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

Diagnostic Profiling of the Human Public IgM Repertoire With Scalable Mimotope Libraries

Pashov, Anastas; Shivarov, Velizar; Hadzhieva, Maya; Kostov, Victor; Ferdinandov, Dilyan; Heintz, Karen-Marie; Pashova, Shina; Todorova, Milena; Vassilev, Tchavdar; Kieber-Emmons, Thomas; Meza-Zepeda, Leonardo A.; Hovig, Eivind
Front. Immunol..
Dec 2019
Specific antibody reactivities are routinely used as biomarkers, but the antibody repertoire reactivity (igome) profiles are still neglected. Here, we propose rationally designed peptide arrays as efficient probes for these system level biomarkers. Most IgM antibodies are characterized by few somatic mutations, polyspecificity, and physiological autoreactivity with housekeeping function. Previously, probing this repertoire with a set of immunodominant self-proteins provided a coarse analysis of the respective repertoire profiles. In contrast, here, we describe the generation of a peptide mimotope library that reflects the common IgM repertoire of 10,000 healthy donors. In addition, an appropriately sized subset of this quasi-complete mimotope library was further designed as a potential diagnostic tool. A 7-mer random peptide phage display library was panned on pooled human IgM. Next-generation sequencing of the selected phage yielded 224,087 sequences, which clustered in 790 sequence clusters. A set of 594 mimotopes, representative of the most significant sequence clusters, was shown to probe symmetrically the space of IgM reactivities in patients’ sera. This set of mimotopes can be easily scaled including a greater proportion of the mimotope library. The trade-off between the array size and the resolution can be explored while preserving the symmetric sampling of the mimotope sequence and reactivity spaces. BLAST search of the non-redundant protein database with the mimotopes sequences yielded significantly more immunoglobulin J region hits than random peptides, indicating a considerable idiotypic connectivity of the targeted igome. The proof of principle predictors for random diagnoses was represented by profiles of mimotopes. The number of potential reactivity profiles that can be extracted from this library is estimated at more than 1070. Thus, a quasi-complete IgM mimotope library and a scalable representative subset thereof are found to address very efficiently the dynamic diversity of the human public IgM repertoire, providing informationally dense and structurally interpretable IgM reactivity profiles.

A Low‐Cost Laser‐Based Nano‐3D Polymer Printer for Rapid Surface Patterning and Chemical Synthesis of Peptide and Glycan Microarrays

Eickelmann, Stephan; Tsouka, Alexandra; Heidepriem, Jasmin; Paris, Grigori; Zhang, Junfang; Molinari, Valerio; Mende, Marco; Loeffler, Felix F.
Adv. Mater. Technol..
Nov 2019
A low-cost laser-based printing setup is presented, which allows for the spot-wise patterning of surfaces with defined polymer nanolayers. These nanolayer spots serve as a “solid solvent,” embedding different chemicals, chemical building blocks, materials, or precursors and can be stacked on top of each other. By melting the spot pattern, the polymer-embedded molecules are released for chemical reaction. This enables researchers to quickly pattern a surface with different molecules and materials, mixing them directly on the surface for high-throughput chemical synthesis to generate and screen diverse microarray libraries. In contrast to expensive ink-jet or contact printing, this approach does not require premixing of inks, which enables in situ combinatorial mixing. Easy access and versatility of this patterning approach are shown by generating microarrays of various biomolecules, such as glycans for the first time, to screen interactions of antibodies and lectins. In addition, a layer-by-layer solid-phase synthesis of peptides directly on the microarray is presented. Amino acid–containing nanolayers are repeatedly laser-transferred and reacted with the functionalized acceptor surface in defined patterns. This simple system enables a reproducible array production, down to spot-to-spot distances of 100 µm, and offers a flexible and cheap alternative to expensive spotting robot technology.

Ara h 7 isoforms share many linear epitopes: Are 3D epitopes crucial to elucidate divergent abilities?

