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

Integrated reiterative pipeline for rapid epitope-based pan-alphavirus vaccines

Versiani, Alice F.; McCaffrey, Peter; Ribeiro-Filho, Helder V.; Silva, Natalia I. O.; Lopes-de-Oliveira, Paulo S.; Carrera, Jean-Paul; Nogueira, Mauricio L.; Marques, Rafael E.; Rossi, Shannan L.; Vasilakis, Nikos
Sci Adv.
Mar 2026
10.1126/sciadv.aeb2066
The vast diversity of the virosphere underscores the need for rapid, adaptable vaccine development infrastructures. Arthropod-borne zoonotic alphaviruses, in particular, continue to pose substantial threats to human and animal health. We present a fast, multitarget vaccine design pipeline integrating machine learning-based epitope prediction, protein modeling, and docking to prioritize viral peptides by immunogenicity, allele coverage, solubility, and stability. T cell epitopes were validated using peptide microarrays and molecular dynamics simulations, confirming receptor binding accuracy. Flow cytometry of murine and human peripheral blood mononuclear cells demonstrated robust T cell activation and cytokine secretion (IFN-γ, TNF-α, or IL-2), dependent on species and HLA allele. Final candidates were selected by composite immunogenicity scores. While this study primarily validates the T cell-specific arm of our predictive pipeline, complementary B cell epitope analyses are ongoing. Our findings support the development of broadly protective pan-alphaviral vaccines and the establishment of efficient, tunable processes for global vaccine development.

Clinical outcomes-dependent IgG epitope profiling in HTLV-1 reveals differential recognition of pathogen-derived antigens

Cilento, Natali Espasiani; Borges, João Vitor Da Silva; Machado, Nicolle Rakanidis; Do Nascimento, Lais Alves; Moreira, Anna Luisa Baratelli; Passos, Lhays Ozório; Santamarina, Aline Boveto; Casseb, Jorge; Sanabani, Sabri Saeed; Victor, Jefferson Russo
Front. Immunol..
Feb 2026
Human T-lymphotropic virus type 1 (HTLV-1) infection presents a wide clinical spectrum ranging from lifelong asymptomatic carriage to severe inflammatory neurodegeneration (HAM/TSP) or adult T-cell leukemia/lymphoma (ATLL). Although IgG responses contribute to viral control and immunopathology, the extent to which HTLV-1 clinical outcomes shape pathogen-derived IgG repertoires remains unclear. In this study, we applied a high-density infectious-disease epitope microarray containing 4,345 linear epitopes from viral, bacterial, parasitic, and fungal pathogens to profile IgG responses in healthy controls (HCs), asymptomatic carriers (ACs), HAM/TSP patients, and ATLL patients. Signal intensities were quantified in arbitrary units, and recognized epitopes were evaluated using similarity clustering (80% identity threshold) to assess repertoire structure. HTLV-1–infected individuals exhibited extensive remodeling of humoral immunity, with marked differences in the breadth and intensity of IgG recognition across clinical groups. HAM/TSP patients displayed broad and high-magnitude responses consistent with chronic inflammation and heightened Th1 activation, whereas ATLL patients recognized the largest number of epitopes but with distinct patterns indicative of altered B-cell regulation. Enhanced IgG responses to Mycobacterium tuberculosis, Strongyloides stercoralis, Toxoplasma gondii, and Plasmodium species were consistent with known co-infection susceptibilities in HTLV-1. Epitope similarity analysis revealed hundreds of low-redundancy clusters across all groups, arguing against simple linear cross-reactivity and suggesting phenotype-specific reshaping of B-cell selection and idiotypic networks. These findings demonstrate that HTLV-1 infection produces distinct, clinically dependent IgG epitope signatures across multiple pathogen classes, with potential relevance for understanding HTLV-1 pathogenesis and informing future studies integrating epitope mapping with B-cell repertoire analysis.

