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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.

Immunity to Influenza is dependent on MHC II polymorphism: study with 2 HLA transgenic strains

Luckey, David; Weaver, Eric A.; Osborne, Douglas G.; Billadeau, Daniel D.; Taneja, Veena
Sci Rep.
Dec 2019
Major histocompatibility complex II (MHC II) molecules are involved in antigen presentation and the development of a functional adaptive immune response. Evolutionary selection for MHC molecules that effectively clear infectious agents provides an advantage to humans. However, certain class II molecules are associated with autoimmune diseases. In this study we infected autoimmune-susceptible DRB1*0401.AEo and non-susceptible *0402.AEo mice with H1N1 influenza and determined clearance and protective immunity to H3N2 virus. *0401 mice generated a robust TLR-triggered immune response and cleared H1N1 influenza virus infection. After vaccination and challenge with H1N1, *0401 mice, when challenged with H3N2, generated cross-protective immunity to heterosubtypic H3N2 influenza strain whereas *0402 mice cleared the H1N1 infection but did not generate cross-protective immunity against the H3N2 influenza strain. The intracellular trafficking route of MHCII revealed that *0401 molecules traffic through the late endosome/lysosomes while *0402 molecules traffic into early endosomes. This suggested that trafficking of MHCII could affect the functional output of the innate immune response and clearance of viral infections. Also, DRB1*0401 mice live longer than HLA-DRB1*0402 mice. The study provides a potential hypothesis for evolutionary selection of *0401 molecule, even though it is associated with autoreactivity, which may be dependent on the availability of peptide repertoire of self-antigens.

Analysis of humoral immune responses in chikungunya virus (CHIKV) infected patients and individuals vaccinated with a candidate CHIKV vaccine

Henss, Lisa; Yue, Constanze; von Rhein, Christine; Tschismarov, Roland; Lewis-Ximenez, Lia Laura; Dölle, Albert; Baylis, Sally A; Schnierle, Barbara S
Abstract Background Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes severe flu like symptoms. The acute symptoms disappear after one week, but chronic arthralgia can persist for years. Here, humoral immune responses in CHIKV-infected patients and vaccinees were analyzed. Methods Alphavirus neutralization activity was analyzed with pseudotyped lentiviral vectors and antibody epitope mapping was performed with a peptide array. Results Greatest CHIKV neutralization activity was observed 60-92 days after onset of symptoms. The amount of CHIKV-specific antibodies, their binding avidity and cross-reactivity with other alphaviruses increased over time. CHIKV and o’nyong-nyong virus (ONNV) were both neutralized to a similar extent. Linear antibody binding epitopes were mainly found in E2 domain B and the acid-sensitive regions (ASRs). In addition, serum samples from healthy volunteers vaccinated with a measles-vectored chikungunya vaccine candidate, MV-CHIK, were analyzed. Neutralization activity in the samples from the vaccine cohort was 2–6-fold lower than in samples from CHIKV-infected patients. In contrast to infection, vaccination only induced cross-neutralization with ONNV and the E2 ASR1 was the major antibody target. Conclusion These data could assist vaccine design and enable the identification of correlates of protection necessary for vaccine efficacy.

Predicting HBsAg clearance in genotype A chronic hepatitis B using HBsAg epitope profiling: A biomarker for functional cure

