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

Epitope-Specific Anti-C1q Autoantibodies in Systemic Lupus Erythematosus

Kleer, Jessica S.; Rabatscher, Pascal A.; Weiss, Jessica; Leonardi, Joel; Vogt, Severin B.; Kieninger-Gräfitsch, Andrea; Chizzolini, Carlo; Huynh-Do, Uyen; Ribi, Camillo; Trendelenburg, Marten
Front. Immunol..
Jan 2022
Objective In patients with systemic lupus erythematosus (SLE) complement C1q is frequently targeted by autoantibodies (anti-C1q), that correlate best with active renal disease. Anti-C1q bind to largely unknown epitopes on the collagen-like region (CLR) of this highly functional molecule. Here we aimed at exploring the role of epitope-specific anti-C1q in SLE patients. Methods First, 22 sera of SLE patients, healthy controls and anti-C1q positive patients without SLE were screened for anti-C1q epitopes by a PEPperMAP® microarray, expressing CLR of C1q derived peptides with one amino acid (AA) shift in different lengths and conformations. Afterwards, samples of 378 SLE patients and 100 healthy blood donors were analyzed for antibodies against the identified epitopes by peptide-based ELISA. Relationships between peptide-specific autoantibodies and SLE disease manifestations were explored by logistic regression models. Results The epitope mapping showed increased IgG binding to three peptides of the C1q A- and three of the C1q B-chain. In subsequent peptide-based ELISAs, SLE sera showed significantly higher binding to two N-terminally located C1q A-chain peptides than controls (p < 0.0001), but not to the other peptides. While anti-C1q were associated with a broad spectrum of disease manifestations, some of the peptide-antibodies were associated with selected disease manifestations, and antibodies against the N-terminal C1q A-chain showed a stronger discrimination between SLE and controls than conventional anti-C1q. Conclusion In this large explorative study anti-C1q correlate with SLE overall disease activity. In contrast, peptide-antibodies are associated with specific aspects of the disease suggesting epitope-specific effects of anti-C1q in patients with SLE.

Protein microarrays for COVID-19 research: Biomarker discovery, humoral response, and vaccine targets

Acharjee, Arup; Barpanda, Abhilash; Ren, Jing; Yu, Xiaobo
Of all the technological interventions used to probe the COVID-19 biological sample, microarrays have provided unique information about the biology of SARS-CoV-2 infection in the greatest of detail. Protein microarrays are available in various formats such as protein microarray, antibody microarray, and peptide microarrays. These provide an attractive format to study host response against infection, with its straightforward sample preparation strategy and easy result analysis pipelines. Microarray technology either uses antibodies against hundreds of proteins to study host proteins or scans immunogenic peptides of the pathogen in a microarray panel of the pathogen proteome. It can be used to study the humoral immune response against antigenic proteins of the SARS-CoV-2 virus, host proteomic alterations due to the infection. The SARS-CoV-2 peptide array can be used for the accurate detection of antigenic determinants for vaccine design. This chapter summarizes the different types of protein and peptide microarray and their use in COVID-19 biomarker discovery, disease management, vaccine design, etc., for better management of COVID-19.

A Quantum Vaccinomics Approach Based on Protein–Protein Interactions

Contreras, Marinela; Artigas-Jerónimo, Sara; Pastor Comín, Juan J.; de la Fuente, José
Vaccines are the most effective preventive intervention to reduce the impact of infectious diseases worldwide. In particular, tick-borne diseases represent a growing burden for human and animal health worldwide and vaccines are the most effective and environmentally sound approach for the control of vector infestations and pathogen transmission. However, the development of effective vaccines for the control of tick-borne diseases with combined vector-derived and pathogen-derived antigens is one of the limitations for the development of effective vaccine formulations. Quantum biology arise from findings suggesting that living cells operate under non-trivial features of quantum mechanics, which has been proposed to be involved in DNA mutation biological process. Then, the electronic structure of the molecular interactions behind peptide immunogenicity led to quantum immunology and based on the definition of the photon as a quantum of light, the immune protective epitopes were proposed as the immunological quantum. Recently, a quantum vaccinomics approach was proposed based on the characterization of the immunological quantum to further advance the design of more effective and safe vaccines. In this chapter, we describe methods of the quantum vaccinomics approach based on proteins with key functions in cell interactome and regulome of vector–host–pathogen interactions for the identification by yeast two-hybrid screen and the characterization by in vitro protein–protein interactions and musical scores of protein interacting domains, and the characterization of conserved protective epitopes in protein interacting domains. These results can then be used for the design and production of chimeric protective antigens.