Non-Neutralizing Antibody Functions Predict Susceptibility to SARS-CoV-2 Infection after mRNA Booster Vaccination

Levy, Shlomia; Trifkovic, Sanja; Mielke, Dieter; Oppenheimer, Hannah; Goodman, Derrick; Ostrovsky, Daniel; Sanfield-Oakley, Sherry A.; Brackett, Caroline; Friedman, Lilach M; Kerkau, Melissa; Webby, Richard; Tomaras, Georgia; Guido, Ferrari; Nesher, Lior; Hertz, Tomer
Previous studies have shown that neutralizing and binding antibody titers are correlates of protection for symptomatic SARS-CoV-2 infection. We previously reported that individuals with low IgG and IgA baseline immune history (BIH) to SARS-CoV-2 variants were at increased risk of symptomatic infection in study of healthcare workers that received 3 or 4 doses of the Pfizer BNT-1262b2 vaccine. We also found that 1-month post-vaccination with the 4th booster dose, individuals with low-BIH mounted significant rises in binding and neutralizing antibody titers, to levels comparable to those of individuals with high-BIH, demonstrating that their increased risk was not due to inability to respond to vaccination. To further study the underlying factors that are associated with increased risk, we conducted a systems serology study of 40 low-BIH and 40 high-BIH individuals across 7 months of follow-up. We found that individuals with low BIH exhibited a significantly higher risk of symptomatic infection (HR=2.691, p=0.0065) and mounted weaker IgA and antibody-dependent cellular cytotoxicity (ADCC) responses compared to high-BIH individuals, particularly against Omicron and Delta variants. Baseline levels of the chemokine CXCL-11 were elevated in the low-BIH group. We then showed that baseline immune profiles can be used to train a prediction model of infection risk across 7 months of follow-up with 76% accuracy. IgA, ADCC and ADCP baseline features were dominant predictors of susceptibility. Our findings suggest that non-neutralizing antibody functions, especially IgA and ADCC, contribute to protection against symptomatic SARS-CoV-2 infection and that serology-guided stratification can enhance discovery of immune correlates of risk informing future vaccine design and deployment strategies.

Severity-dependent IgG epitope profiling in COVID-19 reveals differential recognition of pathogen-derived antigens

Do Nascimento, Lais Alves; Machado, NicolleRakanidis; Borges, João Vitor Da Silva; Fagundes, Beatriz Oliveira; Bergamasco, Isabella Siuffi; Sgnotto, Fabio Da Ressureição; Bachi, André Luis Lacerda; Sato, Maria Notomi; Victor, Jefferson Russo
Front. Immunol..
Sep 2025
Background The contribution of antibody-mediated responses to COVID – 19 outcomes remains unclear, particularly regarding cross-reactivity with unrelated pathogens. While co-infections are known to influence disease progression, the broader landscape of IgG reactivity during SARS-CoV-2 infection has not been systematically explored. Methods We employed a high-density peptide microarray containing 4,344 linear epitopes from 37 viruses, 27 bacteria, 17 parasites, and 8 fungi to characterize serum IgG repertoires from individuals with moderate (n = 39) or severe (n = 40) COVID – 19. Controls included pre-pandemic healthy donors and a pooled intravenous immunoglobulin (IVIg) formulation. Data analysis included intensity ranking, epitope mapping, and comparative analysis of mean signal intensities for each epitope between the COVID-Mod and COVID-Sev groups. Results COVID – 19 patients showed widespread IgG reactivity against diverse pathogens, with patterns differing by disease severity. Severe cases displayed broader and more intense reactivity, notably against hepatitis C virus (HCV), SARS-CoV-1, influenza A, Mycobacterium tuberculosis, and Plasmodium falciparum. Moderate cases showed preferential recognition of epitopes from HTLV-I, Neisseria meningitidis, and Trypanosoma cruzi. These findings suggest that SARS-CoV-2 infection modulates pre-existing humoral memory, possibly through epitope spreading or immune reprogramming. Conclusions SARS-CoV-2 infection reshapes the IgG epitope repertoire in a severity-dependent manner, extending to antigens from unrelated pathogens. This phenomenon may reflect underlying immune dysregulation or idiotype-driven interactions. Comprehensive profiling of pathogen-related IgG responses may reveal potential biomarkers of disease severity. This phenomenon may inform future investigations aimed at improving personalized management strategies for co-infected or immunocompromised patients.

