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Discover how PEPperPRINT Peptide Microarray products have been used in different fields of research.

Autoimmune Atrial Fibrillation

Maguy, Ange; Mahendran, Yuvaraj; Tardif, Jean-Claude; Busseuil, David; Li, Jin
Circulation.
Aug 2023
BACKGROUND: Atrial fibrillation (AF) is by far the most common cardiac arrhythmia. In about 3% of individuals, AF develops as a primary disorder without any identifiable trigger (idiopathic or historically termed lone AF). In line with the emerging field of autoantibody-related cardiac arrhythmias, the objective of this study was to explore whether autoantibodies targeting cardiac ion channels can underlie unexplained AF. METHODS: Peptide microarray was used to screen patient samples for autoantibodies. We compared patients with unexplained AF (n=37 pre-existent AF; n=14 incident AF on follow-up) to age- and sex-matched controls (n=37). Electrophysiological properties of the identified autoantibody were then tested in vitro with the patch clamp technique and in vivo with an experimental mouse model of immunization. RESULTS: A common autoantibody response against K ir 3.4 protein was detected in patients with AF and even before the development of clinically apparent AF. K ir 3.4 protein forms a heterotetramer that underlies the cardiac acetylcholine-activated inwardly rectifying K + current, I KACh . Functional studies on human induced pluripotent stem cell–derived atrial cardiomyocytes showed that anti-K ir 3.4 IgG purified from patients with AF shortened action potentials and enhanced the constitutive form of I KACh , both key mediators of AF. To establish a causal relationship, we developed a mouse model of K ir 3.4 autoimmunity. Electrophysiological study in K ir 3.4-immunized mice showed that K ir 3.4 autoantibodies significantly reduced atrial effective refractory period and predisposed animals to a 2.8-fold increased susceptibility to AF. CONCLUSIONS: To our knowledge, this is the first report of an autoimmune pathogenesis of AF with direct evidence of K ir 3.4 autoantibody-mediated AF.

Antigen discovery by bioinformatics analysis and peptide microarray for the diagnosis of cystic echinococcosis

Batisti Biffignandi, Gherard; Vola, Ambra; Sassera, Davide; Najafi-Fard, Saeid; Gomez Morales, Maria Angeles; Brunetti, Enrico; Teggi, Antonella; Goletti, Delia; Petrone, Linda; Tamarozzi, Francesca
PLoS Negl Trop Dis.
Apr 2023
Background Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu lato, is a neglected zoonosis. Its diagnosis relies on imaging, supported by serology, while only imaging is useful for staging and follow-up. Since diagnostic tools and expertise are not widely available, new accurate and easily implementable assays for the diagnosis and follow-up of CE are highly needed. Methodology/Principal Findings We aimed to identify new E . granulosus antigens through a bioinformatics selection applied to the parasite genome, followed by peptide microarray screening and validation in ELISA, using independent panels of sera from patients with hepatic CE and clinically relevant controls. From 950 proteins selected in silico , 2,379 peptides were evaluated by microarray for IgG reactivity and eight candidates selected for validation. Reactivity to one peptide was significantly higher in the CE group (p = 0.044), but had suboptimal diagnostic accuracy. Conclusions/Significance Here we performed bioinformatics analysis and peptide microarray for antigen discovery, useful for the diagnosis of CE. Eight candidates were selected and validated. Reactivity to one peptide associated to CE but had suboptimal diagnostic accuracy. Importantly, the database developed in this study may be used to identify other antigenic candidates for CE diagnosis and follow-up.

