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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

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.

A heterotypic assembly mechanism regulates CHIP E3 ligase activity

Das, Aniruddha; Thapa, Pankaj; Santiago, Ulises; Shanmugam, Nilesh; Banasiak, Katarzyna; Dąbrowska, Katarzyna; Nolte, Hendrik; Szulc, Natalia A; Gathungu, Rose M; Cysewski, Dominik; Krüger, Marcus; Dadlez, Michał; Nowotny, Marcin; Camacho, Carlos J; Hoppe, Thorsten; Pokrzywa, Wojciech
The EMBO Journal.
Aug 2022
CHIP (C‐terminus of Hsc70‐interacting protein) and its worm ortholog CHN‐1 are E3 ubiquitin ligases that link the chaperone system with the ubiquitin‐proteasome system (UPS). CHN‐1 can cooperate with UFD‐2, another E3 ligase, to accelerate ubiquitin chain formation; however, the basis for the high processivity of this E3s set has remained obscure. Here, we studied the molecular mechanism and function of the CHN‐1–UFD‐2 complex in Caenorhabditis elegans. Our data show that UFD‐2 binding promotes the cooperation between CHN‐1 and ubiquitin‐conjugating E2 enzymes by stabilizing the CHN‐1 U‐box dimer. However, HSP70/HSP‐1 chaperone outcompetes UFD‐2 for CHN‐1 binding, thereby promoting a shift to the autoinhibited CHN‐1 state by acting on a conserved residue in its U‐box domain. The interaction with UFD‐2 enables CHN‐1 to efficiently ubiquitylate and regulate S‐adenosylhomocysteinase (AHCY‐1), a key enzyme in the S‐adenosylmethionine (SAM) regeneration cycle, which is essential for SAM‐dependent methylation. Our results define the molecular mechanism underlying the synergistic cooperation of CHN‐1 and UFD‐2 in substrate ubiquitylation.

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.

Influenza‐associated thrombotic thrombocytopenic purpura: A report of two cases and a brief review of the literature

Onkarappa Mangala, Yashvin; Sweeney, Joseph D.
Vox Sanguinis.
Nov 2021
Background and Objectives Thrombotic thrombocytopenic purpura (TTP) is often preceded by a recent history of an acute infection and influenza is the most implicated virus. Materials and Methods We identified two cases of TTP, which were preceded by influenza between 2010 and 2021. In one patient, we epitope mapped the binding specificity of antibodies using an overlapping peptide approach of the stalk protein of Influenza B and the cysteine-rich spacer domain (CRSD) of ADAMTS13. A literature search was performed for reports of influenza-associated TTP over the period 1980–2021. Results Two patients were identified in which TTP was preceded by influenza, one Influenza A and the other Influenza B. Epitope mapping of the latter’s plasma identified target epitopes in both the stalk protein of Influenza B and CRSD of ADAMTS13. The literature review revealed only seven case reports, all but one from Europe or Asia and associated with Influenza A. Severe ADAMTS13 deficiency was demonstrated in only four cases. Conclusion We report the first small case series of influenza-associated TTP. Moreover, it is the first case implicating Influenza B and a mechanism favouring polyclonal B-cell proliferation rather than molecular mimicry as the stimulus to form anti-ADAMTS13 auto-antibodies is suggested.

The Potential Role of Human NME1 in Neuronal Differentiation of Porcine Mesenchymal Stem Cells: Application of NB-hNME1 as a Human NME1 Suppressor

Cho, Jin Hyoung; Ju, Won Seok; Seo, Sang Young; Kim, Bo Hyun; Kim, Ji-Su; Kim, Jong-Geol; Park, Soon Ju; Choo, Young-Kug
Int J Mol Sci.
Nov 2021
This study aimed to investigate the effects of the human macrophage (MP) secretome in cellular xenograft rejection. The role of human nucleoside diphosphate kinase A (hNME1), from the secretome of MPs involved in the neuronal differentiation of miniature pig adipose tissue-derived mesenchymal stem cells (mp AD-MSCs), was evaluated by proteomic analysis. Herein, we first demonstrate that hNME1 strongly binds to porcine ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 1 (pST8SIA1), which is a ganglioside GD3 synthase. When hNME1 binds with pST8SIA1, it induces degradation of pST8SIA1 in mp AD-MSCs, thereby inhibiting the expression of ganglioside GD3 followed by decreased neuronal differentiation of mp AD-MSCs. Therefore, we produced nanobodies (NBs) named NB-hNME1 that bind to hNME1 specifically, and the inhibitory effect of NB-hNME1 was evaluated for blocking the binding between hNME1 and pST8SIA1. Consequently, NB-hNME1 effectively blocked the binding of hNME1 to pST8SIA1, thereby recovering the expression of ganglioside GD3 and neuronal differentiation of mp AD-MSCs. Our findings suggest that mp AD-MSCs could be a potential candidate for use as an additive, such as an immunosuppressant, in stem cell transplantation.

The cellular modifier MOAG-4/SERF drives amyloid formation through charge complementation

Pras, Anita; Houben, Bert; Aprile, Francesco A.; Seinstra, Renée; Gallardo, Rodrigo; Janssen, Leen; Hogewerf, Wytse; Gallrein, Christian; De Vleeschouwer, Matthias; Mata-Cabana, Alejandro; Koopman, Mandy; Stroo, Esther; de Vries, Minke; Louise Edwards, Samantha; Kirstein, Janine; Vendruscolo, Michele; Falsone, Salvatore Fabio; Rousseau, Frederic; Schymkowitz, Joost; Nollen, Ellen A. A.
EMBO J.
Nov 2021
While aggregation-prone proteins are known to accelerate aging and cause age-related diseases, the cellular mechanisms that drive their cytotoxicity remain unresolved. The orthologous proteins MOAG-4, SERF1A, and SERF2 have recently been identified as cellular modifiers of such proteotoxicity. Using a peptide array screening approach on human amyloidogenic proteins, we found that SERF2 interacted with protein segments enriched in negatively charged and hydrophobic, aromatic amino acids. The absence of such segments, or the neutralization of the positive charge in SERF2, prevented these interactions and abolished the amyloid-promoting activity of SERF2. In protein aggregation models in the nematode worm Caenorhabditis elegans, protein aggregation and toxicity were suppressed by mutating the endogenous locus of MOAG-4 to neutralize charge. Our data indicate that MOAG-4 and SERF2 drive protein aggregation and toxicity by interactions with negatively charged segments in aggregation-prone proteins. Such charge interactions might accelerate primary nucleation of amyloid by initiating structural changes and by decreasing colloidal stability. Our study points at charge interactions between cellular modifiers and amyloidogenic proteins as potential targets for interventions to reduce age-related protein toxicity.

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