Ehlers, Anna M.; Klinge, Marco; Suer, Waltraud; Weimann, Yvonne; Knulst, André C.; Besa, Frithjof; Le, Thuy‐My; Otten, Henny G.
Clin Exp Allergy.
Nov 2019
Background The peanut allergens Ara h 2, h 6, and h 7 are potent allergens and can trigger severe reactions. Ara h 7 consists of three isoforms differing in their ability to induce basophil degranulation, whereas the ability of Ara h 7.0201 is comparable to Ara h 2 and 6 as shown in previous literature. Objective To identify linear epitopes of Ara h 7.0101, Ara h 7.0201 and Ara h 7.0301 recognized by IgE and IgG4 from patients sensitized to Ara h 7 and to investigate their potential to elucidate divergent abilities of the Ara h 7 isoforms in inducing basophil activation. Methods Linear epitopes recognized by IgE and IgG4 were mapped by peptide microarray analysis containing 15-mer peptides of Ara h 2.0201, 6, 7.0101, 7.0201 and 7.0301 and 39 peanut allergic patients sensitized to Ara h 7 (discovery). For validation, 20-mer peptides containing the minimal epitope and surrounding amino acids were incubated with 25 sensitized patients and 10 controls (validation). Results Three out of 14 linear epitopes were unique for each isoform (Ara h 7.0101: aa 97-109; Ara h 7.0201: aa 122-133; Ara h 7.0301: aa 65-74) but scarcely recognized by IgE. The main linear IgE epitope (aa 51-57) located in the long flexible loop of all Ara h 7 isoforms was bound by antibodies from 31% of the patients (discovery and validation cohort). Regarding IgG4, 55% of the patients recognized an epitope present on all isoforms (aa 55-65), whereas epitope aa 129-137, only present on Ara h 7.0101/0.0301, was recognized by 38% of the patients. Recognition was highly individual, although 20% of the patients recognized any linear epitope neither by IgE nor by IgG4 despite a low mean z-score of ≥ 1.7. Remarkably, only 50% of the patients recognized one or more epitopes by IgE. Conclusion & Clinical Relevance Ara h 7 isoforms share many linear epitopes being easily accessible for antibody binding. Unique epitopes, essential to elucidate divergent potencies, were scarcely recognized, suggesting a crucial involvement of conformational epitopes.

Characterization of a sandwich ELISA for quantification of total human soluble neuropilin‐1

Gadermaier, Elisabeth; Tesarz, Manfred; Wallwitz, Jacqueline; Berg, Gabriela; Himmler, Gottfried
J Clin Lab Anal.
Sep 2019
Background Neuropilin-1 (NRP1) is a highly interactive molecule that exists as transmembrane and soluble isoforms. Measurement of circulating levels of soluble NRP1 (sNRP1) in human serum and plasma has proven to be difficult due to present matrix interferences and due to the lack of a reliable technique. Methods We developed a highly specific and sensitive sandwich ELISA assay for total sNRP1 quantification in peripheral blood, and we validated the test according to ICH guidelines. The linear epitopes of the employed polyclonal and monoclonal anti-human NRP1 antibodies were mapped with microarray technology. We included a sample pre-treatment step with guanidine hydrochloride (GuHCl) to release sNRP1 from existing interferants. Results The ELISA assay which is calibrated with sNRP1 isoform 2 and covers a calibration range from 0.375 to 12 nmol/L detects sNRP1 in human serum and plasma (heparin, EDTA, and citrate). Multiple linear epitopes recognized by the polyclonal coating antibody are distributed over the whole sNRP1 sequence. The monoclonal detection antibody binds to a linear epitope which is in the N-terminal region of the a1 domain of human sNRP1. Assay parameters like precision (intra-assay: 6%), dilution linearity (95%-115%), specificity (98%), and spike recovery (81%-109%) meet the international standards of acceptance. Conclusion Our novel sandwich ELISA provides a reliable tool for the quantitative determination of total human sNRP1. The assay detects free and previous ligand-bound total NRP1.

Immunization of cats to induce neutralizing antibodies against Fel d 1, the major feline allergen in human subjects

Thoms, Franziska; Jennings, Gary T.; Maudrich, Melanie; Vogel, Monique; Haas, Stefanie; Zeltins, Andris; Hofmann-Lehmann, Regina; Riond, Barbara; Grossmann, Jonas; Hunziker, Peter; Fettelschoss-Gabriel, Antonia; Senti, Gabriela; Kündig, Thomas M.; Bachmann, Martin F.
Journal of Allergy and Clinical Immunology.
Jul 2019
Background Cat allergy in human subjects is usually caused by the major cat allergen Fel d 1 and is found in approximately 10% of the Western population. Currently, there is no efficient and safe therapy for cat allergy available. Allergic patients usually try to avoid cats or treat their allergy symptoms. Objective We developed a new strategy to treat Fel d 1–induced allergy in human subjects by immunizing cats against their own major allergen, Fel d 1. Methods A conjugate vaccine consisting of recombinant Fel d 1 and a virus-like particle derived from the cucumber mosaic virus containing the tetanus toxin–derived universal T-cell epitope tt830-843 (CuMVTT) was used to immunize cats. A first tolerability and immunogenicity study, including a boost injection, was conducted by using the Fel-CuMVTT vaccine alone or in combination with an adjuvant. Results The vaccine was well tolerated and had no overt toxic effect. All cats induced a strong and sustained specific IgG antibody response. The induced anti–Fel d 1 antibodies were of high affinity and exhibited a strong neutralization ability tested both in vitro and in vivo. A reduction in the endogenous allergen level and a reduced allergenicity of tear samples, were observed. Conclusion Vaccination of cats with Fel-CuMVTT induces neutralizing antibodies and might result in reduced symptoms of allergic cat owners. Both human subjects and animals could profit from this treatment because allergic cat owners would reduce their risk of developing chronic diseases, such as asthma, and become more tolerant of their cats, which therefore could stay in the households and not need to be relinquished to animal shelters.

