogren's syndrome. These autoantibodies have the potential to be used as diagnostic biomarkers for canine, and possibly also human, autoimmune disease.
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| 4. |
- Colwill, Karen, et al.
(författare)
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A roadmap to generate renewable protein binders to the human proteome
- 2011
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Ingår i: Nature Methods. - : Nature America Inc.. - 1548-7091 .- 1548-7105. ; 8:7, s. 551-8
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Tidskriftsartikel (refereegranskat)abstract
- Despite the wealth of commercially available antibodies to human proteins, research is often hindered by their inconsistent validation, their poor performance and the inadequate coverage of the proteome. These issues could be addressed by systematic, genome-wide efforts to generate and validate renewable protein binders. We report a multicenter study to assess the potential of hybridoma and phage-display technologies in a coordinated large-scale antibody generation and validation effort. We produced over 1,000 antibodies targeting 20 SH2 domain proteins and evaluated them for potency and specificity by enzyme-linked immunosorbent assay (ELISA), protein microarray and surface plasmon resonance (SPR). We also tested selected antibodies in immunoprecipitation, immunoblotting and immunofluorescence assays. Our results show that high-affinity, high-specificity renewable antibodies generated by different technologies can be produced quickly and efficiently. We believe that this work serves as a foundation and template for future larger-scale studies to create renewable protein binders.
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| 5. |
- Dou, Diana R., et al.
(författare)
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Xist ribonucleoproteins promote female sex-biased autoimmunity
- 2024
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Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 187:3, s. 16-733
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Tidskriftsartikel (refereegranskat)abstract
- Autoimmune diseases disproportionately affect females more than males. The XX sex chromosome complement is strongly associated with susceptibility to autoimmunity. Xist long non-coding RNA (lncRNA) is expressed only in females to randomly inactivate one of the two X chromosomes to achieve gene dosage compensation. Here, we show that the Xist ribonucleoprotein (RNP) complex comprising numerous autoantigenic components is an important driver of sex-biased autoimmunity. Inducible transgenic expression of a non-silencing form of Xist in male mice introduced Xist RNP complexes and sufficed to produce autoantibodies. Male SJL/J mice expressing transgenic Xist developed more severe multi-organ pathology in a pristane-induced lupus model than wild-type males. Xist expression in males reprogrammed T and B cell populations and chromatin states to more resemble wild-type females. Human patients with autoimmune diseases displayed significant autoantibodies to multiple components of XIST RNP. Thus, a sex-specific lncRNA scaffolds ubiquitous RNP components to drive sex-biased immunity.
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| 6. |
- Fuentes, Manuel, et al.
(författare)
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Exploring High-Throughput Immunoassays for Biomarker Validation in Rheumatic Diseases in the Context of the Human Proteome Project
- 2023
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Ingår i: Journal of Proteome Research. - : American Chemical Society. - 1535-3893 .- 1535-3907. ; 22:4, s. 1105-1115
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Tidskriftsartikel (refereegranskat)abstract
- Rheumatic diseases are high prevalence pathologies with different etiology and evolution and low sensitivity in clinical diagnosis. Therefore, it is necessary to develop an early diagnosis method which allows personalized treatment, depending on the specific pathology. The biology/disease initiative, at Human Proteome Project, is an integrative approach to identify relevant proteins in the human proteome associated with pathologies. A previously reported literature data mining analysis, which identified proteins related to osteoarthritis (OA), rheumatoid arthritis (RA), and psoriatic arthritis (PSA) was used to establish a systematic prioritization of potential biomarkers candidates for further evaluation by functional proteomics studies. The aim was to study the protein profile of serum samples from patients with rheumatic diseases such as OA, RA, and PSA. To achieve this goal, customized antibody microarrays (containing 151 antibodies targeting 121 specific proteins) were used to identify biomarkers related to early and specific diagnosis in a screening of 960 serum samples (nondepleted) (OA, n = 480; RA, n = 192; PSA, n = 288). This functional proteomics screening has allowed the determination of a panel (30 serum proteins) as potential biomarkers for these rheumatic diseases, displaying receiver operating characteristics curves with area under the curve values of 80-90%.
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| 7. |
- Gantelius, Jesper, et al.
(författare)
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A Lateral Flow Protein Microarray for Rapid and Sensitive Antibody Assays
- 2011
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 12:11, s. 7748-7759
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Tidskriftsartikel (refereegranskat)abstract
- Protein microarrays are useful tools for highly multiplexed determination of presence or levels of clinically relevant biomarkers in human tissues and biofluids. However, such tools have thus far been restricted to laboratory environments. Here, we present a novel 384-plexed easy to use lateral flow protein microarray device capable of sensitive (<30 ng/mL) determination of antigen-specific antibodies in ten minutes of total assay time. Results were developed with gold nanobeads and could be recorded by a cell-phone camera or table top scanner. Excellent accuracy with an area under curve (AUC of 98% was achieved in comparison with an established glass microarray assay for 26 antigen-specific antibodies. We propose that the presented framework could find use in convenient and cost-efficient quality control of antibody production, as well as in providing a platform for multiplexed affinity-based assays in low-resource or mobile settings.
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| 8. |
- Gantelius, Jesper, et al.