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
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.

A tumor-binding antibody with cross-reactivity to viral antigens

Campa, Michael J.; Gottlin, Elizabeth B.; Wiehe, Kevin; Patz, Edward F.
Cancer Immunol Immunother.
Feb 2025
**Background** We previously identified in non-small cell lung cancer (NSCLC) patients an autoantibody to complement factor H (CFH) that is associated with non-metastatic disease and longer time to progression in patients with stage I disease. A recombinant human antibody, GT103, was cloned from single B cells isolated from patients with the autoantibody. GT103 inhibits tumor growth and establishes an antitumor microenvironment. The anti-CFH autoantibody and GT103 recognize the epitope PIDNGDIT within the SCR19 domain of CFH. Here, we asked if this autoantibody could have originally arisen as a humoral response to a similar epitope in a viral protein from a prior infection. **Methods** Homologous viral peptides with high sequence identity to the core PIDNGDIT epitope sequence were identified and synthesized. NSCLC patient plasma containing anti-CFH autoantibodies were assayed by ELISA against these peptides. GT103 was assayed on a 4345-peptide pathogen microarray. **Results** Epitopes similar to the GT103 epitope are present in several viruses, including human metapneumovirus-1 (HMPV-1) that contains a sequence within attachment glycoprotein G that differs by one amino acid. Anti-CFH autoantibodies in NSCLC patient plasma weakly bound to an HMPV-1 peptide containing the epitope. GT103 cross-reacted with multiple viral epitopes on a peptide microarray, with the top hits being peptides in the human endogenous retrovirus-K polymerase (HERV-K pol) protein and measles hemagglutinin glycoprotein. GT103 bound the viral HMPV-1, HERV-K pol, and measles epitope peptides but with lower affinity compared to the GT103 epitope peptide. **Conclusion** These findings suggest that memory B cells against a viral target could have affinity matured to produce an antibody that recognizes a similar epitope on tumor cells and exhibits antitumor properties.

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
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.

Investigation of Immunoreactivity Profiles and Epitope Landscape in Divergent COVID-19 Trajectories and SARS-CoV-2 Variants

Bihani, Surbhi; Ray, Arka; Borishetty, Dhanush; Tuckley, Chaitanya; Salkar, Akanksha; Acharjee, Arup; Shrivastav, Prithviraj; Shrivastav, Om; Shastri, Jayanthi; Agrawal, Sachee; Duttagupta, Siddhartha; Srivastava, Sanjeeva
J. Proteome Res..
Jan 2025
This study aimed to elucidate the complexity of the humoral immune response in COVID-19 patients with varying disease trajectories using a SARS-CoV-2 whole proteome peptide microarray chip. The microarray, containing 5347 peptides spanning the entire SARS-CoV-2 proteome and key variants of concern, was used to analyze IgG responses in 10 severe-to-recovered, 9 nonsevere-to-severe cases, and 10 control case (5 pre-pandemic and 5 SARS-CoV-2-negative) plasma samples. We identified 1151 IgG-reactive peptides corresponding to 647 epitopes, with 207 peptides being cross-reactive across 124 epitopes. Nonstructural protein 3 (nsp3) exhibited the highest number of total and unique epitopes, followed by the spike protein. nsp12 had the most number of cross-reactive epitopes. Peptides from the spike protein and nsps 2, 3, 5, and 13 were notably associated with recovery. Additionally, specific mutations in SARS-CoV-2 variants were found to alter peptide immunoreactivity, with some mutations (e.g., G142D, L452R, and N501Y) enhancing and others (e.g., R190S and E484 K) reducing immune recognition. These findings have critical implications for the development of diagnostics, vaccines, and therapeutics. Understanding the distribution of epitopes and the impact of viral mutations on antigenicity provides insights into immune evasion mechanisms, informing strategies for controlling COVID-19 and future coronavirus outbreaks.

