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

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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
10.1016/j.ab.2019.03.004
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.

Anti-Trail Antibodies and Methods of Use

Boico, Olga; Tzaban, Salit; Oved, Kfir; Cohen-Dotan, Assaf; Eden, Eran
May 2019
An antibody comprising an antigen recognition domain that binds specifically the extracellular domain of TNF-related apoptosis-inducing ligand (TRAIL) between amino acids 95-155 and/or amino acids 190-210 is disclosed. Uses thereof are also disclosed.

High-density Peptide Arrays Help to Identify Linear Immunogenic B-cell Epitopes in Individuals Naturally Exposed to Malaria Infection

Jaenisch, Thomas; Heiss, Kirsten; Fischer, Nico; Geiger, Carolin; Bischoff, F. Ralf; Moldenhauer, Gerhard; Rychlewski, Leszek; Sié, Ali; Coulibaly, Boubacar; Seeberger, Peter H.; Wyrwicz, Lucjan S.; Breitling, Frank; Loeffler, Felix F.
Mol Cell Proteomics.
Apr 2019
10.1074/mcp.RA118.000992
High-density peptide arrays are an excellent means to profile anti-plasmodial antibody responses. Different protein intrinsic epitopes can be distinguished, and additional insights are gained, when compared with assays involving the full-length protein. Distinct reactivities to specific epitopes within one protein may explain differences in published results, regarding immunity or susceptibility to malaria. We pursued three approaches to find specific epitopes within important plasmodial proteins, (1) twelve leading vaccine candidates were mapped as overlapping 15-mer peptides, (2) a bioinformatical approach served to predict immunogenic malaria epitopes which were subsequently validated in the assay, and (3) randomly selected peptides from the malaria proteome were screened as a control. Several peptide array replicas were prepared, employing particle-based laser printing, and were used to screen 27 serum samples from a malaria-endemic area in Burkina Faso, West Africa. The immunological status of the individuals was classified as “protected” or “unprotected” based on clinical symptoms, parasite density, and age. The vaccine candidate screening approach resulted in significant hits in all twelve proteins and allowed us (1) to verify many known immunogenic structures, (2) to map B-cell epitopes across the entire sequence of each antigen and (3) to uncover novel immunogenic epitopes. Predicting immunogenic regions in the proteome of the human malaria parasite Plasmodium falciparum, via the bioinformatics approach and subsequent array screening, confirmed known immunogenic sequences, such as in the leading malaria vaccine candidate CSP and discovered immunogenic epitopes derived from hypothetical or unknown proteins.

Automated laser-assisted synthesis of microarrays for infectious disease research

Paris, Grigori; Heidepriem, Jasmin; Tsouka, Alexandra; Mende, Marco; Eickelmann, Stephan; Loeffler, Felix F.
Mar 2019
10.1117/12.2516781
We developed a next-generation method for chemical in–situ combinatorial biomolecule array synthesis. This allows for an unprecedented combinatorial freedom in the automated chemical synthesis of molecule arrays with very high spot densities. Key feature of this new method is an automated positioning and laser transfer process: Small solid material spots are rapidly transferred from a donor film to an acceptor surface, requiring only minute amounts of materials. The transfer is performed with different and easy-to-produce donor slides. Each donor slide bears a thin polymer film, embedding one type of monomer. The coupling reaction occurs in a separate heating step, where the matrix becomes viscous and building blocks can diffuse within the material and couple to the acceptor surface. Since these transferred material spots are only several nanometers thin, this method allows for a consecutive multi-layer material deposition of e.g. activation reagents and amino acids. Subsequent heat-induced mixing facilitates an in–situ activation and coupling of the monomers. Positioning several of such resin spots, containing different chemical reagents, on top of each other, will enable for the first time in such small dimensions unique chemical synthesis strategies for each spot. Amount and concentration of the deposited materials can be adjusted with the laser parameters. Employing similar arrays, we can analyze the human immune response towards the proteome of different pathogens. We screened several peptide array replicas with different patient sera. The screenings resulted in significant hits in several proteins with interesting implications for future diagnostics and vaccine development.

Methods of Selecting Binding Reagents

Mallick, Parag; Egertson, Jarrett
Feb 2019
Methods and systems are provided herein for selecting an affinity reagent which binds a desired peptide epitope in a plurality of sequence contexts. The method relies on obtaining a peptide library, each peptide having the sequence αΧβ, wherein X is the desired peptide epitope, wherein each of a and β comprise an amino acid, using the peptide library to select an affinity reagent.

