Contact
Quote

Home » Publications

Publications

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

Filter by
Filtered (34)
Filters
Show (34)
Cancel
Showing most recent

Systematic analysis of the RGS2 degron reveals characteristics of substrate recognition by the F-box protein FBXO44

McNabb, Harrison J.; Cho, Eugene; Pitman, Mary; Rushton, Phillip S.; Mobley, David; Sjögren, Benita
Journal of Biological Chemistry.
Nov 2025
10.1016/j.jbc.2025.110757
Regulator of G protein signaling 2 (RGS2) negatively modulates signaling downstream of G protein–coupled receptors by accelerating GTP hydrolysis at Gα subunits of heterotrimeric G proteins. Decreased RGS2 levels are implicated in numerous diseases, including cardiovascular disease and asthma. Thus, identifying selective means of enhancing RGS2 protein levels would be a viable therapeutic strategy. RGS2 is rapidly degraded through the ubiquitin–proteasomal pathway, and we previously identified F-box only protein 44 (FBXO44) as the substrate recognition component of the E3 ligase responsible for facilitating RGS2 degradation. As such, the RGS2–FBXO44 interaction is a potential target for pharmacological intervention. Detailed information on the FBXO44 recognition site (degron) in RGS2 will aid in structure-based small-molecule inhibitor design, as well as in identifying additional FBXO44 targets, which would help predict possible side effects of targeting this interaction. Thus, the goal of this study was to dissect the molecular properties for FBXO44 binding of the RGS2 degron. We used a peptide array utilizing systematic residue substitution, combined with AlphaFold modeling and molecular dynamics simulations, to identify several amino acid changes that altered binding both positively and negatively. Finally, we experimentally confirmed our results in cells through coimmunoprecipitation and proteasomal inhibition, using full-length RGS2. Altogether, these results provide structural insights into RGS2–FBXO44 binding, which will aid in structure-guided drug discovery efforts. It also provides a framework for building a consensus recognition motif for FBXO44, which could aid in identifying more substrates for this understudied F-box protein.

Anti-TRPV2 Autoantibody Linked to Sudden Infant Death Syndrome

Maguy, Ange; Tessier, Agnès; Mahendran, Yuvaraj; Denis, Manon; Lauzier, Benjamin; Charpentier, Flavien; Li, Jin
Jul 2025
10.1161/circulationaha.125.073748
As a leading cause of infant death, sudden infant death syndrome (SIDS) remains a perplexing diagnosis with no clear underlying biological substrate.1 In the past decade, studies have emerged demonstrating that circulating autoantibodies targeting cardiac antigens can underlie life-threatening arrhythmias.2 Because autoimmunity as a cause of SIDS has not yet been explored, we screened infant serum samples for the presence of autoantibodies targeting cardiac ion channels and examined how immunoglobulins may play a driving role in the pathogenesis of SIDS. Comparing cases of SIDS and accidental suffocation and strangulation in bed with healthy controls, we established the autoantibody profile of 47 serum samples using peptide microarray (Figure [A]), as previously described.2 Strikingly, only 1 single autoantibody targeting the transient receptor potential vanilloid 2 (TRPV2) channel (PTGPNATESVQPMEGQEDEG) was significantly associated with SIDS (P=0.028 versus controls, the default correction in limma). Collectively, we detected anti-TRPV2 autoantibodies in 84.6% of infants with SIDS compared with 50.0% in cases of accidental suffocation and strangulation in bed and 25.0% in controls.

Mapping autoantibody targets of full-length C-reactive protein in systemic lupus erythematosus: importance for neutrophil function and classical complement activation