Walsh, Renae; Hammond, Rachel; Yuen, Lilly; Deerain, Joshua; O’Donnell, Tanya; Leary, Thomas; Cloherty, Gavin; Gaggar, Anuj; Kitrinos, Kathryn; Subramanian, Mani; Wong, Darren; Locarnini, Stephen
Liver Int.
Nov 2019
Background and Aim Functional cure is the major goal of chronic hepatitis B (CHB) therapy though few biomarkers predict this outcome. HBsAg epitope occupancy can be influenced by therapeutic and immune pressure. The aim of this study was to map the HBsAg epitope profiles during long-term nucleos(t)ide analogue therapy in patients with genotype A CHB, in the context of HBsAg loss (SL)/seroconversion. Methods We evaluated 25 genotype A CHB patients in the GS-US-174-0103 trial of HBeAg-positive CHB patients treated with tenofovir or adefovir for 4 years, 14 who achieved SL whilst 11 had no change. We epitope mapped the major domains of HBsAg to identify those patients with HBsAg clearance profile (CP) (loss of binding at both loops 1 and 2 epitopes of the ‘a’ determinant) vs non-clearance profile (no change in epitope recognition, or loss of epitope binding at one loop only), correlating this to on-treatment HBsAg responses. Complexed anti-HBs was also measured. Results Analysis of the HBsAg epitope profiles of the 25 patients at baseline identified no predictive correlation with SL. In contrast, analysis at week 48 and end of study (week 192) or prior to SL identified significant predictive associations between development of HBsAg CPs and outcome of functional cure. The detection of a CP also correlated with the development of an alanine aminotransferase flare and detection of anti-HBs complexed with HBsAg. Conclusion The detection of HBsAg CPs by epitope mapping represents a novel viral biomarker, reflecting an emerging anti-HBs selection pressure prior to functional cure.

Immunization of mice with chimeric antigens displaying selected epitopes confers protection against intestinal colonization and renal damage caused by Shiga toxin-producing Escherichia coli

Montero, David A.; Del Canto, Felipe; Salazar, Juan C.; Cespedes, Sandra; Cádiz, Leandro; Arenas-Salinas, Mauricio; Reyes, José; Oñate, Ángel; Vidal, Roberto M.
Sep 2019
Abstract Shiga toxin-producing Escherichia coli (STEC) cause diarrhea and dysentery, which may progress to hemolytic uremic syndrome (HUS). Vaccination has been proposed as a preventive approach against STEC infection; however, there is no vaccine for humans and those used in animals reduce but do not eliminate the intestinal colonization of STEC. The OmpT, Cah and Hes proteins are widely distributed among clinical STEC strains and are recognized by serum IgG and IgA in patients with HUS. Here, we develop a vaccine formulation based on two chimeric antigens containing epitopes of OmpT, Cah and Hes proteins against STEC strains. Intramuscular and intranasal immunization of mice with these chimeric antigens elicited systemic and local long-lasting humoral responses. However, the class of antibodies generated was dependent on the adjuvant and the route of administration. Moreover, while intramuscular immunization with the combination of the chimeric antigens conferred protection against colonization by STEC O157:H7 and the intranasal conferred protection against renal damage caused by STEC O91:H21. This pre-clinical study supports the potential use of this formulation based on recombinant chimeric proteins as a preventive strategy against STEC infections.

A canstatin-derived peptide provides insight into the role of Capillary Morphogenesis Gene 2 in angiogenic regulation and matrix uptake

Finnell, Jordan G.; Tsang, Tsz-Ming; Cryan, Lorna; Garrard, Samuel; Lee, Sai-Lun; Ackroyd, P. Christine; Rogers, Michael S.; Christensen, Kenneth A.
Jul 2019
Abstract Capillary Morphogenesis Gene 2 protein (CMG2) is a transmembrane, integrin-like receptor and the primary receptor for the anthrax toxin. In addition to its role as an anthrax toxin receptor, CMG2 has been repeatedly shown to play a role in angiogenic processes. However, the molecular mechanism mediating observed CMG2-related angiogenic effects has not been fully elucidated. Previous studies have found that CMG2 binds type IV collagen (Col-IV), a key component of the vascular basement membrane, as well as other ECM proteins. Currently, no link has been made between these CMG2-ECM interactions and angiogenesis; however, ECM fragments are known to play a role in regulating angiogenesis. Here, we further characterize the CMG2-Col-IV interaction and explore the effect of this interaction on angiogenesis. Using a peptide array, we observed that CMG2 preferentially binds peptide fragments of the NC1 (non-collagenous domain 1) domains of Col-IV. These domains are also known as the fragments arresten (from the α1 chain) and canstatin (from the α2 chain) and have documented antiangiogenic properties. A second peptide array was probed to map a putative binding epitope. A top hit from the initial array, a canstatin-derived peptide, binds to the CMG2 ligand-binding von Willebrand factor A (vWA) domain with sub-micromolar affinity (peptide S16, K d = 400 ± 200 nM). This peptide competes with anthrax protective antigen (PA) for CMG2 binding, and does not bind CMG2 in the presence of EDTA. Together these data suggest that, like PA, S16 interacts with CMG2 at the metal-ion dependent adhesion site (MIDAS) of its vWA domain. We demonstrate that CMG2 specifically mediates endocytic uptake of S16, since CMG2-/- endothelial cells show markedly reduced S16 uptake, without reducing total endocytosis. Furthermore, we show that S16 reduces endothelial migration but not cell proliferation. Taken together, our data demonstrate that a Col IV-derived anti-angiogenic peptide acts via CMG2, suggesting a possible link between CMG2-Col IV interactions and angiogenesis.