(författare)
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A ten-minute high density lateral flow protein microarray assay
- 2011
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Ingår i: 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011. - 9781618395955 ; , s. 1176-1178
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Konferensbidrag (refereegranskat)abstract
- Protein microarrays are useful tools for highly multiplexed determination of presence or levels of clinically relevant biomarkers in human tissues and biofluids. However, such tools have thus far been restricted to laboratory environments. Here, we present a novel 384-plexed easy to use lateral flow protein microarray device capable of sensitive (<50ng/ml) determination of antigen specific antibodies in less than ten minutes total assay time. Results were developed with gold nanobeads and could be recorded by a cell-phone camera or table top scanner. Excellent accuracy (AUC=99.4%) was achieved in comparison with an established glass microarray assay for 26 antigen-specific antibodies.
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| 9. |
- Hellström, Cecilia, et al.
(författare)
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High-density serum/plasma reverse phase protein arrays
- 2017
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Ingår i: Serum/Plasma Proteomics. - New York, NY : Humana Press. ; , s. 229-238
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Bokkapitel (refereegranskat)abstract
- In-depth exploration and characterization of human serum and plasma proteomes is an attractive strategy for the identification of potential prognostic or diagnostic biomarkers. The possibility of analyzing larger numbers of samples in a high-throughput fashion has markedly increased with affinity-based microarrays, thus providing higher statistical power to these biomarker studies. Here, we describe a protocol for high-density serum and plasma reverse phase protein arrays (RPPAs). We demonstrate how a biobank of 12,392 samples was immobilized and analyzed on a single microarray slide, allowing high-quality profiling of abundant target proteins across all samples in one assay.
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| 10. |
- Hober, Sophia, Professor, 1965-, et al.
(författare)
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Systematic evaluation of SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay
- 2021
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Ingår i: Clinical & Translational Immunology. - : Wiley. - 2050-0068. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The COVID-19 pandemic poses an immense need for accurate, sensitive and high-throughput clinical tests, and serological assays are needed for both overarching epidemiological studies and evaluating vaccines. Here, we present the development and validation of a high-throughput multiplex bead-based serological assay. Methods. More than 100 representations of SARS-CoV-2 proteins were included for initial evaluation, including antigens produced in bacterial and mammalian hosts as well as synthetic peptides. The five best-performing antigens, three representing the spike glycoprotein and two representing the nucleocapsid protein, were further evaluated for detection of IgG antibodies in samples from 331 COVID-19 patients and convalescents, and in 2090 negative controls sampled before 2020. Results. Three antigens were finally selected, represented by a soluble trimeric form and the S1-domain of the spike glycoprotein as well as by the C-terminal domain of the nucleocapsid. The sensitivity for these three antigens individually was found to be 99.7%, 99.1% and 99.7%, and the specificity was found to be 98.1%, 98.7% and 95.7%. The best assay performance was although achieved when utilising two antigens in combination, enabling a sensitivity of up to 99.7% combined with a specificity of 100%. Requiring any two of the three antigens resulted in a sensitivity of 99.7% and a specificity of 99.4%. Conclusion. These observations demonstrate that a serological test based on a combination of several SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay.
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| 11. |
- Hong, Mun-Gwan, et al.
(författare)
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Profiles of histidine-rich glycoprotein associate with age and risk of all-cause mortality
- 2020
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Ingår i: Life Science Alliance. - : Life Science Alliance, LLC. - 2575-1077. ; 3:10, s. e202000817-
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Tidskriftsartikel (refereegranskat)abstract
- Despite recognizing aging as a common risk factor of many human diseases, little is known about its molecular traits. To identify age-associated proteins circulating in human blood, we screened 156 individuals aged 50–92 using exploratory and multiplexed affinity proteomics assays. Profiling eight additional study sets (N = 3,987), performing antibody validation, and conducting a meta-analysis revealed a consistent age association (P = 6.61 × 10−6) for circulating histidine-rich glycoprotein (HRG). Sequence variants of HRG influenced how the protein was recognized in the immunoassays. Indeed, only the HRG profiles affected by rs9898 were associated with age and predicted the risk of mortality (HR = 1.25 per SD; 95% CI = 1.12–1.39; P = 6.45 × 10−5) during a follow-up period of 8.5 yr after blood sampling (IQR = 7.7–9.3 yr). Our affinity proteomics analysis found associations between the particular molecular traits of circulating HRG with age and all-cause mortality. The distinct profiles of this multipurpose protein could serve as an accessible and informative indicator of the physiological processes related to biological aging.
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| 12. |
- Janzi, Magdalena, et al.
(författare)
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Screening for C3 deficiency in newborns using microarrays.
- 2009
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:4, s. e5321-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Dried blood spot samples (DBSS) from newborns are widely used in neonatal screening for selected metabolic diseases and diagnostic possibilities for additional disorders are continuously being evaluated. Primary immunodeficiency disorders comprise a group of more than one hundred diseases, several of which are fatal early in life. Yet, a majority of the patients are not diagnosed due to lack of high-throughput screening methods.METHODOLOGY/PRINCIPAL FINDINGS: We have previously developed a system using reverse phase protein microarrays for analysis of IgA levels in serum samples. In this study, we extended the applicability of the method to include determination of complement component C3 levels in eluates from DBSS collected at birth. Normal levels of C3 were readily detected in 269 DBSS from healthy newborns, while no C3 was detected in sera and DBSS from C3 deficient patients.CONCLUSIONS/SIGNIFICANCE: The findings suggest that patients with deficiencies of specific serum proteins can be identified by analysis of DBSS using reverse phase protein microarrays.
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| 13. |
- Janzi, Magdalena, et al.