Karlsson, Jesper; Wirestam, Lina; Duàn, Hanna; Ahmad, Suhana; Appelgren, Daniel; Enocsson, Helena; Wetterö, Jonas; Sjöwall, Christopher
Front. Immunol..
May 2025
10.3389/fimmu.2025.1578372
C-reactive protein (CRP) is an important pattern recognition molecule of innate immunity. Autoantibodies targeting CRP are common in patients with systemic lupus erythematosus (SLE) and the levels correlate with disease activity. The purpose of this study was to investigate binding sites of IgG autoantibodies on the full linear sequence of CRP and identify potential associations with clinical variables in well-characterized SLE patients; a secondary aim was to investigate the effect of an epitope-based synthesized peptide motif on neutrophil functions. The levels of anti-CRP and SLE-associated antibodies were assessed, and a microarray-based linear epitope mapping was performed to detect binding sites on the full CRP monomer. We observed that anti-CRP antibodies bind to a variety of linear epitopes with a higher prevalence in SLE compared to healthy blood donors. Eleven unique epitopes were identified, of which five were found exclusively in SLE. Furthermore, we show that patients with anticardiolipin IgG and/or anti-β2GPI IgG antibodies have a higher number of positive CRP epitopes, and some CRP autoantibody-specificities associate with antiphospholipid antibodies, disease activity, and classical complement activation. In addition, one identified motif was selected, synthesized, and used for studying neutrophil function. This peptide showed modulatory capacity on neutrophil oxidative burst and chemotaxis, but not on neutrophil extracellular trap formation. Our results implicate a wide variation of anti-CRP autoantibody binding motifs of the linear structure of CRP in SLE patients. Some epitopes have the potential to modify innate host responses of relevance to the pathogenesis of SLE.

Preclinical characterization of an active immunotherapy targeting calcitonin gene-related peptide

Boyd, Justin D.; Wang, Shixia; Lin, Hsiao-Wen; Hsieh, Yueh-Ting; Sun, Yu Shuang; Thibodeaux, Brett A.; Lu, Hanxin; Sahni, Jaya; Wiggins, Jonathan; Longo, Matthew S.; Brooks, Jeanne K.; Vroom, Madeline M.; Chang, Yi-Pin; Liu, Zhi; Ding, Shuang; Dodart, Jean-Cosme
Commun Med.
Apr 2025
10.1038/s43856-025-00870-2
Abstract **Background** The success of passive immunotherapies targeting Calcitonin gene-related peptide (CGRP) for managing migraine has prompted our efforts towards developing an active immunotherapy that induces the production of endogenous antibodies against CGRP. Achieving efficacious antibody titers via immunization could provide a more convenient and cost-effective treatment alternative to anti-CGRP monoclonal antibody (mAb) therapies. However, immunization against endogenous CGRP faces multiple challenges such as breaking immune tolerance, inducing sufficient antibody titers, and avoiding immune response-associated toxicity. **Methods** Synthetic peptide immunogens formulated in adjuvants were delivered intramuscularly. Serum samples were collected post immunization and used to measure antibody titers as well as for the isolation of antibodies specific to CGRP. Antibodies were characterized for their binding affinities and specificities. The capsaicin-induced increase in dermal blood flow model was used in rats for the assessment of the pharmacodynamic effect of immunization. **Results** Here we demonstrate that a peptide-based active immunotherapy designed to induce antibodies against CGRP promotes robust antibody titers across preclinical species. Characterization of the immune response strongly suggests that this peptide immunogen primarily stimulates a humoral response and only induced CGRP-specific antibodies. Antibodies produced by immunization are primarily IgG1 and demonstrate binding and activity potencies similar to marketed monoclonal antibodies against CGRP. Finally, immunization demonstrates in vivo efficacy in a rat pharmacodynamic model. **Conclusion** Our results strongly suggest that a peptide-based active immunotherapy against CGRP could provide an affordable and convenient therapeutic for the prevention of migraine.

Paediatric autoimmune uveitis is associated with intraocular antibodies against Epstein–Barr virus Nuclear Antigen 1 (EBNA-1)

Hendrikse, Jytte; Bont, Louis J.; Schellekens, Peter A.W.J.F.; De Groot-Mijnes, Jolanda D.F.; De Boer, Joke H.; Kuiper, Jonas J.W.
eBioMedicine.
Mar 2025
10.1016/j.ebiom.2025.105681
**Background** Non-infectious uveitis is an immune-mediated disease characterized by vision-threatening inflammation within the eye. Increasing evidence indicates that microbial agents promote non-infectious uveitis, but the natural history of immune responses to pathogens in patients remains unexplored. We determined intraocular antibodies against pathogens in paediatric uveitis. **Methods** We used peptide microarrays containing 3760 linear B-cell epitopes from 196 human pathogens to profile IgG levels in eye fluid biopsies and paired serum samples from 18 Dutch paediatric patients and 6 age-matched controls. We compared intensities of single epitopes and clusters based on overlapping amino acid sequence of peptides. Next-generation sequencing data was obtained to determine the HLA-DRB1∗15:01 genotype. **Findings** Intraocular antibody profiles largely matched serum profiles and were characterized by high IgG against the conserved PALTAVET-motif of enterovirus family members, as well as broad epitope reactivity against Epstein–Barr virus (EBV). The aqueous humour of patients showed elevated levels of antibodies against peptides containing the RRPFFHPV-motif of Epstein–Barr Virus Nuclear Antigen 1 [EBNA-1]. Antibody levels against the RRPFFHPV-motif of EBNA1 were significantly higher in individuals that carry the HLA-DRB1∗15:01 risk allele of paediatric uveitis. **Interpretation** Intraocular antibodies against an immunogenic epitope of EBV showed an association with paediatric uveitis, particularly HLA-DRB1∗15:01 positive uveitis, indicating a potential link between EBV-specific immune responses and autoimmune uveitis. **Funding** Funding for this research was received from Fischer Stichting (UZ2022-3), ODAS (2021-02), LSBS and ANVVB.