Spot peptide arrays and SPR measurements: throughput and quantification in antibody selectivity studies: Peptide Arrays for Antibody Selectivity Studies

Vernet, Thierry; Choulier, Laurence; Nominé, Yves; Bellard, Laure; Baltzinger, Mireille; Travé, Gilles; Altschuh, Danièle
J. Mol. Recognit..
Oct 2015
Antibody selectivity represents a major issue in the development of efficient immuno-therapeutics and detection assays. Its description requires a comparison of the affinities of the antibody for a significant number of antigen variants. In the case of peptide antigens, this task can now be addressed to a significant level of details owing to improvements in spot peptide array technologies. They allow the high-throughput mutational analysis of peptides with, depending on assay design, an evaluation of binding stabilities. Here, we examine the cross-reactive capacity of an antibody fragment using the PEPperCHIP® technology platform (PEPperPRINT GmbH, Heidelberg, Germany; >8800 peptides per microarray) combined with the surface plasmon resonance characterization (Biacore® technology; GE-Healthcare Biacore, Uppsala, Sweden) of a subset of interactions. ScFv1F4 recognizes the N-terminal end of oncoprotein E6 of human papilloma virus 16. The spot permutation analysis (i.e. each position substituted by all amino acids except cysteine) of the wild type decapeptide (sequence 6TAMFQDPQER15) and of 15 variants thereof defined the optimal epitope and provided a ranking for variant recognition. The SPR affinity measurements mostly validated the ranking of complex stabilities deduced from array data and defined the sensitivity of spot fluorescence intensities, bringing further insight into the conditions for cross-reactivity. Our data demonstrate the importance of throughput and quantification in the assessment of antibody selectivity.

General Approach for Tetramer-Based Identification of Autoantigen-Reactive B Cells: Characterization of La- and snRNP-Reactive B Cells in Autoimmune BXD2 Mice

Hamilton, Jennie A.; Li, Jun; Wu, Qi; Yang, PingAr; Luo, Bao; Li, Hao; Bradley, John E.; Taylor, Justin J.; Randall, Troy D.; Mountz, John D.; Hsu, Hui-Chen
J.I..
May 2015
Autoreactive B cells are associated with the development of several autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis. The low frequency of these cells represents a major barrier to their analysis. Ag tetramers prepared from linear epitopes represent a promising strategy for the identification of small subsets of Ag-reactive immune cells. This is challenging given the requirement for identification and validation of linear epitopes and the complexity of autoantibody responses, including the broad spectrum of autoantibody specificities and the contribution of isotype to pathogenicity. Therefore, we tested a two-tiered peptide microarray approach, coupled with epitope mapping of known autoantigens, to identify and characterize autoepitopes using the BXD2 autoimmune mouse model. Microarray results were verified through comparison with established age-associated profiles of autoantigen specificities and autoantibody class switching in BXD2 and control (C57BL/6) mice and high-throughput ELISA and ELISPOT analyses of synthetic peptides. Tetramers were prepared from two linear peptides derived from two RNA-binding proteins (RBPs): lupus La and 70-kDa U1 small nuclear ribonucleoprotein. Flow cytometric analysis of tetramer-reactive B cell subsets revealed a significantly higher frequency and greater numbers of RBP-reactive marginal zone precursor, transitional T3, and PDL-2+CD80+ memory B cells, with significantly elevated CD69 and CD86 observed in RBP+ marginal zone precursor B cells in the spleens of BXD2 mice compared with C57BL/6 mice, suggesting a regulatory defect. This study establishes a feasible strategy for the characterization of autoantigen-specific B cell subsets in different models of autoimmunity and, potentially, in humans.

