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

Peptide microarray analysis of in-silico predicted B-cell epitopes in SARS-CoV-2 sero-positive healthcare workers in Bulawayo, Zimbabwe

Vengesai, Arthur; Naicker, Thajasvarie; Midzi, Herald; Kasambala, Maritha; Muleya, Victor; Chipako, Isaac; Choto, Emilia; Moyo, Praise; Mduluza, Takafira
Acta Tropica.
Nov 2022

Vivaxin genes encode highly immunogenic, non-variant antigens on the Trypanosoma vivax cell-surface

Romero-Ramirez, Alessandra; Casas-Sánchez, Aitor; Autheman, Delphine; Duffy, Craig W.; Brandt, Cordelia; Clare, Simon; Harcourt, Katherine; André, Marcos Rogério; de Almeida Castilho Neto, Kayo José Garcia; Teixeira, Marta M. G.; Machado, Rosangela Zacharias; Coombes, Janine; Flynn, Robin J.; Wright, Gavin J.; Jackson, Andrew P.
PLoS Negl Trop Dis.
Sep 2022
Trypanosoma vivax is a unicellular hemoparasite, and a principal cause of animal African trypanosomiasis (AAT), a vector-borne and potentially fatal livestock disease across sub-Saharan Africa. Previously, we identified diverse T. vivax-specific genes that were predicted to encode cell surface proteins. Here, we examine the immune responses of naturally and experimentally infected hosts to these unique parasite antigens, to identify immunogens that could become vaccine candidates. Immunoprofiling of host serum shows that one particular family (Fam34) elicits a consistent IgG antibody response. This gene family, which we now call Vivaxin, encodes at least 124 transmembrane glycoproteins that display quite distinct expression profiles and patterns of genetic variation. We focused on one gene (viv-β8) that encodes one particularly immunogenic vivaxin protein and which is highly expressed during infections but displays minimal polymorphism across the parasite population. Vaccination of mice with VIVβ8 adjuvanted with Quil-A elicits a strong, balanced immune response and delays parasite proliferation in some animals but, ultimately, it does not prevent disease. Although VIVβ8 is localized across the cell body and flagellar membrane, live immunostaining indicates that VIVβ8 is largely inaccessible to antibody in vivo. However, our phylogenetic analysis shows that vivaxin includes other antigens shown recently to induce immunity against T. vivax. Thus, the introduction of vivaxin represents an important advance in our understanding of the T. vivax cell surface. Besides being a source of proven and promising vaccine antigens, the gene family is clearly an important component of the parasite glycocalyx, with potential to influence host-parasite interactions.

Anti-neuronal antibodies against brainstem antigens are associated with COVID-19

Lucchese, Guglielmo; Vogelgesang, Antje; Boesl, Fabian; Raafat, Dina; Holtfreter, Silva; Bröker, Barbara M.; Stufano, Angela; Fleischmann, Robert; Prüss, Harald; Franke, Christiana; Flöel, Agnes
eBioMedicine.
Sep 2022
Background Understanding how SARS-CoV-2 affects respiratory centres in the brainstem may help to preclude assisted ventilation for patients in intensive care setting. Viral invasion appears unlikely, although autoimmunity has been implicated, the responsible antigens remain unknown. We previously predicted the involvement of three epitopes within distinct brainstem proteins: disabled homolog 1 (DAB1), apoptosis-inducing-factor-1 (AIFM1), and surfeit-locus-protein-1 (SURF1). Methods Here, we used microarrays to screen serum from COVID-19 patients admitted to intensive care and compared those with controls who experienced mild course of the disease. Findings The results confirm the occurrence of IgG and IgM antibodies against the hypothesised epitopes in COVID-19 patients. Importantly, while IgM levels were similar in both groups, IgG levels were significantly elevated in severely ill patients compared to controls, suggesting a pathogenic role of IgG. Interpretation The newly discovered anti-neuronal antibodies might be promising markers of severe disease and the targeted peptide epitopes might be used for targeted immunomodulation. Further work is needed to determine whether these antibodies may play a role in long-COVID.