HCV immunodominant peptide mapping reveals unique HLA-A*02-restricted signatures: insights for CD8+ T-cell-based vaccines and immunotherapies

Cardoso Corrêa-Dias, Laura; Lopes-Ribeiro, Ágata; Marques-Ferreira, Geovane; Gomes-de-Pontes, Letícia; Pereira-Santos, Thaiza Aline; De Sousa Reis, Erik Vinicius; Silva Moraes, Thaís De Fátima; Assis Martins-Filho, Olindo; Figueiredo Barbosa-Stancioli, Edel; Guimarães Da Fonseca, Flávio; Coelho-dos-Reis, Jordana Grazziela
Immunogenetics.
Jan 2025
10.1007/s00251-025-01370-2
Several barriers for the development of an HCV vaccine still exist, including the genetic diversity of the virus, and the shortage of assessable models for in vitro and in vivo assays. Therefore, in this study, HCV epitope mapping was performed for 59 polyprotein sequences from 7 HCV genotypes. Around 2,880 peptides were considered epitopes for CD8+ T cells. The peptide induction of cytokines from Th1 and/or Th2 axes of the cellular immune response was assessed, indicating a tendency for Th2 axis. In vitro evaluation was performed using peptide microarray and a recombinant HLA-A*02:01 molecule. A total of 615 peptides of high reactivity to HLA-A*02:01 were identified, with predominance of leucine and tryptophan residues, highlighting their importance for TCR-epitope binding and CD8+ T activation. Finally, HCV-derived peptide patterns restricted to HLA-A2*02:01 observed in this study provide important information for the development of a multi-epitope-based pan-genotypic vaccine against the virus.

The antibody repertoire of autoimmune sensory neuronopathies targets pathways of the innate and adaptative immune system. An autoantigenomic approach.

Moritz, Christian P.; Tholance, Yannick; Boutahar, Nadia; Borowczyk, Coralie; Berger, Anne-Emmanuelle; Paul, Stéphane; Antoine, Jean-Christophe; Camdessanché, Jean-Philippe
Journal of Translational Autoimmunity.
Jan 2025
10.1016/j.jtauto.2025.100277
Sensory neuronopathies (SNN) encompasses diverse etiologies, with autoimmunity playing a major role through both cellular and humoral responses. To investigate the humoral autoantibody repertoire in autoimmune SNN, we conducted a retrospective cohort study using large Human Proteome-wide protein microarrays (HuProt 3.1, HuProt 4.0, ProtoArrays). We specifically focused on immune system pathways within the repertoire of targeted antigens (the autoantigenome). We included 131 participants: 44 patients with non-paraneoplastic autoimmune SNN (12 with anti-FGFR3 and/or anti-AGO antibodies), 8 with paraneoplastic SNN and 79 controls. Results were validated in an independent cohort of 16 SNN patients. Overrepresentation of immune-system-related proteins was assessed via the Reactome database, and serum levels of IFN-γ and IL-6 were measured using the Bio-Plex Pro™ Reagent Kit. Autoimmune SNN sera interact with more immune system proteins than healthy controls (ProtoArrays: 271/863 vs. 14/863, HuProt: 112/1694 vs. 39/1694, both p<0.0001). Overrepresentation was observed in all immune sub-pathways, including innate, adaptive immune responses, and cytokine signaling. Anti-FGFR3-positive SNN patients were more reactive with immune system proteins than negative ones. The independent SNN cohort validated the finding of overrepresentatively targeted immune system pathways. Validation with dot blot and ELISA confirmed reactivity to TRIM21 and IL-6, and identified anti-IFN-γ-positive SNN patients. IFN-γ levels correlated weakly with levels of anti-IFN-γ antibodies (Pearson’s r = 0.22, p=0.03). We conclude that the antibody repertoire of autoimmune SNN targets pathways of the innate and adaptative immune system, potentially reflecting key disease-related immune pathways and highlighting the systemic role of immune dysregulation in SNN.