High-throughput identification of immunoreactive peptides and corresponding proteins from Anaplasma platys and Ehrlichia canis using peptide microarray chips

Llanes, Alejandro; Madesh, Swetha; Brangulis, Kalvis; Rajeev, Sreekumari
Front Cell Infect Microbiol.
Jan 2025
10.3389/fcimb.2025.1671309
INTRODUCTION: Anaplasma platys and Ehrlichia canis are rickettsial pathogens infecting dogs, with a worldwide distribution. Both species are obligate intracellular pathogens and colonize bone marrow-derived cells, with coinfections frequently reported in dogs. Although E. canis immunodominant proteins have been thoroughly characterized, very few high-throughput studies have been conducted to identify immunogenic proteins from Anaplasma spp. In this study, we used a methodology based on peptide microarray chips to identify immunoreactive peptides, either shared or species-specific, in the complete theoretical proteomes of both pathogens. METHODS: B-cell epitopes were predicted in the corresponding proteins from both species and ranked for synthesis on the peptide microarrays. These microarrays were screened with serum samples from antibody-positive dogs, as well as negative control sera from unexposed dogs. Additionally, we assessed the feasibility of integrating evidence gathered at the level of individual peptides to identify potentially immunogenic proteins contributing to the patterns of immunoreactivity observed on microarrays. RESULTS: Screening of peptide microarrays resulted in complex antibody reactivity patterns against thousands of peptides. After discarding peptides with cross-reactivity to negative control sera, we identified over 1,200 immunoreactive peptides, including ~80 peptides shared between the two species with almost identical sequences. Despite screening linear peptides, we were able to identify proteins previously reported as immunodominant in E. canis, some of which contain predominantly conformational epitopes. DISCUSSION: Our results suggest that a high-throughput strategy based on peptide microarrays is an effective approach for the rapid identification of immunoreactive peptides and the underlying immunogenic proteins. This study provides a foundation for developing novel diagnostic tools and vaccine candidates against A. platys and E. canis, including potential combined or multivalent formulations targeting both pathogens.

A Quantum Vaccinomics Approach for the Design and Production of MSP4 Chimeric Antigen for the Control of Anaplasma phagocytophilum Infections

de la Fuente, José; Moraga-Fernández, Alberto; Alberdi, Pilar; Díaz-Sánchez, Sandra; García-Álvarez, Olga; Fernández-Melgar, Rubén; Contreras, Marinela
Vaccines.
Nov 2022
Anaplasma phagocytophilum Major surface protein 4 (MSP4) plays a role during infection and multiplication in host neutrophils and tick vector cells. Recently, vaccination trials with the A. phagocytophilum antigen MSP4 in sheep showed only partial protection against pathogen infection. However, in rabbits immunized with MSP4, this recombinant antigen was protective. Differences between rabbit and sheep antibody responses are probably associated with the recognition of non-protective epitopes by IgG of immunized lambs. To address this question, we applied quantum vaccinomics to identify and characterize MSP4 protective epitopes by a microarray epitope mapping using sera from vaccinated rabbits and sheep. The identified candidate protective epitopes or immunological quantum were used for the design and production of a chimeric protective antigen. Inhibition assays of A. phagocytophilum infection in human HL60 and Ixodes scapularis tick ISE6 cells evidenced protection by IgG from sheep and rabbits immunized with the chimeric antigen. These results supported that the design of new chimeric candidate protective antigens using quantum vaccinomics to improve the protective capacity of antigens in multiple hosts.

In silico and in vitro arboviral MHC class I-restricted-epitope signatures reveal immunodominance and poor overlapping patterns