Identification of Equine Arteritis Virus Immunodominant Epitopes Using a Peptide Microarray

Mayers, Jo; Westcott, David; Steinbach, Falko
Viruses.
Aug 2022
Using the commercially available PEPperCHIP® microarray platform, a peptide microarray was developed to identify immunodominant epitopes for the detection of antibodies against Equine arteritis virus (EAV). For this purpose, the whole EAV Bucyrus sequence was used to design a total of 1250 peptides that were synthesized and spotted onto a microarray slide. A panel of 28 serum samples representing a selection of EAV strains was tested using the microarray. Of the 1250 peptides, 97 peptides (7.76%) showed reactivity with the EAV-positive samples. No single peptide was detected by all the positive serum samples. Seven peptides repeatedly showed reactivity above the cut-off and were considered to have diagnostic potential. Five of these peptides were within the immunodominant GP5 protein and two were within the replicase polyprotein regions NSP2 and NSP10, located in ORF1. The diagnostic sensitivity of the seven peptides selected was low, ranging from 5% to 55%; however, the combined diagnostic sensitivity and specificity of the seven peptides was 90% and 100%, respectively. This data demonstrate that multiple peptide sequences would be required to design a comprehensive serological test to cover the diversity of the EAV strains and the individual immune responses of horses.

Targeting FLT3 by new-generation antibody-drug-conjugate in combination with kinase inhibitors for treatment of AML

Roas, Maike; Vick, Binje; Kasper, Marc-André; Able, Marina; Polzer, Harald; Gerlach, Marcus; Kremmer, Elisabeth; Hecker, Judith S.; Schmitt, Saskia; Stengl, Andreas; Waller, Verena; Hohmann, Natascha; Festini, Moreno; Ludwig, Alexander Edmund; Rohrbacher, Lisa; Herold, Tobias; Subklewe, Marion; Götze, Katharina S.; Hackenberger, Christian P.R.; Schumacher, Dominik; Helma-Smets, Jonas; Jeremias, Irmela; Leonhardt, Heinrich; Spiekermann, Karsten
Fms like tyrosine kinase 3 (FLT3) is often overexpressed or constitutively activated by internal tandem duplication (ITD) and tyrosine kinase domain (TKD) mutations in acute myeloid leukemia (AML). Despite the use of receptor tyrosine kinase inhibitors (TKI) in FLT3-ITD positive AML, the prognosis of patients is still poor and further improvement of therapy is required. Targeting FLT3 independent of mutations by antibody‑drug‑conjugates (ADCs) is a promising strategy for AML therapy. Here, we report the development and preclinical characterization of a novel FLT3‑targeting ADC, 20D9-ADC, which was generated by applying the innovative P5 conjugation technology. In vitro, 20D9‑ADC mediated potent cytotoxicity to Ba/F3 cells expressing transgenic FLT3 or FLT3-ITD, to AML cell lines and to FLT3-ITD positive patient derived xenograft AML cells. In vivo, 20D9‑ADC treatment led to a significant tumor reduction and even durable complete remission in AML xenograft models. Further, 20D9‑ADC demonstrated no severe hematotoxicity in in vitro colony formation assays using concentrations that were cytotoxic in AML cell line treatment. The combination of 20D9-ADC with the TKI midostaurin showed strong synergy in vitro and in vivo, leading to reduction of aggressive AML cells below the detection limit. Our data indicate that targeting FLT3 with an advanced new-generation ADC is a promising and potent antileukemic strategy, especially when combined with FLT3-TKI in FLT3‑ITD positive AML.

The Correlation between Subolesin-Reactive Epitopes and Vaccine Efficacy

Contreras, Marinela; Kasaija, Paul D.; Kabi, Fredrick; Mugerwa, Swidiq; De la Fuente, José
Vaccines.
Aug 2022
Vaccination is an environmentally-friendly alternative for tick control. The tick antigen Subolesin (SUB) has shown protection in vaccines for the control of multiple tick species in cattle. Additionally, recent approaches in quantum vaccinomics have predicted SUB-protective epitopes and the peptide sequences involved in protein–protein interactions in this tick antigen. Therefore, the identification of B-cell–reactive epitopes by epitope mapping using a SUB peptide array could be essential as a novel strategy for vaccine development. Subolesin can be used as a model to evaluate the effectiveness of these approaches for the identification of protective epitopes related to vaccine protection and efficacy. In this study, the mapping of B-cell linear epitopes of SUB from three different tick species common in Uganda (Rhipicephalus appendiculatus, R. decoloratus, and Amblyomma variegatum) was conducted using serum samples from two cattle breeds immunized with SUB-based vaccines. The results showed that in cattle immunized with SUB from R. appendiculatus (SUBra) all the reactive peptides (Z-score > 2) recognized by IgG were also significant (Z-ratio > 1.96) when compared to the control group. Additionally, some of the reactive peptides recognized by IgG from the control group were also recognized in SUB cocktail–immunized groups. As a significant result, cattle groups that showed the highest vaccine efficacy were Bos indicus immunized with a SUB cocktail (92%), and crossbred cattle were immunized with SUBra (90%) against R. appendiculatus ticks; the IgG from these groups recognized overlapping epitopes from the peptide SPTGLSPGLSPVRDQPLFTFRQVGLICERMMKERESQIRDEYDHVLSAKLAEQYDTFVKFTYDQKRFEGATPSYLS (Z-ratio > 1.96), which partially corresponded to a Q38 peptide and the SUB protein interaction domain. These identified epitopes could be related to the protection and efficacy of the SUB-based vaccines, and new chimeras containing these protective epitopes could be designed using this new approach.