(författare)
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Selective IgA deficiency in early life : Association to infections and allergic diseases during childhood
- 2009
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Ingår i: Clinical Immunology. - : Elsevier BV. - 1521-6616 .- 1521-7035. ; 133:1, s. 78-85
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Tidskriftsartikel (refereegranskat)abstract
- Selective IgA deficiency in early life is quite common in Caucasian populations, but it is unclear whether it increases the risk of infections and allergic diseases during childhood. Serum IgA levels were measured in 2423 children at 4 years of age in a Swedish population based birth cohort (BAMSE). Parental questionnaires were repeatedly sent out during the child's first 8 years of life, collecting information about infections and allergic diseases. 14 children (1:173) were found to be IgA deficient at 4 years of age. These children had an increased risk of pseudocroup at year 1 (p<0.01) and food hypersensitivity at year 4 (p<0.05) as compared to IgA sufficient children. No increased risk was observed in the partial IgA deficiency group. The findings suggest that selective IgA deficiency may increase the risk of parentally reported pseudocroup and food hypersensitivity during early childhood.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Lourido, L., et al.
(författare)
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PRESENCE OF FOUR SERUM AUTOANTIBODIES ASSOCIATES WITH THE ACPA STATUS IN EARLY RHEUMATOID ARTHRITIS
- 2021
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ Publishing Group Ltd. - 0003-4967 .- 1468-2060. ; 80, s. 425-426
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The presence of anti-citrullinated protein antibodies (ACPAs) is a hallmark of rheumatoid arthritis (RA) that precede the development of the disease by years and is used for its clinical diagnosis. However, there are RA subjects that test negative for ACPA and thus the early diagnosis on these patients may be delayed. Furthermore, the presence or absence of ACPA in RA supports the hypothesis that on these two subsets of patients underlie different pathogenesis and clinical outcomes.Objectives:In this work, we searched for serum autoantibodies useful to assist the early diagnosis of ACPA-seronegative RA and its management.Methods:We profiled the serum autoantibody repertoire of 80 ACPA-seronegative and 80 ACPA-seropositive RA subjects from the Swedish population-based Epidemiological Investigation of RA (EIRA) cohort. A suspension bead array platform built on protein fragments within Human Protein Atlas and selected from an initial untargeted screening using arrays containing 2660 total antigens was employed to identify IgG and IgA serum autoantibodies. A validation phase on antigen suspension bead arrays was carried out on another set of samples from EIRA containing 386 ACPA-seropositive, 358 ACPA-seronegative and 372 randomly selected control subjects of the same age and sex. A sample-specific threshold based on 20 times the median absolute deviation plus the median of all signals was selected to determine the reactivity of samples. The Wilcoxon rank sum test and Fisher’s test were applied for the comparison of autoantibody levels and reactivity frequencies between the groups.Results:Our data revealed four antigens associated with the ACPA status (Table 1). Testis-specific Y-encoded-like protein 4 (TSPYL4) showed significantly higher IgG reactivity frequency in ACPA-seronegative subjects compared to ACPA-seropositive (8% vs. 3%; P<0.05). Significant differences at IgG autoantibody levels (P<0.05) were also observed between ACPA-seronegative subjects and controls for this specific antigen. Significantly higher IgG autoantibody levels (P<0.05) towards another antigen, dual specificity mitogen-activated protein kinase kinase 6 (MAP2K6), were also observed in ACPA-seronegative subjects compared to ACPA-seropositive and controls. In contrast, we found significantly higher IgG autoantibody levels (P<0.05) in ACPA-seropositive individuals compared to ACPA-seronegative and controls towards two antigens, anosmin-1 (ANOS-1) and muscle related coiled-coil protein (MURC). ANOS-1 shows also significantly higher IgG reactivity frequency in ACPA-seropositive individuals compared to ACPA-seronegative and controls (22%, 9% and 6% respectively; P<0.05). Interestingly, three out of the four antigens discovered to be associated with the ACPA status in early RA are highly expressed in lungs and heart, two of the main extraarticular sites affected in RA. No significant differences were observed at IgA levels for any of the antigens analyzed.Table 1.Scheme of the different phases of the study, the features within each phase and the results. The reactivity to four antigens allows to distinguish ACPA-seronegative (ACPA-), ACPA seropositive (ACPA+) and controls.PhasesUntargeteddiscoveryTargeteddiscoveryTargetedvalidationNumber of samples80 ACPA-80 ACPA-358 ACPA-372 Controls80 ACPA+80 ACPA+386 ACPA+Antigen arrayplatformPlanararraysSuspensionbead array 1Suspensionbead array 2Number of antigens26606227Number of candidatebiomarkers6227 4 (TSPYL4,MAP2K6,ANOS1,MURC)Conclusion:Upon further validation in other early RA sample cohorts, our data suggest the measurement of these four autoantibodies may be useful for the early diagnosis of ACPA-seronegative RA and give insight into the pathogenesis of the different RA subsets.Characters from table content including title and footnotes:Disclosure of Interests:None declared
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| 18. |
- Mathsson, Linda, et al.