Patent infections with soil-transmitted helminths and Schistosoma mansoni are not associated with increased prevalence of antibodies to the Onchocerca volvulus peptide epitopes OvMP-1 and OvMP-23

Vlaminck, Johnny; Lagatie, Ole; Verheyen, Ann; Dana, Daniel; Van Dorst, Bieke; Mekonnen, Zeleke; Levecke, Bruno; Stuyver, Lieven J.
Parasites Vectors.
Jan 2019
10.1186/s13071-019-3308-z
Background Ov16 serology is considered a reference method for Onchocerca volvulus epidemiological mapping. Given the suboptimal sensitivity of this test and the fact that seroconversion takes more than a year after infection, additional serological tests might be needed to guide onchocerciasis elimination programmes. Recently, two linear epitopes encoded in OvMP-1 and OvMP-23 peptides were introduced as serological markers, but the observed antibody cross-reactivity in samples originating from Onchocerca volvulus non-endemic areas required further investigation. Methods We evaluated both peptide markers in an O. volvulus hypo-endemic setting in Jimma Town, Ethiopia using peptide ELISA. For all individuals (n = 303), the infection status with soil-transmitted helminths and Schistosoma mansoni was known. Results We found that 11 (3.6%) individuals were positive for anti-Ov16 IgG4 antibodies, while 34 (11.2%) and 15 (5.0%) individuals were positive for OvMP-1 and OvMP-23, respectively. Out of the 34 OvMP-1 positive samples, 33 were negative on the Ov16 IgG4 ELISA. Similarly, out of the 15 OvMP-23 positive samples, 14 scored negative on this reference method. No difference in seroprevalence for all three markers could be observed between uninfected individuals and individuals infected with different soil-transmitted helminths or S. mansoni. Moreover, the intensity of the response to OvMP-1, OvMP-23 or Ov16 was not significantly stronger in individuals carrying patent STH or S. mansoni infections, nor was there any correlation between the intensities of the responses to the three different antigens. Conclusions This study demonstrates that a patent infection with either soil-transmitted helminths or S. mansoni does not lead to increased antibody recognition of both OvMP-1 and OvMP23.

An oligoclonal combination of human monoclonal antibodies able to neutralize tetanus toxin in vivo

Aliprandini, Eduardo; Takata, Daniela Yumi; Lepique, Ana; Kalil, Jorge; Boscardin, Silvia Beatriz; Moro, Ana Maria
Toxicon: X.
Jan 2019
10.1016/j.toxcx.2019.100006
The use of antibody-based therapy to treat a variety of diseases and conditions is well documented. The use of antibodies as an antidote to treat tetanus infections was one of the first examples of immunotherapy and remains the standard of care for cases involving potential infections. Plasma-derived immunoglobulins obtained from human or horse pose risks of infection from undetectable emergent viruses or may cause anaphylaxis. Further, there is a lack of consistency between lots. In the search for new formulations, we obtained a series of clonally related human monoclonal antibodies (mAbs) derived from B cells sorted from donors that presented anti-tetanus neutralizing titers. Donors were revaccinated prior to blood collection. Different strategies were used for single-cell sorting, since it was challenging to identify cells at a very low frequency: memory B cell sorting using fluorescent-labeled tetanus toxoid and toxin as baits, and plasmablast sorting done shortly after revaccination. Screening of the recombinant mAbs with the whole tetanus toxin allowed us to select candidates with therapeutic potential, since mAbs to different domains can contribute additively to the neutralizing effect. Because of selective binding to different domains, we tested mAbs individually, or in mixtures of two or three, in the neutralizing in vivo assay specified by Pharmacopeia for the determination of polyclonal hyperimmune sera potency. An oligoclonal mixture of three human mAbs completely neutralized the toxin injected in the animals, signaling an important step for clinical mAb development.

Novel targets of acinetobacter baumannii

Urwyler, Simon; Haake, Markus; Rudolf, Michael
Jan 2019
The present invention provides antigenic polypeptides expressed during an infection by a pathogenic organism, such as Acinetobacter and compositions comprising these polypeptides. The invention further provides compositions for use in treating, preventing or detecting a bacterial infection, in particular vaccine compositions using the antigenic polypeptides. The invention further provides antibodies directed to said antigenic polypeptides.

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
10.1038/s41598-017-17071-0
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.