Potent Adjuvanticity of a Pure TLR7-Agonistic Imidazoquinoline Dendrimer

Shukla, Nikunj M.; Salunke, Deepak B.; Balakrishna, Rajalakshmi; Mutz, Cole A.; Malladi, Subbalakshmi S.; David, Sunil A.
PLoS ONE.
Aug 2012
Engagement of toll-like receptors (TLRs) serve to link innate immune responses with adaptive immunity and can be exploited as powerful vaccine adjuvants for eliciting both primary and anamnestic immune responses. TLR7 agonists are highly immunostimulatory without inducing dominant proinflammatory cytokine responses. We synthesized a dendrimeric molecule bearing six units of a potent TLR7/TLR8 dual-agonistic imidazoquinoline to explore if multimerization of TLR7/8 would result in altered activity profiles. A complete loss of TLR8-stimulatory activity with selective retention of the TLR7-agonistic activity was observed in the dendrimer. This was reflected by a complete absence of TLR8-driven proinflammatory cytokine and interferon (IFN)-γ induction in human PBMCs, with preservation of TLR7-driven IFN-α induction. The dendrimer was found to be superior to the imidazoquinoline monomer in inducing high titers of high-affinity antibodies to bovine α-lactalbumin. Additionally, epitope mapping experiments showed that the dendrimer induced immunoreacti

Sensing Immune Responses with Customized Peptide Microarrays

Schirwitz, Christopher; Loeffler, Felix F.; Felgenhauer, Thomas; Stadler, Volker; Breitling, Frank; Bischoff, F. Ralf
Biointerphases.
Aug 2012
The intent to solve biological and biomedical questions in high-throughput led to an immense interest in microarray technologies. Nowadays, DNA microarrays are routinely used to screen for oligonucleotide interactions within a large variety of potential interaction partners. To study interactions on the protein level with the same efficiency, protein and peptide microarrays offer similar advantages, but their production is more demanding. A new technology to produce peptide microarrays with a laser printer provides access to affordable and highly complex peptide microarrays. Such a peptide microarray can contain up to 775 peptide spots per cm², whereby the position of each peptide spot and, thus, the amino acid sequence of the corresponding peptide, is exactly known. Compared to other techniques, such as the SPOT synthesis, more features per cm² at lower costs can be synthesized which paves the way for laser printed peptide microarrays to take on roles as efficient and affordable biomedical sensors. Here, we describe the laser printer-based synthesis of peptide microarrays and focus on an application involving the blood sera of tetanus immunized individuals, indicating the potential of peptide arrays to sense immune responses.

Physical Characterization of the “Immunosignaturing Effect”

Stafford, Phillip; Halperin, Rebecca; Legutki, Joseph Bart; Magee, Dewey Mitchell; Galgiani, John; Johnston, Stephen Albert
Mol Cell Proteomics.
Apr 2012
Identifying new, effective biomarkers for diseases is proving to be a challenging problem. We have proposed that antibodies may offer a solution to this problem. The physical features and abundance of antibodies make them ideal biomarkers. Additionally, antibodies are often elicited early in the ontogeny of different chronic and infectious diseases. We previously reported that antibodies from patients with infectious disease and separately those with Alzheimer’s disease display a characteristic and reproducible immunosignature on a microarray of 10,000 random sequence peptides. Here we investigate the physical and chemical parameters underlying how immunosignaturing works. We first show that a variety of monoclonal and polyclonal antibodies raised against different classes of antigens produce distinct profiles on this microarray and the relative affinities are determined. A proposal for how antibodies bind the random sequences is tested. Sera from vaccinated mice and people suffering from a fugal infection are individually assayed to determine the complexity of signals that can be distinguished. Based on these results, we propose that this simple, general and inexpensive system could be optimized to generate a new class of antibody biomarkers for a wide variety of diseases.

Single-Molecule Detection on a Protein-Array Assay Platform for the Exposure of a Tuberculosis Antigen

Schmidt, Ronny; Jacak, Jaroslaw; Schirwitz, Christopher; Stadler, Volker; Michel, Gerd; Marmé, Nicole; Schütz, Gerhard J.; Hoheisel, Jörg D.; Knemeyer, Jens-Peter
J. Proteome Res..
Jan 2011

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