(författare)
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Antibodies against citrullinated vimentin in rheumatoid arthritis : Higher sensitivity and extended prognostic value concerning future radiographic progression as compared with antibodies against cyclic citrullinated peptides
- 2008
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 58:1, s. 36-45
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The Sa autoantigen can be found in inflamed synovium of patients with rheumatoid arthritis (RA), and at least part of the humoral RA-specific anti-Sa response is directed against citrullinated vimentin. This study was undertaken to evaluate the sensitivity, specificity, and prognostic value of determination of levels of antibodies against modified citrullinated vimentin (anti-MCV) as compared with antibodies against cyclic citrullinated peptides (anti-CCP) in an inception cohort of patients with early RA. METHODS: Clinical data, radiographs, and measurements of levels of anti-MCV and anti-CCP antibodies were obtained in 273 patients with early RA at baseline, after 3 months, and after 1, 2, 3, and 5 years. Autoantibodies were also analyzed in 100 healthy controls. RESULTS: Of the 273 patients, 193 (70.7%) were anti-MCV positive and 158 (57.9%) were anti-CCP positive at the time of diagnosis, with nearly equal specificities (95% and 96%, respectively). Forty (14.7%) were anti-MCV positive only, and 5 (1.8%) were anti-CCP positive only. Anti-MCV-positive and anti-MCV-negative patients had similar disease activity at baseline, but presence of anti-MCV was predictive of subsequent high disease activity and continued radiographic progression. Changes in anti-MCV level showed stronger correlation with changes in clinical parameters than did changes in anti-CCP level. The subgroup of patients who were anti-MCV positive and anti-CCP negative showed a higher rate of radiographic destruction than did patients who were negative for both anti-MCV and anti-CCP. CONCLUSION: These findings show that when patients with early RA are compared with healthy controls, analysis of anti-MCV yields greater sensitivity and unchanged specificity as compared with analysis of anti-CCP. Anti-MCV also appears to perform better than anti-CCP in identifying poor radiographic prognosis in patients with early RA.
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| 19. |
- Mikus, Maria, et al.
(författare)
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Allergome-wide peptide microarrays enable epitope deconvolution in allergen-specific immunotherapy
- 2020
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Ingår i: Journal of Allergy and Clinical Immunology. - : Mosby Inc.. - 0091-6749 .- 1097-6825.
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Tidskriftsartikel (refereegranskat)abstract
- Background: The interaction of allergens and allergen-specific IgE initiates the allergic cascade after crosslinking of receptors on effector cells. Antibodies of other isotypes may modulate such a reaction. Receptor crosslinking requires binding of antibodies to multiple epitopes on the allergen. Limited information is available on the complexity of the epitope structure of most allergens. Objectives: We sought to allow description of the complexity of IgE, IgG4, and IgG epitope recognition at a global, allergome-wide level during allergen-specific immunotherapy (AIT). Methods: We generated an allergome-wide microarray comprising 731 allergens in the form of more than 172,000 overlapping 16-mer peptides. Allergen recognition by IgE, IgG4, and IgG was examined in serum samples collected from subjects undergoing AIT against pollen allergy. Results: Extensive induction of linear peptide-specific Phl p 1– and Bet v 1–specific humoral immunity was demonstrated in subjects undergoing a 3-year-long AIT against grass and birch pollen allergy, respectively. Epitope profiles differed between subjects but were largely established already after 1 year of AIT, suggesting that dominant allergen-specific antibody clones remained as important contributors to humoral immunity following their initial establishment during the early phase of AIT. Complex, subject-specific patterns of allergen isoform and group cross-reactivities in the repertoires were observed, patterns that may indicate different levels of protection against different allergen sources. Conclusions: The study highlights the complexity and subject-specific nature of allergen epitopes recognized following AIT. We envisage that epitope deconvolution will be an important aspect of future efforts to describe and analyze the outcomes of AIT in a personalized manner.
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| 20. |
- Olofsson, Jennie, et al.
(författare)
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Array-Based Multiplex and High-Throughput Serology Assays
- 2023
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Ingår i: Methods in Molecular Biology. - New York, NY : Springer Nature. - 1064-3745 .- 1940-6029. ; 2628, s. 535-553
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Tidskriftsartikel (refereegranskat)abstract
- The detection of antibody responses using serological tests provides means to diagnose infections, follow disease transmission, and monitor vaccination responses. The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, highlighted the need for rapid development of robust and reliable serological tests to follow disease spreading. Moreover, the rise of SARS-CoV-2 variants emphasized the need to monitor their transmission and prevalence in the population. For this reason, multiplex and flexible serological assays are needed to allow for rapid inclusion of antigens representing new variants as soon as they appear. In this chapter, we describe the generation and application of a multiplex serological test, based on bead array technology, to detect anti-SARS-CoV-2 antibodies in a high-throughput manner, using only a few microliters of sample. This method is currently expanding to include a multi-disease antigen panel that will allow parallel detection of antibodies towards several infectious agents.
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| 21. |
- Pin, Elisa, et al.
(författare)
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Array-based profiling of proteins and autoantibody repertoires in CSF
- 2019
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Ingår i: Cerebrospinal Fluid (CSF) Proteomics. - New York, NY : Humana Press Inc.. ; , s. 303-318
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Bokkapitel (refereegranskat)abstract
- Protein profiling enabled through affinity proteomics represents a powerful strategy for analysis of complex samples such as human body fluids. Cerebrospinal fluid (CSF) is the proximal fluid of the central nervous system and is commonly analyzed in the context of neurological diseases. Through the presence of brain-derived proteins, this fluid can offer insight into the physiological state of the brain. Here, we describe multiplex and flexible protein and autoantibody profiling approaches using suspension bead arrays. Through minimal sample processing, these methods enable high-throughput analysis of hundreds of samples and proteins in one single assay and thereby provide powerful approaches for discovery of disease-associated proteins and autoantigens.
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| 22. |
- Qundos, Ulrika, et al.