Development of broadly neutralizing antibodies targeting the cytomegalovirus subdominant antigen gH

Parsons, Andrea J.; Ophir, Sabrina I.; Duty, J. Andrew; Kraus, Thomas A.; Stein, Kathryn R.; Moran, Thomas M.; Tortorella, Domenico
Commun Biol.
Apr 2022
Human cytomegalovirus (HCMV) is a β-herpesvirus that increases morbidity and mortality in immunocompromised individuals including transplant recipients and newborns. New anti-HCMV therapies are an urgent medical need for diverse patient populations. HCMV infection of a broad range of host tissues is dependent on the gH/gL/gO trimer and gH/gL/UL28/UL130/UL131A pentamer complexes on the viral envelope. We sought to develop safe and effective therapeutics against HCMV by generating broadly-neutralizing, human monoclonal antibodies (mAbs) from VelocImmune® mice immunized with gH/gL cDNA. Following high-throughput binding and neutralization screening assays, 11 neutralizing antibodies were identified with unique CDR3 regions and a high-affinity (KD 1.4-65 nM) to the pentamer complex. The antibodies bound to distinct regions within Domains 1 and 2 of gH and effectively neutralized diverse clinical strains in physiologically relevant cell types including epithelial cells, trophoblasts, and monocytes. Importantly, combined adminstration of mAbs with ganciclovir, an FDA approved antiviral, greatly limited virus dissemination. Our work identifies several anti-gH/gL mAbs and sheds light on gH neutralizing epitopes that can guide future vaccine strategies.

Construction of a Large Size Human Immunoglobulin Heavy Chain Variable (VH) Domain Library, Isolation and Characterization of Novel Human Antibody VH Domains Targeting PD-L1 and CD22

Sun, Zehua; Li, Wei; Mellors, John W.; Orentas, Rimas; Dimitrov, Dimiter S.
Front Immunol.
Apr 2022
10.3389/fimmu.2022.869825
Phage display is a well-established technology for in vitro selection of monoclonal antibodies (mAb), and more than 12 antibodies isolated from phage displayed libraries of different formats have been approved for therapy. We have constructed a large size (10^11) human antibody VH domain library based on thermo-stable, aggregation-resistant scaffolds. This diversity was obtained by grafting naturally occurring CDR2s and CDR3s from healthy donors with optimized primers into the VH library. This phage-displayed library was used for bio-panning against various antigens. So far, panels of binders have been isolated against different viral and tumor targets, including the SARS-CoV-2 RBD, HIV-1 ENV protein, mesothelin and FLT3. In the present study, we discuss domain library construction, characterize novel VH binders against human CD22 and PD-L1, and define our design process for antibody domain drug conjugation (DDC) as tumoricidal reagents. Our study provides examples for the potential applications of antibody domains derived from library screens in therapeutics and provides key information for large size human antibody domain library construction.

Inhibition of lung microbiota-derived proapoptotic peptides ameliorates acute exacerbation of pulmonary fibrosis

D’Alessandro-Gabazza, Corina N.; Yasuma, Taro; Kobayashi, Tetsu; Toda, Masaaki; Abdel-Hamid, Ahmed M.; Fujimoto, Hajime; Hataji, Osamu; Nakahara, Hiroki; Takeshita, Atsuro; Nishihama, Kota; Okano, Tomohito; Saiki, Haruko; Okano, Yuko; Tomaru, Atsushi; Fridman D’Alessandro, Valeria; Shiraishi, Miyako; Mizoguchi, Akira; Ono, Ryoichi; Ohtsuka, Junpei; Fukumura, Masayuki; Nosaka, Tetsuya; Mi, Xuenan; Shukla, Diwakar; Kataoka, Kensuke; Kondoh, Yasuhiro; Hirose, Masaki; Arai, Toru; Inoue, Yoshikazu; Yano, Yutaka; Mackie, Roderick I.; Cann, Isaac; Gabazza, Esteban C.
Nat Commun.
Mar 2022
Idiopathic pulmonary fibrosis is an incurable disease of unknown etiology. Acute exacerbation of idiopathic pulmonary fibrosis is associated with high mortality. Excessive apoptosis of lung epithelial cells occurs in pulmonary fibrosis acute exacerbation. We recently identified corisin, a proapoptotic peptide that triggers acute exacerbation of pulmonary fibrosis. Here, we provide insights into the mechanism underlying the processing and release of corisin. Furthermore, we demonstrate that an anticorisin monoclonal antibody ameliorates lung fibrosis by significantly inhibiting acute exacerbation in the human transforming growth factorβ1 model and acute lung injury in the bleomycin model. By investigating the impact of the anticorisin monoclonal antibody in a general model of acute lung injury, we further unravel the potential of corisin to impact such diseases. These results underscore the role of corisin in the pathogenesis of acute exacerbation of pulmonary fibrosis and acute lung injury and provide a novel approach to treating this incurable disease.