Performance evaluation of 3 serodiagnostic peptide epitopes and the derived multi-epitope peptide OvNMP-48 for detection of Onchocerca volvulus infection

Lagatie, Ole; Verheyen, Ann; Nijs, Erik; Batsa Debrah, Linda; Debrah, Yaw A.; Stuyver, Lieven J.
Parasitol Res.
Jul 2019
Current diagnostic tools to determine infection with the helminth parasite Onchocerca volvulus have limited performance characteristics. In previous studies, a proteome-wide screen was conducted to identify linear epitopes in this parasite’s proteome, resulting in the discovery of 1110 antigenic peptide fragments. Here, we investigated three of these peptides using peptide ELISA’s and evaluated their sensitivity and specificity. Epitope mapping was performed, and peptides were constructed that contained only the minimal epitope, flanked by a linker. Investigation of the performance of these minimal epitope peptides demonstrated that all three of them have a specificity (as defined by lack of response in non-helminth-infected individuals) of 100%, low cross-reactivity (5.6%, 5.6%, and 9.3%, respectively), but low sensitivity (36.9%, 46.5%, and 41.2%, respectively). Some cross-reactivity was observed in samples from individuals infected with soil-transmitted helminths or Brugia malayi. Combining these three minimal epitopes in a single peptide, called OvNMP-48, resulted in a performance that exceeded the sum of the individual epitopes, with a sensitivity of 76.0%, a specificity of 97.4%, and a cross-reactivity of 11.1%. Cross-reactivity was observed in some STH and Brugia malayi-infected individuals. This work opens the opportunity to start exploring how these novel linear epitope markers might become part of the O. volvulus diagnostic toolbox.

LRPAP1 is a frequent proliferation-inducing antigen of BCRs of mantle cell lymphomas and can be used for specific therapeutic targeting

Thurner, Lorenz; Hartmann, Sylvia; Fadle, Natalie; Kemele, Maria; Bock, Theresa; Bewarder, Moritz; Regitz, Evi; Neumann, Frank; Nimmesgern, Anna; von Müller, Lutz; Pott, Christiane; Kim, Yoo-Jin; Bohle, Rainer Maria; Wasik, Mariusz; Schuster, Stephen J.; Hansmann, Martin-Leo; Preuss, Klaus-Dieter; Pfreundschuh, Michael
Leukemia.
Jun 2019
The predominant usage of VH4-34 and V3-21 and reports of stereotyped CDR3s suggest a shared antigenic target of B-cell receptors (BCR) from mantle cell lymphomas (MCL). To identify the target antigens of MCL–BCRs, BCRs from 21 patients and seven MCL cell lines were recombinantly expressed and used for antigen screening. The BCRs from 8/21 patients and 2/7 MCL cell lines reacted specifically with the autoantigen low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1). High-titered and light chain-restricted anti-LRPAP1 serum antibodies were found in MCL patients, but not in controls. LRPAP1 induced proliferation by BCR pathway activation, while an LRPAP1–ETA′ toxin-conjugate specifically killed MCL cells with LRPAP1-specific BCRs. Our results suggest a role of LRPAP1 in lymphomagenesis and maintenance of a considerable proportion of MCL cases by chronic autoantigenic stimulation, likely evolving from a chronic autoreactive B-cell response. Importantly, LRPAP1 can be used for a novel therapeutic approach that targets MCL with LRPAP1-reactive BCRs with high specificity.

