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

Integrative proteomics, genomics, and translational immunology approaches reveal mutated forms of Proteolipid Protein 1 (PLP1) and mutant-specific immune response in multiple sclerosis

Qendro, Veneta; Bugos, Grace A.; Lundgren, Debbie H.; Glynn, John; Han, May H.; Han, David K.
Proteomics.
Mar 2017
In order to gain mechanistic insights into multiple sclerosis (MS) pathogenesis, we utilized a multi-dimensional approach to test the hypothesis that mutations in myelin proteins lead to immune activation and central nervous system autoimmunity in MS. Mass spectrometry-based proteomic analysis of human MS brain lesions revealed seven unique mutations of PLP1; a key myelin protein that is known to be destroyed in MS. Surprisingly, in-depth genomic analysis of two MS patients at the genomic DNA and mRNA confirmed mutated PLP1 in RNA, but not in the genomic DNA. Quantification of wild type and mutant PLP RNA levels by qPCR further validated the presence of mutant PLP RNA in the MS patients. To seek evidence linking mutations in abundant myelin proteins and immune-mediated destruction of myelin, specific immune response against mutant PLP1 in MS patients was examined. Thus, we have designed paired, wild type and mutant peptide microarrays, and examined antibody response to multiple mutated PLP1 in sera from MS patients. Consistent with the idea of different patients exhibiting unique mutation profiles, we found that 13 out of 20 MS patients showed antibody responses against specific but not against all the mutant-PLP1 peptides. Interestingly, we found mutant PLP-directed antibody response against specific mutant peptides in the sera of pre-MS controls. The results from integrative proteomic, genomic, and immune analyses reveal a possible mechanism of mutation-driven pathogenesis in human MS. The study also highlights the need for integrative genomic and proteomic analyses for uncovering pathogenic mechanisms of human diseases.

Acquired Factor XIII inhibitor associated with mantle cell lymphoma: ACQUIRED FXIII INHIBITOR

Nixon, Christian P.; Prsic, Elizabeth H.; Guertin, Christine A.; Stevenson, Ryan L.; Sweeney, Joseph D.
Transfusion.
Mar 2017
BACKGROUND Acquired Factor (F)XIII deficiency is a very rare bleeding diathesis with a potentially fatal outcome, previously described in the context of autoimmune disorders and leukemias. There is minimal information on autoantibody characterization and the role of antifibrinolytic therapy in patient management. CASE REPORT A 79-year-old woman with a 3-month history of bruising and heavy menorrhagia presented with ongoing vaginal bleeding, symptomatic anemia, and a right thigh hematoma. Initial management included an axillary lymph node biopsy and coagulation evaluation. Pathologic examination of the biopsy specimen revealed mantle cell lymphoma. Clot solubility assay was consistent with a FXIII activity of less than 3%. An anti-FXIII inhibitor was suspected, the epitope specificity of which was mapped by micropeptide array analysis to regions in the β-sandwich and catalytic core domain of the FXIII-A subunit. Management with cryoprecipitate, steroids, rituximab, and antifibrinolytic therapy resolved the bleeding diathesis and suppressed the inhibitor. CONCLUSION This is the first reported case of an acquired FXIII inhibitor associated with mantle cell lymphoma in which the epitope specificity of the pathologic autoantibody was accurately defined. Antifibrinolytic therapy played a prominent role in the prevention of bleeding complications in the window period between initiation of immunosuppression and disappearance of the pathologic anti-FXIII autoantibody.

Autoantikehad täppismeditsiinis

Jaks, Viljar; Uibo, Raivo
Immuuntolerantsi häirumine, mille üheks väljundiks on antikehade teke organismile omaste biomolekulide vastu, on oluline patogeneetiline mehhanism mitmete laialdaselt levinud haiguste puhul ja seetõttu on autoantikehade määramine kujunenud oluliseks diagnostiliseks vahendiks. Artiklis on käsitletud autoantikehade esinemise olulisust haiguste tekke ja kulu prognoosimisel. Kuigi sellekohane info on veel üsna napp, on selge, et organismi immuunstaatuse muutus eelneb aastaid haiguse ilmnemisele ning autoimmuunset komponenti sisaldava haiguse kulg ja prognoos on seotud patsiendil esinevate kindlate autoantikehadega. Sellest tulenevalt võime loota, et organismi immuunstaatuse uurimine, eriti aga autoantikehade spektri iseloomustamine, on tulevikus geneetilise info analüüsimise kõrval üks täppismeditsiini olulisemaid tööriistu.