A novel neutralizing human monoclonal antibody broadly abrogates hepatitis C virus infection in vitro and in vivo

Desombere, Isabelle; Mesalam, Ahmed Atef; Urbanowicz, Richard A.; Van Houtte, Freya; Verhoye, Lieven; Keck, Zhen-Yong; Farhoudi, Ali; Vercauteren, Koen; Weening, Karin E.; Baumert, Thomas F.; Patel, Arvind H.; Foung, Steven K.H.; Ball, Jonathan; Leroux-Roels, Geert; Meuleman, Philip
Antiviral Research.
Dec 2017
10.1016/j.antiviral.2017.10.015
Infections with hepatitis C virus (HCV) represent a worldwide health burden and a prophylactic vaccine is still not available. Liver transplantation (LT) is often the only option for patients with HCV-induced end-stage liver disease. However, immediately after transplantation, the liver graft becomes infected by circulating virus, resulting in accelerated progression of liver disease. Although the efficacy of HCV treatment using direct-acting antivirals has improved significantly, immune compromised LT-patients and patients with advanced liver disease remain difficult to treat. As an alternative approach, interfering with viral entry could prevent infection of the donor liver. We generated a human monoclonal antibody (mAb), designated 2A5, which targets the HCV envelope. The neutralizing activity of mAb 2A5 was assessed using multiple prototype and patient-derived HCV pseudoparticles (HCVpp), cell culture produced HCV (HCVcc), and a human-liver chimeric mouse model. Neutralization levels observed for mAb 2A5 were generally high and mostly superior to those obtained with AP33, a well-characterized HCV-neutralizing monoclonal antibody. Using humanized mice, complete protection was observed after genotype 1a and 4a HCV challenge, while only partial protection was achieved using gt1b and 6a isolates. Epitope mapping revealed that mAb 2A5 binding is conformation-dependent and identified the E2-region spanning amino acids 434 to 446 (epitope II) as the predominant contact domain. Conclusion: mAb 2A5 shows potent anti-HCV neutralizing activity both in vitro and in vivo and could hence represent a valuable candidate to prevent HCV recurrence in LT-patients. In addition, the detailed identification of the neutralizing epitope can be applied for the design of prophylactic HCV vaccines.

A recombinant BBSome core complex and how it interacts with ciliary cargo

Klink, Björn Udo; Zent, Eldar; Juneja, Puneet; Kuhlee, Anne; Raunser, Stefan; Wittinghofer, Alfred
Nov 2017
10.7554/eLife.27434
Cilia are small, antenna-like structures on the surface of eukaryotic cells that harbor a unique set of sensory proteins, including GPCRs and other membrane proteins. The transport of these proteins involves the BBSome, an eight-membered protein complex that is recruited to ciliary membranes by the G-protein Arl6. BBSome malfunction leads to Bardet-Biedl syndrome, a ciliopathy with severe consequences. Short ciliary targeting sequences (CTS) have been identified that trigger the transport of ciliary proteins. However, mechanistic studies that relate ciliary targeting to BBSome binding are missing. Here we used heterologously expressed BBSome subcomplexes to analyze the complex architecture and to investigate the binding of GPCRs and other receptors to the BBSome. A stable heterohexameric complex was identified that binds to GPCRs with interactions that only partially overlap with previously described CTS, indicating a more complex recognition than anticipated. Arl6•GTP does not affect these interactions, suggesting no direct involvement in cargo loading/unloading.

Efficacy of an Adenoviral Vectored Multivalent Centralized Influenza Vaccine

Lingel, Amy; Bullard, Brianna L.; Weaver, Eric A.
Sci Rep.
Nov 2017
10.1038/s41598-017-14891-y
Mice were immunized with Adenovirus expressing the H1-con, H2-con, H3-con and H5-con HA consensus genes in combination (multivalent) and compared to mice immunized with the traditional 2010–2011 FluZone and FluMist seasonal vaccines. Immunized mice were challenged with 10–100 MLD50 of H1N1, H3N1, H3N2 and H5N1 influenza viruses. The traditional vaccines induced robust levels of HA inhibition (HI) titers, but failed to protect against five different heterologous lethal influenza challenges. Conversely, the multivalent consensus vaccine (1 × 1010 virus particles (vp)/mouse) induced protective HI titers of ≥40 against 8 of 10 influenza viruses that represent a wide degree of divergence within the HA subtypes and protected 100% of mice from 8 of 9 lethal heterologous influenza virus challenges. The vaccine protection was dose dependent, in general, and a dose as low as 5 × 107 vp/mouse still provided 100% survival against 7 of 9 lethal heterologous influenza challenges. These data indicate that very low doses of Adenovirus-vectored consensus vaccines induce superior levels of immunity against a wide divergence of influenza subtypes as compared to traditional vaccines. These doses are scalable and translatable to humans and may provide the foundation for complete and long-lasting anti-influenza immunity.

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