(författare)
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Affinity proteomics discovers decreased levels of AMFR in plasma from Osteoporosis patients
- 2016
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Ingår i: PROTEOMICS - Clinical Applications. - : Wiley-Blackwell. - 1862-8346 .- 1862-8354. ; 10:6, s. 681-690
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Affinity proteomic approaches by antibody bead arrays enable multiplexed analysis of proteins in body fluids. In the presented study, we investigated blood plasma within osteoporosis to discovery differential protein profiles and to propose novel biomarkers candidates for subsequent studies. Experimental design: Starting with 4608 antibodies and plasma samples from 22 women for an untargeted screening, a set of 72 proteins were suggested for further analysis. Complementing these with targets from literature and other studies, a targeted bead array of 180 antibodies was built to profile for 92 proteins in plasma samples of 180 women from two independent population-based studies. Results: Differential profiles between osteoporosis patients and matched controls were discovered for 12 proteins in at least one of the two study sets. Among these targets, the levels of autocrine motility factor receptor (AMFR) were concordantly lower in plasma of female osteoporosis patients. Subsequently, verification of anti-AMFR antibody selectivity was conducted using high-density peptide and protein arrays, and Western blotting. Conclusions and clinical relevance: Further validation in additional study sets will be needed to determine the clinical value of the observed decrease in AMFR plasma levels in osteoporosis patients, but AMFR may aid our understanding of disease mechanisms and could support existing tools for diagnosis and monitoring of patient mobility within osteoporosis.
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| 23. |
- Rimini, Rebecca, et al.
(författare)
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Validation of serum protein profiles by a dual antibody array approach
- 2009
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 73:2, s. 252-266
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, affinity-based technologies have become important tools for serum profiling to uncover protein expression patterns linked to disease state or therapeutic effects. In this study, we describe a path towards the production of an antibody microarray to allow protein profiling of biotinylated human serum samples with reproducible sensitivity in the picomolar range. With the availability of growing numbers of affinity reagents, protein profiles are to be validated in efficient manners and we describe a cross-platform strategy based on data concordance with a suspension bead array to interrogate the identical set of antibodies with the same cohort of serum samples. Comparative analysis enabled to screen for high-performing antibodies, which were displaying consistent results across the two platforms and targeting known serum components. Moreover, data processing methods such as sample referencing and normalization were evaluated for their effects on inter-platform agreement. Our work suggests that mutual validation of protein expression profiles using alternative microarray platforms holds great potential in becoming an important and valuable component in affinity-based high-throughput proteomic screenings as it allows to narrow down the number of discovered targets prior to orthogonal, uniplexed validation approaches.
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| 24. |
- Rudberg, Ann-Sofie, et al.
(författare)
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SARS-CoV-2 exposure, symptoms and seroprevalence in healthcare workers in Sweden.
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- SARS-CoV-2 may pose an occupational health risk to healthcare workers. Here, we report the seroprevalence of SARS-CoV-2 antibodies, self-reported symptoms and occupational exposure to SARS-CoV-2 among healthcare workers at a large acute care hospital in Sweden. The seroprevalence of IgG antibodies against SARS-CoV-2 was 19.1% among the 2149 healthcare workers recruited between April 14th and May 8th 2020, which was higher than the reported regional seroprevalence during the same time period. Symptoms associated with seroprevalence were anosmia (odds ratio (OR) 28.4, 95% CI 20.6-39.5) and ageusia (OR 19.2, 95% CI 14.3-26.1). Seroprevalence was also associated with patient contact (OR 2.9, 95% CI 1.9-4.5) and covid-19 patient contact (OR 3.3, 95% CI 2.2-5.3). These findings imply an occupational risk for SARS-CoV-2 infection among healthcare workers. Continued measures are warranted to assure healthcare workers safety and reduce transmission from healthcare workers to patients and to the community.
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| 25. |
- Sahlin, Margareta, et al.
(författare)
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Peroxyl adduct radicals formed in the iron/oxygen reconstitution reaction of mutant ribonucleotide reductase R2 proteins from Escherichia coli.
- 2002
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Ingår i: J Biol Inorg Chem. - 0949-8257. ; 7:1-2, s. 74-82
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Catalytically important free radicals in enzymes are generally formed at highly specific sites, but the specificity is often lost in point mutants where crucial residues have been changed. Among the transient free radicals earlier found in the Y122F mutant of protein R2 in Escherichia coli ribonucleotide reductase after reconstitution with Fe2+ and O2, two were identified as tryptophan radicals. A third radical has an axially symmetric EPR spectrum, and is shown here using 17O exchange and simulations of EPR spectra to be a peroxyl adduct radical. Reconstitution of other mutants of protein R2 (i.e. Y122F/W48Y and Y122F/W107Y) implicates W48 as the origin of the peroxyl adduct. The results indicate that peroxyl radicals form on primary transient radicals on surface residues such as W48, which is accessible to oxygen. However, the specificity of the reaction is not absolute since the single mutant W48Y also gives rise to a peroxyl adduct radical. We used density functional calculations to investigate residue-specific effects on hyperfine coupling constants using models of tryptophan, tyrosine, glycine and cysteine. The results indicate that any peroxyl adduct radical attached to the first three amino acid alpha-carbons gives similar 17O hyperfine coupling constants. Structural arguments and experimental results favor W48 as the major site of peroxyl adducts in the mutant Y122F. Available molecular oxygen can be considered as a spin trap for surface-located protein free radicals.
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| 26. |
- Sierra-Sanchez, Alvaro, et al.