LRPAP1 is a frequent proliferation-inducing antigen of BCRs of mantle cell lymphomas and can be used for specific therapeutic targeting

Thurner, Lorenz; Hartmann, Sylvia; Fadle, Natalie; Kemele, Maria; Bock, Theresa; Bewarder, Moritz; Regitz, Evi; Neumann, Frank; Nimmesgern, Anna; von Müller, Lutz; Pott, Christiane; Kim, Yoo-Jin; Bohle, Rainer Maria; Wasik, Mariusz; Schuster, Stephen J.; Hansmann, Martin-Leo; Preuss, Klaus-Dieter; Pfreundschuh, Michael
Leukemia.
Jun 2019
The predominant usage of VH4-34 and V3-21 and reports of stereotyped CDR3s suggest a shared antigenic target of B-cell receptors (BCR) from mantle cell lymphomas (MCL). To identify the target antigens of MCL–BCRs, BCRs from 21 patients and seven MCL cell lines were recombinantly expressed and used for antigen screening. The BCRs from 8/21 patients and 2/7 MCL cell lines reacted specifically with the autoantigen low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1). High-titered and light chain-restricted anti-LRPAP1 serum antibodies were found in MCL patients, but not in controls. LRPAP1 induced proliferation by BCR pathway activation, while an LRPAP1–ETA′ toxin-conjugate specifically killed MCL cells with LRPAP1-specific BCRs. Our results suggest a role of LRPAP1 in lymphomagenesis and maintenance of a considerable proportion of MCL cases by chronic autoantigenic stimulation, likely evolving from a chronic autoreactive B-cell response. Importantly, LRPAP1 can be used for a novel therapeutic approach that targets MCL with LRPAP1-reactive BCRs with high specificity.

Miniaturized and Automated Synthesis of Biomolecules—Overview and Perspectives

Mattes, Daniela S.; Jung, Nicole; Weber, Laura K.; Bräse, Stefan; Breitling, Frank
Adv. Mater..
Jun 2019
Chemical synthesis is performed by reacting different chemical building blocks with defined stoichiometry, while meeting additional conditions, such as temperature and reaction time. Such a procedure is especially suited for automation and miniaturization. Life sciences lead the way to synthesizing millions of different oligonucleotides in extremely miniaturized reaction sites, e.g., pinpointing active genes in whole genomes, while chemistry advances different types of automation. Recent progress in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging could match miniaturized chemical synthesis with a powerful analytical tool to validate the outcome of many different synthesis pathways beyond applications in the life sciences. Thereby, due to the radical miniaturization of chemical synthesis, thousands of molecules can be synthesized. This in turn should allow ambitious research, e.g., finding novel synthesis routes or directly screening for photocatalysts. Herein, different technologies are discussed that might be involved in this endeavor. A special emphasis is given to the obstacles that need to be tackled when depositing tiny amounts of materials to many different extremely miniaturized reaction sites.

A high-sensitivity enzyme immunoassay for the quantification of soluble human semaphorin 4D in plasma

Laber, Anna; Gadermaier, Elisabeth; Wallwitz, Jacqueline; Berg, Gabriela; Himmler, Gottfried
Analytical Biochemistry.
Jun 2019
Human semaphorin 4D (SEMA4D), a type I integral membrane glycoprotein, regulates key cellular functions (e.g. cell-cell communication, platelet activation). Its 120 kDa extracellular region can be shed from the membrane to release soluble SEMA4D (sSEMA4D). Studies on circulating sSEMA4D levels are mostly performed with poorly characterized assays and use serum and plasma as matrix. We developed and validated a sandwich ELISA utilizing two monoclonal antibodies with resolved epitopes and determined affinities. Human serum and plasma samples were analyzed, and the influence of protease activity on sSEMA4D concentration was tested by collecting samples in the presence of the protease inhibitor TAPI-1. Both antibodies recognize conformational epitopes in the sema domain. Validation for plasma (EDTA, citrate, heparin) showed valid specificity, precision, accuracy, dilution linearity, and robustness. The assay shows a calibration range from 62.5 to 2000 pmol/L with a quantification limit of 31 pmol/L. sSEMA4D was significantly higher in serum than in plasma, whereas serum and plasma levels from samples collected in the presence of TAPI-1 showed no statistical difference. This ELISA provides a reliable tool for the quantification of sSEMA4D in human plasma. Serum is not recommended as matrix due to the accumulation of shed SEMA4D during blood coagulation altering serum sSEMA4D levels.