Clinical expression and antigenic profiles of a Plasmodium vivax vaccine candidate: merozoite surface protein 7 (PvMSP-7)

Cheng, Chew Weng; Jongwutiwes, Somchai; Putaporntip, Chaturong; Jackson, Andrew P.
Malar J.
Jun 2019
Background Vivax malaria is the predominant form of malaria outside Africa, affecting about 14 million people worldwide, with about 2.5 billion people exposed. Development of a Plasmodium vivax vaccine is a priority, and merozoite surface protein 7 (MSP-7) has been proposed as a plausible candidate. The P. vivax genome contains 12 MSP-7 genes, which contribute to erythrocyte invasion during blood-stage infection. Previous analysis of MSP-7 sequence diversity suggested that not all paralogs are functionally equivalent. To explore MSP-7 functional diversity, and to identify the best vaccine candidate within the family, MSP-7 expression and antigenicity during bloodstream infections were examined directly from clinical isolates. Methods Merozoite surface protein 7 gene expression was profiled using RNA-seq data from blood samples isolated from ten human patients with vivax malaria. Differential expression analysis and co-expression cluster analysis were used to relate PvMSP-7 expression to genetic markers of life cycle stage. Plasma from vivax malaria patients was also assayed using a custom peptide microarray to measure antibody responses against the coding regions of 12 MSP-7 paralogs. Results Ten patients presented diverse transcriptional profiles that comprised four patient groups. Two MSP-7 paralogs, 7A and 7F, were expressed abundantly in all patients, while other MSP-7 genes were uniformly rare (e.g. 7J). MSP-7H and 7I were significantly more abundant in patient group 4 only, (two patients having experienced longer patency), and were co-expressed with a schizont-stage marker, while negatively associated with liver-stage and gametocyte-stage markers. Screening infections with a PvMSP-7 peptide array identified 13 linear B-cell epitopes in five MSP-7 paralogs that were recognized by plasma from all patients. Conclusions These results show that MSP-7 family members vary in expression profile during blood infections; MSP-7A and 7F are expressed throughout the intraerythrocytic development cycle, while expression of other paralogs is focused on the schizont. This may reflect developmental regulation, and potentially functional differentiation, within the gene family. The frequency of B-cell epitopes among paralogs also varies, with MSP-7A and 7L consistently the most immunogenic. Thus, MSP-7 paralogs cannot be assumed to have equal potential as vaccines. This analysis of clinical infections indicates that the most abundant and immunogenic paralog is MSP-7A.

Identification of Two Distinct Linear B Cell Epitopes of the Matrix Protein of the Newcastle Disease Virus Vaccine Strain LaSota

Bi, Youkun; Jin, Zhongyuan; Wang, Yanhong; Mou, Sujing; Wang, Wenbin; Wei, Qiaolin; Huo, Na; Liu, Siqi; Wang, Xinglong; Yang, Zengqi; Chen, Hongjun; Xiao, Sa
Viral Immunology.
Jun 2019
Matrix (M) protein of Newcastle disease virus (NDV) is an abundant protein that can induce a robust humoral immune response. However, its antigenic epitopes remain unknown. In this study, we used a pepscan approach to map linear B cell immunodominant epitopes (IDEs) of M protein with NDV-specific chicken antisera. The six epitopes with the highest reactivity by peptide scanning were obtained as IDE candidates. Among them, aa71–85 and aa349–363 were identified by immunological assays with NDV-specific or IDE-specific antisera. The minimal antigenic epitopes of the two IDEs were further characterized as 77MIDDKP82 and 354HTLAKYNPFK363. Moreover, an amino acid sequence alignment and immunoblot analysis revealed the conservation of the two IDEs in the M protein of strains of different genotypes. These two IDEs of M protein could be genetically eliminated as negative markers in recombinant NDV for serologically differential diagnosis in the development of marker vaccines.

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