(författare)
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Screening and Validation of Novel Biomarkers in Osteoarticular Pathologies by Comprehensive Combination of Protein Array Technologies
- 2017
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 16:5, s. 1890-1899
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Tidskriftsartikel (refereegranskat)abstract
- Osteoarthritis (OA) is one of the most prevalent articular diseases. The identification of proteins closely associated with the diagnosis, progression, prognosis, and treatment response is dramatically required for this pathology. In this work, differential serum protein profiles have been identified in OA and rheumatoid arthritis (RA) by antibody arrays containing 151 antibodies against 121 antigens in a cohort of 36 samples. Then the identified differential serum protein profiles have been validated in a larger cohort of 282 samples. The overall immunoreactivity is higher in the pathological situations in comparison with the controls. Several proteins have been identified as biomarker candidates for OA and RA. Most of these biomarker candidates are proteins related to inflammatory response, lipid metabolism, or bone and extracellular matrix formation, degradation, or remodeling.
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| 27. |
- Sjöberg, Ronald, et al.
(författare)
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Biosensor based protein profiling on reverse phase serum microarray
- 2012
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Ingår i: Journal of Proteomics and Bioinformatics. - : OMICS Publishing Group. - 0974-276X. ; 5:8, s. 185-189
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Tidskriftsartikel (refereegranskat)abstract
- The reverse phase serum microarray format enables multi-parallel and simultaneous analysis of literally thousands of samples, a feature which is of uttermost importance for protein profiling of clinical samples. We have here screened 2400 serum samples for their potential IgA deficiency by using a fluorescence based reverse phase serum microarray platform and a biosensor based label-free microarray platform for verification and also compared our microarray-results to clinical routine ELISA. We have been able to identify possible IgA-deficiencies and to show the suitability of our microarray-platforms for large-scale screening of clinical serum samples. The two microarray methods show reproducibility and correlation towards each other and low variation between replicates within each platform. Both of the microarray platforms show less agreement towards ELISA. The fluorescence based microarray method has been shown to be applicable for large-scale screening of clinically important serum samples for detection of possibly IgA-deficient patients. Furthermore, it was found that the microarray based biosensor method could be used for determining the relative differences in concentration of IgA between the samples.
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| 28. |
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| 29. |
- Sjöberg, Ronald, et al.
(författare)
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Exploration of high-density protein microarrays for antibody validation and autoimmunity profiling
- 2016
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Ingår i: New Biotechnology. - : Elsevier. - 1871-6784 .- 1876-4347. ; 33:5, s. 582-592
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Tidskriftsartikel (refereegranskat)abstract
- High-density protein microarrays of recombinant human protein fragments, representing 12,412 unique Ensembl Gene IDs, have here been produced and explored. These protein microarrays were used to analyse antibody off-target interactions, as well as for profiling the human autoantibody repertoire in plasma against the antigens represented by the protein fragments. Affinity-purified polyclonal antibodies produced within the Human Protein Atlas (HPA) were analysed on microarrays of three different sizes, ranging from 384 antigens to 21,120 antigens, for evaluation of the antibody validation criteria in the HPA. Plasma samples from secondary progressive multiple sclerosis patients were also screened in order to explore the feasibility of these arrays for broad-scale profiling of autoantibody reactivity. Furthermore, analysis on these near proteome-wide microarrays was complemented with analysis on HuProt (TM) Human Proteome protein microarrays. The HPA recombinant protein microarray with 21,120 antigens and the HuProt (TM) Human Proteome protein microarray are currently the largest protein microarray platforms available to date. The results on these arrays show that the Human Protein Atlas antibodies have few off-target interactions if the antibody validation criteria are kept stringent and demonstrate that the HPA-produced high-density recombinant protein fragment microarrays allow for a high-throughput analysis of plasma for identification of possible autoantibody targets in the context of various autoimmune conditions.
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| 30. |
- Sjöberg, Ronald, et al.
(författare)
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High-density antigen microarrays for the assessment of antibody selectivity and off-target binding
- 2018
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Ingår i: Epitope Mapping Protocols. - New York, NY : Humana Press Inc.. - 9781493978397 ; , s. 231-238
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Bokkapitel (refereegranskat)abstract
- With the increasing availability of collections of antibodies, their evaluation in terms of binding selectivity becomes an important but challenging task. Planar antigen microarrays are very suitable tools to address this task and provide a powerful proteomics platform for the characterization of the binding selectivity of antibodies toward thousands of antigens in parallel. In this chapter, we describe our in-house developed procedures for the generation of high-density planar antigen microarrays with over 21,000 features. We also provide the details of the assay protocol, which we routinely use for the assessment of binding selectivity of the polyclonal antibodies generated within the Human Protein Atlas.