Combination of two epitope identification techniques enables the rational design of soy allergen Gly m 4 mutants

Havenith, Heide; Kern, Karolin; Rautenberger, Paul; Spiegel, Holger; Szardenings, Michael; Ueberham, Elke; Lehmann, Jörg; Buntru, Matthias; Vogel, Simon; Treudler, Regina; Fischer, Rainer; Schillberg, Stefan
Biotechnol. J..
Feb 2017
Detailed IgE-binding epitope analysis is a key requirement for the understanding and development of diagnostic and therapeutic agents to address food allergies. An IgE-specific linear peptide microarray with random phage peptide display for the high-resolution mapping of IgE-binding epitopes of the major soybean allergen Gly m 4, which is a homologue to the birch pollen allergen Bet v 1 is combined. Three epitopes are identified and mapped to a resolution of four key amino acids, allowing the rational design and the production of three Gly m 4 mutants with the aim to abolish or reduce the binding of epitope-specific IgE. In ELISA, the binding of the mutant allergens to polyclonal rabbit-anti Gly m 4 serum as well as IgE purified from Gly m 4-reactive soybean allergy patient sera is reduced by up to 63% compared to the wild-type allergen. Basophil stimulation experiments using RBL-SX38 cells loaded with patient IgE are showed a decreased stimulation from 25% for the wild-type Gly m 4 to 13% for one mutant. The presented approach demonstrates the feasibility of precise mapping of allergy-related IgE-binding epitopes, allowing the rational design of less allergenic mutants as potential therapeutic agents.

Antibody repertoire profiling with mimotope arrays

Pashova, Shina; Schneider, Christoph; von Gunten, Stephan; Pashov, Anastas
Human Vaccines & Immunotherapeutics.
Jan 2017
Large-scale profiling and monitoring of antibody repertoires is possible through next generation sequencing (NGS), phage display libraries and microarrays. These methods can be combined in a pipeline, which ultimately maps the antibody reactivities onto defined arrays of structures – peptides or carbohydrates. The arrays can help analyze the individual specificities or can be used as complex patterns. In any case, the targets recognized should formally be considered mimotopes unless they are proven to be epitopes driving the antibody synthesis. Here, the advantages and disadvantages of the major profiling techniques as well as their current and future application in disease prediction and vaccination are discussed.

Identification of three immunodominant motifs with atypical isotype profile scattered over the Onchocerca volvulus proteome

Lagatie, Ole; Van Dorst, Bieke; Stuyver, Lieven J.
PLoS Negl Trop Dis.
Jan 2017
Understanding the immune response upon infection with the filarial nematode Onchocerca volvulus and the mechanisms that evolved in this parasite to evade immune mediated elimination is essential to expand the toolbox available for diagnostics, therapeutics and vaccines development. Using high-density peptide microarrays we scanned the proteome-wide linear epitope repertoire in Cameroonian onchocerciasis patients and healthy controls from Southern Africa which led to the identification of 249 immunodominant antigenic peptides. Motif analysis learned that 3 immunodominant motifs, encompassing 3 linear epitopes, are present in 70, 43, and 31 of these peptides, respectively and appear to be scattered over the entire proteome in seemingly non-related proteins. These linear epitopes are shown to have an atypical isotype profile dominated by IgG1, IgG3, IgE and IgM, in contrast to the commonly observed IgG4 response in chronic active helminth infections. The identification of these linear epitope motifs may lead to novel diagnostic development but further evaluation of cross-reactivity against common co-infecting human nematode infections will be needed.