274. Potential HIV vaccine gp41 epitope targeting antibodies identify peptides with similarity to proposed Kawasaki disease related peptide, suggesting non-specific mimotope targeting of acidic amino acid enriched regions

Hakimuddin, Sojar; Baron, Sarah; Hicar, Mark D
Nov 2023
10.1093/ofid/ofad500.346
Abstract Background We have previously isolated a highly mutated (83% homologous to predicted heavy chain germline) antibody (Ab) termed C group 76-Q13-6F5 (6F5) that targets a conformational epitope on gp41. 6F5, though non-neutralizing, has the capacity to mediate Ab dependent cell cytotoxicity (ADCC). When the variable chain (predicted to be VH1-02 derived) was mutated to germline (termed C group 76 ancestor, or 76Canc), surprisingly this Ab still exhibited significant ADCC activity. Many HIV vaccine strategies are focused on raising highly mutated Abs. We propose that there would be an advantage to developing vaccines related to epitopes that permit functional targeting by Abs using germline variable gene sequences. Methods To explore potential protein targets for vaccination strategies to raise and develop such Abs, we interrogated a peptide array of 29,127 linear peptides using PEPperCHIP® Human Epitome Microarray. We then confirmed peptide binding by Western blot and ELISAs. We also assessed binding to CDI laboratories HuProt protein microarray, containing > 21,000 human proteins. Results 76Canc specifically recognized a number of peptides enriched for glutamic and aspartic acid residues (top hit DEEEEYDEDEYEYDE). Meme analysis of positive peptides revealed a peptide sequence most similar to Hepatitis C virus, similar to a peptide implicated in Kawasaki disease (KD). We confirmed specific binding of four of the top peptide hits, including hepatitis C peptide recognition. We then confirmed binding of 76Canc-related Abs to a published optimized KD related peptide (KPAVIPDREALYQDIDEMEEC). Serum from KD and infectious controls was used to compete with biotinylated 76Canc-related Abs. Serum Abs targeting this epitope showed no specific correlation to having KD. Autoantigen screening of 76Canc identified a single human protein of interest that did contain acidic amino acid rich regions.Figure 1:HIV-1 gp41 antibodies recognize peptides similar to peptide implicated in Kawasaki Disease Conclusion This study reveals acidic motif targeting by specific anti-gp41 Abs and the derived germline Ab, but no evidence that these Abs are related to inflammation similar to KD. Cautious development of targeting such Abs by vaccination is warranted. Future structural comparison of these peptides with native proteins and binding competition studies are needed to confirm mimotope binding. Disclosures Mark D. Hicar, MD/PhD, Pfizer: site investigator for 2 trial

Surveillance of SARS-CoV-2 immunogenicity: loss of immunodominant HLA-A*02-restricted epitopes that activate CD8+ T cells

Lopes-Ribeiro, Ágata; Oliveira, Patrícia De Melo; Retes, Henrique Morais; Barbosa-Stancioli, Edel Figueiredo; Da Fonseca, Flávio Guimarães; Tsuji, Moriya; Coelho-dos-Reis, Jordana Grazziela Alves
Front. Immunol..
Nov 2023
10.3389/fimmu.2023.1229712
Introduction and methods In this present work, coronavirus subfamilies and SARS-CoV-2 Variants of Concern (VOCs) were investigated for the presence of MHC-I immunodominant viral peptides using in silico and in vitro tools. Results In our results, HLA-A*02 haplotype showed the highest number of immunodominant epitopes but with the lowest combined prediction score. Furthermore, a decrease in combined prediction score was observed for HLA-A*02-restricted epitopes when the original strain was compared to the VOCs, indicating that the mutations on the VOCs are promoting escape from HLA-A2-mediated antigen presentation, which characterizes a immune evasion process. Additionally, epitope signature analysis revealed major immunogenic peptide loss for structural (S) and non-structural (ORF8) proteins of VOCs in comparison to the Wuhan sequence. Discussion These results may indicate that the antiviral CD8 + T-cell responses generated by original strains could not be sufficient for clearance of variants in either newly or reinfection with SARS-CoV-2. In contrast, N epitopes remain the most conserved and reactive peptides across SARS-CoV-2 VOCs. Overall, our data could contribute to the rational design and development of new vaccinal platforms to induce a broad cellular CD8 + T cell antiviral response, aiming at controlling viral transmission of future SARS-CoV-2 variants.