Analysis of Plasmablasts from Children with Kawasaki Disease Reveals Evidence of a Convergent Antibody Response to a Specific Protein Epitope

Rowley, Anne H; Arrollo, David; Shulman, Stanford T; Torres, Abigail; O’Brien, Amornrat; Wylie, Kristine; Kim, Kwang-Youn A; Baker, Susan C
Abstract Background Kawasaki disease (KD) is a febrile illness of young childhood that can result in coronary artery aneurysms and death. COVID mitigation strategies resulted in a marked decrease in KD cases worldwide, supporting a transmissible respiratory agent as the cause. We previously reported a peptide epitope recognized by monoclonal antibodies (MAbs) derived from clonally expanded peripheral blood plasmablasts from 3 of 11 KD children, suggesting a common disease trigger in a subset of patients with KD. Methods We performed amino acid substitution scans to develop modified peptides with improved recognition by KD MAbs. We prepared additional MAbs from KD peripheral blood plasmablasts and assessed MAb characteristics that were associated with binding to the modified peptides. Results We report a modified peptide epitope that is recognized by 20 MAbs from 11 of 12 KD patients. These MAbs predominantly use heavy chain VH3-74; two-thirds of VH3-74 plasmablasts from these patients recognize the epitope. The MAbs were nonidentical between patients but share a common CDR3 motif. Conclusions These results demonstrate a convergent VH3-74 plasmablast response to a specific protein antigen in children with KD, supporting one predominant causative agent in the etiopathogenesis of the illness.

Human antibody profiling technologies for autoimmune disease

Carlton, Lauren H.; McGregor, Reuben; Moreland, Nicole J.
Immunol Res.
Jan 2023
Abstract Autoimmune diseases are caused by the break-down in self-tolerance mechanisms and can result in the generation of autoantibodies specific to human antigens. Human autoantigen profiling technologies such as solid surface arrays and display technologies are powerful high-throughput technologies utilised to discover and map novel autoantigens associated with disease. This review compares human autoantigen profiling technologies including the application of these approaches in chronic and post-infectious autoimmune disease. Each technology has advantages and limitations that should be considered when designing new projects to profile autoantibodies. Recent studies that have utilised these technologies across a range of diseases have highlighted marked heterogeneity in autoantibody specificity between individuals as a frequent feature. This individual heterogeneity suggests that epitope spreading maybe an important mechanism in the pathogenesis of autoimmune disease in general and likely contributes to inflammatory tissue damage and symptoms. Studies focused on identifying autoantibody biomarkers for diagnosis should use targeted data analysis to identify the rarer public epitopes and antigens, common between individuals. Thus, utilisation of human autoantigen profiling technology, combined with different analysis approaches, can illuminate both pathogenesis and biomarker discovery.

Antibody Properties Associate with Clinical Phenotype in LGI1 Encephalitis

Ludewig, Susann; Salzburger, Leonie; Goihl, Alexander; Rohne, Jana; Leypoldt, Frank; Bittner, Daniel; Düzel, Emrah; Schraven, Burkhart; Reinhold, Dirk; Korte, Martin; Körtvélyessy, Péter
Cells.
Jan 2023
Autoimmune encephalitis (AE) associated with autoantibodies against leucine-rich glioma-inactivated protein-1 (LGI1) can present with faciobrachial dystonic seizures (FBDS) and/or limbic encephalitis (LE). The reasons for this heterogeneity in phenotypes are unclear. We performed autoantibody (abs) characterization per patient, two patients suffering from LE and two from FBDS, using isolated antibodies specified with single amino acid epitope mapping. Electrophysiological slice recordings were conducted alongside spine density measurements, postsynaptic Alpha-amino-3-hydoxy-5-methyl-4-isoaxole-proprionate-receptors (AMPA-R) and N-methyl-D-aspartate-receptors receptor (NMDA-R) cluster counting. These results were correlated with the symptoms of each patient. While LGI1 abs from LE patients mainly interacted with the Leucine-rich repeat section of LGI1, abs from both FBDS patients also recognized the Epitempin section as well. Six-hour incubation of mouse hippocampal slices with LE patients autoantibodies but not from the FBDS patients resulted in a significant decline in long-term potentiation (p = 0.0015) or short-term plasticity at CA3-CA1 neurons and in decreased hippocampal synaptic density. Cluster differentiation showed no decrease in postsynaptic AMPA-R and NMDA-R. LGI1 autoantibodies selected by phenotype show an almost distinct epitope pattern, elicit disparate functional effects on hippocampal neurons, and cause divergent effects on spine density. This data illuminates potential pathomechanisms for disease heterogeneity in LGI1 AE.