In vitro evolution of myc-tag antibodies: in-depth specificity and affinity analysis of Myc1-9E10 and Hyper-Myc

Russo, Giulio; Unkauf, Tobias; Meier, Doris; Wenzel, Esther Veronika; Langreder, Nora; Schneider, Kai-Thomas; Wiesner, Rebecca; Bischoff, Ralf; Stadler, Volker; Dübel, Stefan
One of the most widely used epitope tags is the myc-tag, recognized by the anti-c-Myc hybridoma antibody Myc1-9E10. Combining error-prone PCR, DNA shuffling and phage display, we generated an anti-c-Myc antibody variant (Hyper-Myc) with monovalent affinity improved to 18 nM and thermal stability increased by 37%. Quantification of capillary immunoblots and by flow cytometry demonstrated improved antigen detection by Hyper-Myc. Further, three different species variants of this antibody were generated to allow the use of either anti-human, anti-mouse or anti-rabbit Fc secondary antibodies for detection. We characterized the specificity of both antibodies in depth: individual amino acid exchange mapping demonstrated that the recognized epitope was not changed by the in vitro evolution process. A laser printed array of 29,127 different epitopes representing all human linear B-cell epitopes of the Immune Epitope Database allowing to chart unwanted reactivities with mimotopes showed these to be very low for both antibodies and not increased for Hyper-Myc despite its improved affinity. The very low background reactivity of Hyper-Myc was confirmed by staining of myc-tag transgenic zebrafish whole mounts. Hyper-Myc retains the very high specificity of Myc1-9E10 while allowing myc-tag detection at lower concentrations and with either anti-mouse, anti-rabbit or anti human secondary antibodies.

Increased neutralization and IgG epitope identification after MVA-MERS-S booster vaccination against Middle East respiratory syndrome

Fathi, Anahita; Dahlke, Christine; Krähling, Verena; Kupke, Alexandra; Okba, Nisreen M. A.; Raadsen, Matthijs P.; Heidepriem, Jasmin; Müller, Marcel A.; Paris, Grigori; Lassen, Susan; Klüver, Michael; Volz, Asisa; Koch, Till; Ly, My L.; Friedrich, Monika; Fux, Robert; Tscherne, Alina; Kalodimou, Georgia; Schmiedel, Stefan; Corman, Victor M.; Hesterkamp, Thomas; Drosten, Christian; Loeffler, Felix F.; Haagmans, Bart L.; Sutter, Gerd; Becker, Stephan; Addo, Marylyn M.
Vaccine development is essential for pandemic preparedness. We previously conducted a Phase 1 clinical trial of the vector vaccine candidate MVA-MERS-S against the Middle East respiratory syndrome coronavirus (MERS-CoV), expressing its full spike glycoprotein (MERS-CoV-S), as a homologous two-dose regimen (Days 0 and 28). Here, we evaluate a third vaccination with MVA-MERS-S in a subgroup of trial participants one year after primary immunization. A booster vaccination with MVA-MERS-S is safe and well-tolerated. Both binding and neutralizing anti-MERS-CoV antibody titers increase substantially in all participants and exceed maximum titers observed after primary immunization more than 10-fold. We identify four immunogenic IgG epitopes, located in the receptor-binding domain (RBD, n=1) and the S2 subunit (n=3) of MERS-CoV-S. The level of baseline anti-human coronavirus antibody titers does not impact the generation of anti-MERS-CoV antibody responses. Our data support the rationale of a booster vaccination with MVA-MERS-S and encourage further investigation in larger trials.

Analysis of the Immune Response and Identification of Antibody Epitopes Against the Sigma C Protein of Avian Orthoreovirus Following Immunization with Live or Inactivated Vaccines

Dawe, W. H.; Kapczynski, D. R.; Linnemann, E. G.; Gauthiersloan, V. R.; Sellers, H. S.
Avian Diseases.
Jan 2022

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