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| 31. |
- Sjöberg, Ronald, 1974-
(författare)
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On Generation and Applications of High-Density Protein Microarrays
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Affinity proteomics has experienced rapid development over the last two decades and one of the most promising platforms to emerge are the protein microarrays. The combination of affinity reagents and miniaturisation enables assays for simultaneous high throughput and sensitive protein analysis. Due to the combination of these desrable properties, a multitude of protein array platforms for rapid and efficient study of proteomes and protein interactions are in use today. Although the protein microarray field has more than two decades of history to look back on the development of new protein microarray platforms continues to this day and beyond.In the paper I in this thesis, a microarray of eluates from dried blood spot samples collected from neonates were designed and utilised for detection of complement factor 3 (C3) deficiency. The data acquired from the microarrays platform were compared to C3 levels obtained through enzyme-linked immunosorbant assay (ELISA), and the microarray assay were found to separate the C3 deficient samples from the controls. The conclusion of this investigation was that the microarray platform would be suitable for high-throughput screening of C3 deficiency in neonates. Paper II outlines the work in developing a multiplex platform for validation of affinity reagents. A set of 398 affinity binders, originating from five research groups, were profiled against 432 antigens and representing both polyclonal rabbit antibodies, monoclonal mouse antibodies, and recombinant single-chain variable fragments. Approximately 50% of the binders were found to preferably recognise their intended target while 10% of the binders did not generate any, or low, signals with their respective targets. For paper III, a reverse phase array (RPPA) platform using fluorescence-based detection of IgA deficiency in over 2.000 samples where validated on a label-free detection system and ELISA. The data from the label-free platform and the RPPA were found agree well with each other while data from ELISA did with neither of them. It was found that the label-free platform proved to be well-suited for detection of IgA in serum. Paper IV describes one of the world’s largest protein microarrays containing 21.120 recombinant protein fragments. We describe some of the possible applications of these large-scale arrays, such as binding profiles for the validation of antibodies with 11.520 and 21.120 recombinant proteins, as well as screening for autoimmunity in human serum samples.
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| 32. |
- Sjöberg, Ronald, et al.
(författare)
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Validation of affinity reagents using antigen microarrays
- 2011
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Ingår i: New Biotechnology. - : Elsevier BV. - 1871-6784 .- 1876-4347. ; 29:5, s. 555-563
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- There is a need for standardised validation of affinity reagents to determine their binding selectivity and specificity. This is of particular importance for systematic efforts that aim to cover the human proteome with different types of binding reagents. One such international program is the SH2-consortium, which was formed to generate a complete set of renewable affinity reagents to the SH2-domain containing human proteins. Here, we describe a microarray strategy to validate various affinity reagents, such as recombinant single-chain antibodies, mouse monoclonal antibodies and antigen-purified polyclonal antibodies using a highly multiplexed approach. An SH2-specific antigen microarray was designed and generated, containing more than 6000 spots displayed by 14 identical subarrays each with 406 antigens, where 105 of them represented SH2-domain containing proteins. Approximately 400 different affinity reagents of various types were analysed on these antigen microarrays carrying antigens of different types. The microarrays revealed not only very detailed specificity profiles for all the binders, but also showed that overlapping target sequences of spotted antigens were detected by off-target interactions. The presented study illustrates the feasibility of using antigen microarrays for integrative, high-throughput validation of various types of binders and antigens.
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| 33. |
- Ssengendo, Ronald, et al.
(författare)
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Computation of the Gravimetric Quasigeoid Model over Uganda Using the KTH Method
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The gravimetric quasigeoid can be determined either directly by Stokes formula or indirectly by computing the geoid first and then determining the quasigeoid-to-geoid separation which is then used to determine the quasigeoid. This paper presents the computational results of the gravimetric quasigeoid model over Uganda (UGQ2014) based on the later technique. UGQ2014 was derived from the Uganda Gravimetric Geoid Model (UGG2014) which was computed by the technique of Least Squares Modification of Stokes formula with additive corrections commonly called the KTH Method. UGG2014 was derived from sparse terrestrial gravity data from the International gravimetric Bureau, the 3 arc second SRTM ver4.1 Digital Elevation Model and the GOCE-only geopotential model GO_CONS_GCF_2_TIM_R5. The quasigeoid-to geoid separation was then computed from the Earth Gravitational Model 2008 (EGM08) complete to degree 2160 of spherical harmonics together with the global topographic model DTM2006.0 also complete to degree 2160.Another aim of this paper is to compare the approximate and strict formulas of computing the quasigeoid-to-geoid separation and evaluate their effects on the final quasigeoid model. Using 10 GNSS/levelling data points distributed over Uganda, the RMS fit of the quasigeoid model based on the approximate formula are 27 cm and 10 cm before and after a 4-parameter fit, respectively. Similarly, the RMS fit of the model based on the strict formula are 15 cm and 6 cm, respectively. The results show the improvement to the final quasigeoid model brought about by using the strict formula to model more effectively the terrain in the vicinity of the computation point. With an accuracy of 6 cm, UGQ2014 represents significant progress towards the computation of a final gravimetric geoid over Uganda which can be used with GNSS/levelling. However, with more data especially terrestrial gravity data and GNSS/levelling we anticipate that the accuracy of gravimetric quasigeoid modelling will improve in future.
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| 34. |
- Ssengendo, Ronald, et al.
(författare)
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Evaluation of EGM08 in Uganda : Preliminary Results
- 2011
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Ingår i: The first Conference on Advances in Geomatics Research. ; , s. 195-201
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Konferensbidrag (refereegranskat)abstract
- his paper presents an overview of the preliminary evaluation results of the new Earth Gravitational Model (EGM08) in Uganda. The evaluation was based on a network of 12 GNSS/levelling points in Kampala and was performed in point wise (absolute) and relative (varying baselines) sense. For completeness the evaluation tests were also performed for EGM96. Our preliminary results were inconclusive as in the absolute tests, EGM96 was unexpectedly significantly better than EGM08. However, in the relative tests, EGM08 was consistently better than EGM96 for all baseline lengths considered. Subsequently further tests with much higher density and distribution than our test network should be carried out to conclusively determine the best global model for geodetic applications in Uganda.
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| 35. |
- Ssengendo, Ronald, et al.