Functional screening for anti-CMV biologics identifies a broadly neutralizing epitope of an essential envelope protein

Gardner, Thomas J.; Stein, Kathryn R.; Duty, J. Andrew; Schwarz, Toni M.; Noriega, Vanessa M.; Kraus, Thomas; Moran, Thomas M.; Tortorella, Domenico
Nat Commun.
Dec 2016
The prototypic β-herpesvirus human cytomegalovirus (CMV) establishes life-long persistence within its human host. The CMV envelope consists of various protein complexes that enable wide viral tropism. More specifically, the glycoprotein complex gH/gL/gO (gH-trimer) is required for infection of all cell types, while the gH/gL/UL128/130/131a (gH-pentamer) complex imparts specificity in infecting epithelial, endothelial and myeloid cells. Here we utilize state-of-the-art robotics and a high-throughput neutralization assay to screen and identify monoclonal antibodies (mAbs) targeting the gH glycoproteins that display broad-spectrum properties to inhibit virus infection and dissemination. Subsequent biochemical characterization reveals that the mAbs bind to gH-trimer and gH-pentamer complexes and identify the antibodies’ epitope as an ‘antigenic hot spot’ critical for virus entry. The mAbs inhibit CMV infection at a post-attachment step by interacting with a highly conserved central alpha helix-rich domain. The platform described here provides the framework for development of effective CMV biologics and vaccine design strategies.

Identification of novel antigens contributing to autoimmunity in cardiovascular diseases

Müller, Anna-Maria; Bockstahler, Mariella; Hristov, Georgi; Weiß, Christel; Fischer, Andrea; Korkmaz-Icöz, Sevil; Giannitsis, Evangelos; Poller, Wolfgang; Schultheiss, Heinz-Peter; Katus, Hugo A.; Kaya, Ziya
Clinical Immunology.
Dec 2016
In myocarditis and dilated cardiomyopathy (DCM) patients the immune system may play an important role in disease progression. In this study, we aimed to identify new antigens as a target for autoimmune response that might play a crucial role in these diseases. Therefore, a peptide-array was used to investigate antibody binding profiles in patients with autoimmune myocarditis or DCM compared to healthy controls and thus to identify disease relevant antigens. To analyze the pathogenicity of the identified antigens, an experimental autoimmune myocarditis (EAM) model was used. Hereby, 3 peptide sequences, derived from myosin-binding-protein-C (MYBPC) fast-type, RNA-binding-protein 20 (RBM20), and dystrophin, showed pathogenic effects on the myocardium of mice. In summary, 3 potentially cardiopathogenic peptides (MYBPC fast-type, RBM20, dystrophin) were identified. Thus, this study could serve as a basis for future investigations aimed at determining further antigens leading to pathogenic effects on the myocardium of DCM as well as myocarditis patients.

Antibody Binding Studies Reveal Conformational Flexibility of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) A-Component

Didier, A.; Dietrich, R.; Märtlbauer, E.
PLoS ONE.
Oct 2016
The non-hemolytic enterotoxin complex (Nhe) is supposed to be the main virulence factor of B. cereus causing a diarrheal outcome of food poisoning. This tripartite toxin consists of the single components NheA, -B and -C all of them being necessary for maximum toxicity. In the past, research activities aiming to elucidate the mode-of-action of Nhe were mostly focused on the B- and C-component. In this study the generation of novel monoclonal antibodies (mAb) and their thorough characterization enabled the determination of key features for NheA. By the means of immunoaffinity chromatography it could be shown that NheA does not interact with -B and -C in solution. Additionally, the establishment of a highly sensitive sandwich-EIA now enables the detection of NheA in B. cereus supernatants down to 20 pg ml-1.Peptide-based epitope mapping in combination with partially deleted recombinant NheA fragments allowed the allocation of the binding regions for the three mAbs under study. Furthermore, by different EIA set-ups the conformational flexibility of NheA could be shown. For two of the antibodies under study different mechanisms of NheA neutralization were proven. Due to prevention of complete pore formation by one of the antibodies, NheA could be detected in an intermediate stage of the tripartite complex on the cell surface. Taken together, the results obtained in the present study allow a refinement of the mode-of-action for the Nhe toxin-complex.