Deciphering the Autoantibody Response to the OJ Antigenic Complex

Fritzler, Marvin J.; Bentow, Chelsea; Satoh, Minoru; McHugh, Neil; Ghirardello, Anna; Mahler, Michael
Diagnostics.
Jan 2023
(1) Background: Myositis specific antibodies (MSA) are important diagnostic biomarkers. Among the rarest and most challenging MSA are anti-OJ antibodies which are associated with anti-synthetase syndrome (ASS). In contrast to the other tRNA synthetases that are targets of ASS autoantibodies (e.g Jo-1, PL-7, PL-12, EJ, KS, Zo), OJ represents a macromolecular complex with several ribonucleoprotein subunits. Therefore, the choice of the antigen in autoantibody assays can be challenging. (2) Methods: We collected two independent cohorts with anti-OJ antibodies, one based on a commercial line immunoassay (LIA) (n = 39), the second based on protein immunoprecipitation (IP) (n = 15). Samples were tested using a particle-based multi-analyte technology (PMAT) system that allows for the simultaneous detection of antibodies to various autoantigens. For the detection of anti-OJ antibodies, two different antigens were deployed (KARS, IARS) on PMAT. The reactivity to the two antigens KARS and IARS was analyzed individually and combined in a score (sum of the median fluorescence intensities). (3) Results: In the cohort selection based on LIA, 3/39 (7.7%) samples were positive for anti-KARS and 7/39 (17.9%) for anti-IARS and 14/39 (35.9%) when the two antigens were combined. In contrast, in samples selected by IP the sensitivity of anti-KARS was higher: 6/15 (40.0%) samples were positive for anti-KARS, 4/15 (26.7%) for anti-IARS and 12/15 (80.0%) for the combination of the two antigens. 18/39 (46.2%) of the LIA samples generated a cytoplasmic IIF pattern (compatible with anti-synthetase antibodies), but there was no association with the antibody levels, neither with LIA nor with PMAT. (4) Conclusions: The combination of IARS and KARS might represent a promising approach for the detection of anti-OJ antibodies on a fully automated platform.

Compounds and Methods Targeting Interleukin-19

Higgs Jr., Richard Earl; Konrad, Robert John; Nickoloff, Brian Jeffrey; Siegel II, Robert William; Mertz, Prema Maria
Nov 2020
The present invention provides compounds and methods targeting human interleukin-19, including therapeutic antibodies, pharmaceutical compositions and diagnostic applications useful in the field of immune-mediated diseases including psoriasis, atopic dermatitis, psoriatic arthritis, bronchial asthma and diabetic nephropathy.

Novel Anti-Cd40 Antibodies and Use Thereof

Park, Chung Gyu; Kim, Jung Sik; Lucas, Zachariah
Sep 2020
The present invention relates to novel anti-CD40 antibodies and a use thereof and, more specifically, provided are a pharmaceutical composition for treating or preventing autoimmune diseases and a composition for inhibiting immune rejection during organ transplantation, both compositions containing, as an active ingredient, novel anti-CD40 antibodies that specifically bind to a novel epitope of CD40. Novel anti-CD40 antibodies of the present invention directly target CD40, but not CD40 ligands, and block the signaling of CD40-CD154 without stimulating platelets so as to exhibit excellent antagonistic effects, thereby being expected to be usable as a preparation effective in the treatment of autoimmune diseases and the inhibition of organ transplantation rejection.

Rapid response to pandemic threats: immunogenic epitope detection of pandemic pathogens for diagnostics and vaccine development using peptide microarrays