Lopes-Ribeiro, Ágata; Araujo, Franklin Pereira; Oliveira, Patrícia de Melo; Teixeira, Lorena de Almeida; Ferreira, Geovane Marques; Lourenço, Alice Aparecida; Dias, Laura Cardoso Corrêa; Teixeira, Caio Wilker; Retes, Henrique Morais; Lopes, Élisson Nogueira; Versiani, Alice Freitas; Barbosa-Stancioli, Edel Figueiredo; da Fonseca, Flávio Guimarães; Martins-Filho, Olindo Assis; Tsuji, Moriya; Peruhype-Magalhães, Vanessa; Coelho-dos-Reis, Jordana Grazziela Alves
Front. Immunol..
Nov 2022
Introduction The present work sought to identify MHC-I-restricted peptide signatures for arbovirus using in silico and in vitro peptide microarray tools. Methods First, an in-silico analysis of immunogenic epitopes restricted to four of the most prevalent human MHC class-I was performed by identification of MHC affinity score. For that, more than 10,000 peptide sequences from 5 Arbovirus and 8 different viral serotypes, namely Zika (ZIKV), Dengue (DENV serotypes 1-4), Chikungunya (CHIKV), Mayaro (MAYV) and Oropouche (OROV) viruses, in addition to YFV were analyzed. Haplotype HLA-A*02.01 was the dominant human MHC for all arboviruses. Over one thousand HLA-A2 immunogenic peptides were employed to build a comprehensive identity matrix. Intending to assess HLAA*02:01 reactivity of peptides in vitro, a peptide microarray was designed and generated using a dimeric protein containing HLA-A*02:01. Results The comprehensive identity matrix allowed the identification of only three overlapping peptides between two or more flavivirus sequences, suggesting poor overlapping of virus-specific immunogenic peptides amongst arborviruses. Global analysis of the fluorescence intensity for peptide-HLA-A*02:01 binding indicated a dose-dependent effect in the array. Considering all assessed arboviruses, the number of DENV-derived peptides with HLA-A*02:01 reactivity was the highest. Furthermore, a lower number of YFV-17DD overlapping peptides presented reactivity when compared to non-overlapping peptides. In addition, the assessment of HLA-A*02:01-reactive peptides across virus polyproteins highlighted non-structural proteins as “hot-spots”. Data analysis supported these findings showing the presence of major hydrophobic sites in the final segment of non-structural protein 1 throughout 2a (Ns2a) and in nonstructural proteins 2b (Ns2b), 4a (Ns4a) and 4b (Ns4b). Discussion To our knowledge, these results provide the most comprehensive and detailed snapshot of the immunodominant peptide signature for arbovirus with MHC-class I restriction, which may bring insight into the design of future virus-specific vaccines to arboviruses and for vaccination protocols in highly endemic areas.

Cyclic constrained immunoreactive peptides from crucial P. falciparum proteins: potential implications in malaria diagnostics

Vashisht, Kapil; Srivastava, Sukrit; Vandana, Vandana; Das, Ram; Sharma, Supriya; Bhardwaj, Nitin; Anvikar, Anupkumar R; Singh, Susheel Kumar; Kim, Tong-Soo; Na, Byoung-Kuk; Shin, Ho-Joon; Pandey, Kailash C.
Translational Research.
Nov 2022
Malaria is still a global challenge with significant morbidity and mortality, especially in the African, South-East Asian, and Latin American regions. Malaria diagnosis is a crucial pillar in the control and elimination efforts, often accomplished by the administration of mass-scale Rapid diagnostic tests (RDTs). The inherent limitations of RDTs- insensitivity in scenarios of low transmission settings and deletion of one of the target proteins- Histidine rich protein 2/3 (HRP-2/3) are evident from multiple reports, thus necessitating the need to explore novel diagnostic tools/targets. The present study used peptide microarray to screen potential epitopes from 13 antigenic proteins (CSP, EXP1, LSA1, TRAP, AARP, AMA1, GLURP, MSP1, MSP2, MSP3, MSP4, P48/45, HAP2) of P. falciparum. Three cyclic constrained immunoreactive peptides- C6 (EXP1), A8 (MSP2), B7 (GLURP) were identified from 5458 cyclic constrained peptides (in duplicate) against P. falciparum-infected sera. Peptides (C6, A8, B7- cyclic constrained) and (G11, DSQ, NQN- corresponding linear peptides) were fairly immunoreactive towards P. falciparum-infected sera in dot-blot assay. Using direct ELISA, cyclic constrained peptides (C6 and B7) were found to be specific to P. falciparum-infected sera. A substantial number of samples were tested and the peptides successfully differentiated the P. falciparum positive and negative samples with high confidence. In conclusion, the study identified 3 cyclic constrained immunoreactive peptides (C6, B7, and A8) from P. falciparum secretory/surface proteins and further validated for diagnostic potential of 2 peptides (C6 and B7) with field-collected P. falciparum-infected sera samples.

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