Active vaccination against interleukin-5 as long-term treatment for insect-bite hypersensitivity in horses

Fettelschoss-Gabriel, Antonia; Fettelschoss, Victoria; Olomski, Florian; Birkmann, Katharina; Thoms, Franziska; Bühler, Maya; Kummer, Martin; Zeltins, Andris; Kündig, Thomas M.; Bachmann, Martin F.
Allergy.
Mar 2019
Background Insect-bite hypersensitivity (IBH) in horses is a chronic allergic dermatitis caused by insect bites. Horses suffer from pruritic skin lesions, caused by type-I/type-IV allergic reactions accompanied by prominent eosinophil infiltration into the skin. Interleukin-5 (IL-5) is the key cytokine for eosinophils and we have previously shown that targeting IL-5 by vaccination reduces disease symptoms in horses. Objective Here, we analyzed the potential for long-term therapy by assessing a second follow-up year of the previously published study. Methods The vaccine consisted of equine IL-5 (eIL-5) covalently linked to a cucumber mosaic virus-like particle (VLP) containing a universal T cell epitope (CuMVTT) using a semi-crossover design to follow vaccinated horses during a second treatment season. Thirty Icelandic horses were immunized with 300 μg of eIL-5-CuMVTT without adjuvant. Results The vaccine was well tolerated and did not reveal any safety concerns throughout the study. Upon vaccination, all horses developed reversible anti-eIL-5 auto-antibody titers. The mean course of eosinophil levels was reduced compared to placebo treatment leading to significant reduction of clinical lesion scores. Horses in their second vaccination year showed a more pronounced improvement of disease symptoms when compared to first treatment year, most likely due to more stable antibody titers induced by a single booster injection. Hence, responses could be maintained over two seasons and the horses remained protected against disease symptoms. Conclusion Yearly vaccination against IL-5 may be a long-term solution for the treatment of IBH and other eosinophil-mediated diseases in horses and other species including humans.

Non-invasive glioblastoma immunoprofiling by printed peptide arrays

Mock, Andreas; Herold-Mende, Christel
OncoImmunology.
Feb 2016
Immune monitoring assays for patient stratification and treatment efficacy in clinical trials are in demand. We have recently described a cost-effective non-invasive assay to determine the immune status of glioblastoma patients. Profiling antitumor serum antibodies by customized printed peptide arrays identified response against a tenascin-C (TNC) peptide as a robust prognostic biomarker.

Autoantibodies specific to estrogen receptor alpha act as estrogen agonists and their levels correlate with breast cancer cell proliferation

Maselli, Angela; Capoccia, Sara; Pugliese, Patrizia; Raggi, Carla; Cirulli, Francesca; Fabi, Alessandra; Malorni, Walter; Pierdominici, Marina; Ortona, Elena
OncoImmunology.
Feb 2016
Estrogen receptors have recently been demonstrated at the cell surface. Unlike nuclear receptors, they are able to trigger rapid responses inside the cells. In this study, we evaluated the presence and the possible role of autoantibodies specific to estrogen receptor (anti-ER Abs) in the peripheral blood of breast cancer patients. Anti-ERα Abs were detectable in 22/48 (46%) patients’ sera and their levels positively correlated with the percentage of Ki-67-positive breast cancer cells. Anti-ERα Abs purified from breast cancer patients’ sera were able: (i) to recognize ERα epitopes expressed at the cell surface of ER-positive breast cancer cells, (ii) to trigger rapid extracellular signal-regulated kinase (ERK) phosphorylation, and (iii) to induce cell proliferation. Our results suggest that anti-ERα Abs can act as estrogen agonists playing a pathogenetic role as breast cancer-promoting factors. These autoantibodies could also be considered as possible peripheral blood biomarkers indicative of the breast cancer growth potential.

Purification and Characterization of Anacardium occidentale (Cashew) Allergens Ana o 1, Ana o 2, and Ana o 3

Reitsma, Marit; Bastiaan-Net, Shanna; Sforza, Stefano; van der Valk, Johanna P. M.; van Gerth van Wijk, Roy; Savelkoul, Huub F. J.; de Jong, Nicolette W.; Wichers, Harry J.
J. Agric. Food Chem..
Feb 2016
In this study a fast and simple purification procedure for the three known allergens from cashew (7S globulin Ana o 1, 11S globulin Ana o 2, and 2S albumin Ana o 3) is described. The purified allergens are characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, glycoprotein stain, and protein identification. The purified proteins still bind IgE, and this IgE binding varied between different pools of patient serum. Ana o 1 was found to be a glycoprotein. Ana o 3 has been studied more in detail to identify both the small and large subunits, both displaying microheterogeneity, and epitope mapping of Ana o 3 has been performed.

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