A single amino acid substitution alter antigenicity of Glycosylated protein 4 of HP-PRRSV

Wang, Xinglong; Wang, Zhenbin; Xu, Hongyu; Biao, Xiang; Yang, Zengqi
Virol J.
Jul 2016
Background Porcine reproductive and respiratory syndrome (PRRS) is an important pig endemic disease in pork-producing countries worldwide. The etiology, porcine reproductive and respiratory syndrome virus (PRRSV), is characterized by fast antigen variability. Glycosylated protein 4 (GP4) is a minor protein in PRRSV virion, but contributes to induce protective immune responses. However, the antigenic characterization of PRRSV GP4 and the role of the mutations in this protein in PRRSV evolution are not clear. Methods Peptides chip scanning and peptide based ELISA was used to analyze the antigenic characterization of HP-PRRSV GP4. A total of 142 peptides printed on a chip were used to reveal the antigen reaction characteristics of the HP-PRRSV. The reactions of these peptides with HP-PRRSV-specific pig serum were scanned and quantified using the software PepSlide® Analyzer by fluorescence intensity. The active reaction regions (AR) were identified based on the scanning results and then the amino acids (aa) sequences of AR(s) is aligned among PRRSV strains for further identify the key aa site(s) impact the antigenicity of the protein. Peptide based ELISA is then reacted with PRRSV positive sera derived from pig inoculated with different PRRSV strains for further analysis the role of specific amino acid in AR. Results The intensity plot was used to show the reactions of the peptides with PRRSV serum and it showed that enormously different response happened to various parts of GP4. The highest reaction intensity value reached 6401.5 against one peptide with the sequence DIKTNTTAASDFVVL. An AR from S29 to G56 was identified. Sequence alignment revealed various mutations in site 43 and possibly played an important role in this AR. Peptides ELISA reaction with sera from pigs inoculated with different PRRSV strain revealed that the change of aa in site 43 reduced the reaction of the peptide with PRRSV positive sera derived from pigs inoculated with the peptide related PRRSV strains. Conclusion In this study, one AR covering S29 to G56 was identified in GP4. The aa in site 43 play an important role in determining the antigenic character of GP4. The continual mutations (S → G → D → N) occurred in this site alter the antigenicity of PRRSV GP4.

Properties of Two Enterovirus Antibodies that are Utilized in Diabetes Research

Maccari, Giuseppe; Genoni, Angelo; Sansonno, Silvia; Toniolo, Antonio
Sci Rep.
Apr 2016
Human enteroviruses (EVs) comprise >100 different types. Research suggests a non-chance association between EV infections and type 1 diabetes. Immunohistochemical studies with the anti-EV antibody 5D-8.1 have shown that the EV capsid antigen is present in pancreatic islet cells of diabetic subjects. When it was noticed that 5D-8.1 may cross-react with human proteins, doubt was casted on the significance of the above histopathologic findings. To address this issue, properties of EV antibodies 5D-8.1 and 9D5 have been investigated using peptide microarrays, peptide substitution scanning, immunofluorescence of EV-infected cells, EV neutralization assays, bioinformatics analysis. Evidence indicates that the two antibodies bind to distinct non-neutralizing linear epitopes in VP1 and are specific for a vast spectrum of EV types (not for other human viruses). However, their epitopes may align with a few human proteins at low expected values. When tested by immunofluorescence, high concentrations of 5D-8.1 yelded faint cytoplasmic staining in uninfected cells. At reduced concentrations, both antibodies produced dotted staining only in the cytoplasm of infected cells and recognized both acute and persistent EV infection. Thus, the two monoclonals represent distinct and independent probes for hunting EVs in tissues of patients with diabetes or other endocrine conditions.

High-Density Peptide Arrays for Malaria Vaccine Development

Loeffler, Felix F.; Pfeil, Johannes; Heiss, Kirsten
The development of an efficacious and practicable vaccine conferring sterile immunity towards a Plasmodium infection represents a not yet achieved goal. A crucial factor for the impact of a given anti-plasmodial subunit vaccine is the identification of the most potent parasitic components required to induce protection from both infection and disease. Here, we present a method based on a novel high-density peptide array technology that allows for a flexible readout of malaria antibodies. Peptide arrays applied as a screening method can be used to identify novel immunogenic antibody epitopes under a large number of potential antigens/peptides. Ultimately, discovered antigen candidates and/or epitope sequences can be translated into vaccine prototype design. The technology can be further utilized to unravel antibody-mediated immune responses (e.g., involved in the establishment of semi-immunity) and moreover to confirm vaccine potency during the process of clinical development by verifying the induced antibody responses following vaccination.

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