(författare)
-
The Uganda Gravimetric Geoid Model computed by the KTH Method
- 2015
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Ingår i: Journal of Geodetic Science. - : De Gruyter Open. - 2081-9919 .- 2081-9943. ; 5:2, s. 35-46
-
Tidskriftsartikel (refereegranskat)abstract
- For many developing countries such as Uganda, precise gravimetric geoid determination is hindered by the low quantity and quality of the terrestrial gravity data. With only one gravity data point per 65 km2, gravimetric geoid determination in Uganda appears an impossible task. However, recent advances in geoid modelling techniques coupled with the gravity-field anomalies from the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) satellite mission have opened new avenues for geoid determination especially for areas with sparse terrestrial gravity. The present study therefore investigates the computation of a gravimetric geoid model over Uganda (UGG2014) using the Least Squares Modification of Stokes formula with additive corrections. UGG2014 was derived from sparse terrestrial gravity data from the International Gravimetric Bureau, the 3 arc second SRTM ver4.1 Digital Elevation Model from CGIAR-CSI and the GOCE-only global geopotential model GO_CONS_GCF_2_TIM_R5. To compensate for the missing gravity data in the target area, we used the surface gravity anomalies extracted from the World Gravity Map 2012. Using 10 Global Navigation Satellite System (GNSS)/levelling data points distributed over Uganda, the RMS fit of the gravimetric geoid model before and after a 4-parameter fit is 11 cm and 7 cm respectively. These results show that UGG2014 agrees considerably better with GNSS/levelling than any other recent regional/global gravimetric geoid model. The results also emphasize the significant contribution of the GOCE satellite mission to the gravity field recovery, especially for areas with very limited terrestrial gravity data. With an RMS of 7 cm, UGG2014 is a significant step forward in the modelling of a “1-cm geoid” over Uganda despite the poor quality and quantity of the terrestrial gravity data used for its computation.
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| 36. |
- Thörnqvist, Linnea, et al.
(författare)
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Linear Epitope Binding Patterns of Grass Pollen-Specific Antibodies in Allergy and in Response to Allergen-Specific Immunotherapy
- 2022
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Ingår i: Frontiers in Allergy. - : Frontiers Media SA. - 2673-6101. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- Allergic diseases affect many individuals world-wide and are dependent on the interaction between allergens and antibodies of the IgE isotype. Allergen-specific immunotherapy (AIT) can alter the development of the disease, e.g., through induction of allergen-specific IgG that block allergen-IgE interactions. The knowledge of epitopes recognized by allergy-causing and protective antibodies are limited. Therefore, we developed an allergome-wide peptide microarray, aiming to track linear epitope binding patterns in allergic diseases and during AIT. Here, we focused on immune responses to grass pollen allergens and found that such epitopes were commonly recognized before initiation of AIT and that AIT commonly resulted in increased antibody production against additional epitopes already after 1 year of treatment. The linear epitope binding patterns were highly individual, both for subjects subjected to and for individuals not subjected to AIT. Still, antibodies against some linear epitopes were commonly developed during AIT. For example, the two rigid domains found in grass pollen group 5 allergens have previously been associated to a diversity of discontinuous epitopes. Here, we present evidence that also the flexible linker, connecting these domains, contains regions of linear epitopes against which antibodies are developed during AIT. We also describe some commonly recognized linear epitopes on Phl p 2 and suggest how antibodies against these epitopes may contribute to or prevent allergy in relation to a well-defined stereotyped/public IgE response against the same allergen. Finally, we identify epitopes that induce cross-reactive antibodies, but also antibodies that exclusively bind one of two highly similar variants of a linear epitope. Our findings highlight the complexity of antibody recognition of linear epitopes, with respect to both the studied individuals and the examined allergens. We expect that many of the findings in this study can be generalized also to discontinuous epitopes and that allergen peptide microarrays provide an important tool for enhancing the understanding of allergen-specific antibodies in allergic disease and during AIT.
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| 37. |
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| 38. |
- Zhou, Xiamo, 1990-, et al.
(författare)
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Thiol–ene–epoxy thermoset for low-temperature bonding to biofunctionalized microarray surfaces
- 2017
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry. - 1473-0197 .- 1473-0189. ; 17:21, s. 3672-3681
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Tidskriftsartikel (refereegranskat)abstract
- One way to improve the sensitivity and throughput of miniaturized biomolecular assays is to integrate microfluidics to enhance the transport efficiency of biomolecules to the reaction sites. Such microfluidic integration requires bonding of a prefabricated microfluidic gasket to an assay surface without destroying its biological activity. In this paper we address the largely unmet challenge to accomplish a proper seal between a microfluidic gasket and a protein surface, with maintained biological activity and without contaminating the surface or blocking the microfluidic channels. We introduce a novel dual cure polymer resin for the formation of microfluidic gaskets that can be room-temperature bonded to a range of substrates using only UVA light. This polymer is the first polymer that features over a month of shelf life between the structure formation and the bonding, moreover the fully cured polymer gaskets feature the following set of properties suitable for microfluidics: high stiffness, which prevents microfluidic channel collapse during handling; very limited absorption of biomolecules; and no significant leaching of uncured monomers. We describe the novel polymer resin and its characteristics, study through FT-IR, and demonstrate its use as microfluidic well-arrays bonded onto protein array slides at room temperature followed by multiplexed immunoassays. The results confirm maintained biological activity and show high repeatability between protein arrays. This new approach for integrating microfluidic gaskets to biofunctionalised surfaces has the potential to improve sample throughput and decrease manufacturing costs for miniaturized biomolecular systems.
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