Heiss, Kirsten; Heidepriem, Jasmin; Fischer, Nico; Weber, Laura K; Dahlke, Christine; Jaenisch, Thomas; Loeffler, Felix F
J. Proteome Res..
Sep 2020
Emergence and re-emergence of pathogens bearing the risk of becoming a pandemic threat are on the rise. Increased travel and trade, growing population density, changes in urbanization, and climate have a critical impact on infectious disease spread. Currently, the world is confronted with the emergence of a novel coronavirus SARS-CoV-2, responsible for yet more than 500 000 deaths globally. Outbreaks caused by viruses such as SARS-CoV-2, HIV, Ebola, influenza, and Zika have increased over the last decade, underlining the urgent need for a rapid development of diagnostics and vaccines. Hence, the rational identification of biomarkers for diagnostic measures on the one hand, and antigenic targets for vaccine development on the other, are of utmost importance. Peptide microarrays can display large numbers of putative target proteins translated into overlapping linear (and cyclic) peptides. Using these highly diverse libraries, covering tens of thousands of peptides, allow for the in-depth analysis of antibody signatures in a multiplexed, high-throughput fashion. In this review, we highlight synthesis platforms that facilitate fast and highly flexible generation of high-density peptide microarrays. We further outline the multifaceted applications of these peptide array platforms for the development of serological tests and vaccines, to quickly encounter pandemic threats.

On‐Chip Neo‐Glycopeptide Synthesis for Multivalent Glycan Presentation

Mende, Marco; Tsouka, Alexandra; Heidepriem, Jasmin; Paris, Grigori; Mattes, Daniela S.; Eickelmann, Stephan; Bordoni, Vittorio; Wawrzinek, Robert; Fuchsberger, Felix F.; Seeberger, Peter H.; Rademacher, Christoph; Delbianco, Martina; Mallagaray, Alvaro; Loeffler, Felix F
Chem. Eur. J..
Apr 2020
Single glycan–protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry, neo-glycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding.

Bayesian Analysis of MicroScale Thermophoresis Data to Quantify Affinity of Protein:Protein Interactions with Human Survivin

Garcia-Bonete, Maria-Jose; Jensen, Maja; Recktenwald, Christian V.; Rocha, Sandra; Stadler, Volker; Bokarewa, Maria; Katona, Gergely
Sci Rep.
Dec 2017
A biomolecular ensemble exhibits different responses to a temperature gradient depending on its diffusion properties. MicroScale Thermophoresis technique exploits this effect and is becoming a popular technique for analyzing interactions of biomolecules in solution. When comparing affinities of related compounds, the reliability of the determined thermodynamic parameters often comes into question. The thermophoresis binding curves can be assessed by Bayesian inference, which provides a probability distribution for the dissociation constant of the interacting partners. By applying Bayesian machine learning principles, binding curves can be autonomously analyzed without manual intervention and without introducing subjective bias by outlier rejection. We demonstrate the Bayesian inference protocol on the known survivin:borealin interaction and on the putative protein-protein interactions between human survivin and two members of the human Shugoshin-like family (hSgol1 and hSgol2). These interactions were identified in a protein microarray binding assay against survivin and confirmed by MicroScale Thermophoresis.

Antibody fingerprints in lyme disease deciphered with high density peptide arrays

Weber, Laura K.; Isse, Awale; Rentschler, Simone; Kneusel, Richard E.; Palermo, Andrea; Hubbuch, Jürgen; Nesterov-Mueller, Alexander; Breitling, Frank; Loeffler, Felix F.
Eng. Life Sci..
Oct 2017
Lyme disease is the most common tick-borne infectious disease in Europe and North America. Previous studies discovered the immunogenic role of a surface-exposed lipoprotein (VlsE) of Borreliella burgdorferi. We employed high density peptide arrays to investigate the antibody response to the VlsE protein in VlsE-positive patients by mapping the protein as overlapping peptides and subsequent in-depth epitope substitution analyses. These investigations led to the identification of antibody fingerprints represented by a number of key residues that are indispensable for the binding of the respective antibody. This approach allows us to compare the antibody specificities of different patients to the resolution of single amino acids. Our study revealed that the sera of VlsE-positive patients recognize different epitopes on the protein. Remarkably, in those cases where the same epitope is targeted, the antibody fingerprint is almost identical. Furthermore, we could correlate two fingerprints with human autoantigens and an Epstein-Barr virus epitope; yet, the link to autoimmune disorders seems unlikely and must be investigated in further studies. The other three fingerprints are much more specific for B. burgdorferi. Since antibody fingerprints of longer sequences have proven to be highly disease specific, our findings suggest that the fingerprints could function as diagnostic markers that can reduce false positive test results.

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