Anti-Toxin Responses to Natural Enterotoxigenic Escherichia coli (ETEC) Infection in Adults and Children in Bangladesh

Girardi, Petra; Bhuiyan, Taufiqur Rahman; Lundin, Samuel B.; Harutyunyan, Shushan; Neuhauser, Irene; Khanam, Farhana; Nagy, Gábor; Szijártó, Valéria; Henics, Tamás; Nagy, Eszter; Harandi, Ali M.; Qadri, Firdausi
Microorganisms.
Oct 2023
10.3390/microorganisms11102524
A sero-epidemiology study was conducted in Dhaka, Bangladesh between January 2020 and February 2021 to assess the immune responses to ETEC infection in adults and children. (1) Background: Enterotoxigenic Escherichia coli infection is a main cause of diarrheal disease in endemic countries. The characterization of the immune responses evoked by natural infection can guide vaccine development efforts. (2) Methods: A total of 617 adult and 480 pediatric diarrheal patients were screened, and 43 adults and 46 children (below 5 years of age) with an acute ETEC infection completed the study. The plasma samples were analyzed for antibody responses against the ETEC toxins. (3) Results: Heat-stable toxin (ST)-positive ETEC is the main cause of ETEC infection in adults, unlike in children in an endemic setting. We detected very low levels of anti-ST antibodies, and no ST-neutralizing activity. However, infection with ETEC strains expressing the heat-labile toxin (LT) induced systemic antibody responses in less than 25% of subjects. The antibody levels against LTA and LTB, as well as cholera toxin (CT), correlated well. The anti-LT antibodies were shown to have LT- and CT- neutralizing activity. The antibody reactivity against linear LT epitopes did not correlate with toxin-neutralizing activity. (4) Conclusions: Unlike LT, ST is a poor antigen and even adults have low anti-ST antibody levels that do not allow for the detection of toxin-neutralizing activity.

Epitope Mapping of BmpA and BBK32 Borrelia burgdorferi Sensu Stricto Antigens for the Design of Chimeric Proteins with Potential Diagnostic Value

Grąźlewska, Weronika; Holec-Gąsior, Lucyna; Sołowińska, Karolina; Chmielewski, Tomasz; Fiecek, Beata; Contreras, Marinela
ACS Infect. Dis..
Oct 2023
10.1021/acsinfecdis.3c00258

Linear epitope mapping in the E and NS1 proteins of dengue and Zika viruses: Prospection of peptides for vaccines and diagnostics

Aquino, Victor Hugo; Fumagalli, Marcilio J.; Silva, Angélica; De Moura Negrini, Bento Vidal; Rojas, Alejandra; Guillen, Yvalena; Bernal, Cynthia; Figueiredo, Luiz Tadeu Moraes
PLoS ONE.
Oct 2023
10.1371/journal.pone.0292451
The arrival of the Zika virus (ZIKV) in dengue virus (DENV)-endemic areas has posed challenges for both differential diagnosis and vaccine development. Peptides have shown promise in addressing these issues. The aim of this study was to identify the linear epitope profile recognized by serum samples from dengue and Zika patients in the E and NS1 proteins of DENV and ZIKV. This cross-sectional study included individuals of all ages with laboratory-confirmed DENV and ZIKV infections, who were selected through convenience sampling. The serum samples from dengue and Zika patients detected epitopes evenly distributed across the viral proteins in a peptide microarray platform. However, several epitopes were located within “epitope hotspots”, characterized by clusters of peptides recognized in more than 30% of the sub-arrays analyzed using individual or pooled serum samples. The serum samples from dengue and Zika patients showed a high level of cross-reactivity with peptides in the DENV and ZIKV proteins. Analysis using an additional peptide microarray platform, which contained peptides selected based on the results of the initial screening, revealed that two DENV and one ZIKV peptide, highly specific to their related viruses, were located within the epitope hotspots; however, they presented low detection rates (32.5, 35.0, and 28.6%, respectively). In addition, two DENV peptides detected at similarly high rates by both dengue and Zika patients were also found within the epitope hotspots. These hotspots contain several immunodominant epitopes that are recognized by a larger number of individuals when compared to 15-amino acid (aa) sequence peptides. Thus, epitope hotspots may have greater potential to serve as antigens in diagnostic tests and vaccine development than peptides composed of only 15 amino acids.

Quote form