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

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.

Differential patterns of cross-reactive antibody response against SARS-CoV-2 spike protein detected for chronically ill and healthy COVID-19 naïve individuals

Jaago, Mariliis; Rähni, Annika; Pupina, Nadežda; Pihlak, Arno; Sadam, Helle; Tuvikene, Jürgen; Avarlaid, Annela; Planken, Anu; Planken, Margus; Haring, Liina; Vasar, Eero; Baćević, Miljana; Lambert, France; Kalso, Eija; Pussinen, Pirkko; Tienari, Pentti J.; Vaheri, Antti; Lindholm, Dan; Timmusk, Tõnis; Ghaemmaghami, Amir M.; Palm, Kaia
Sci Rep.
Oct 2022
Immunity to previously encountered viruses can alter response to unrelated pathogens. We reasoned that similar mechanism may also involve SARS-CoV-2 and thereby affect the specificity and the quality of the immune response against the virus. Here, we employed high-throughput next generation phage display method to explore the link between antibody immune response to previously encountered antigens and spike (S) glycoprotein. By profiling the antibody response in COVID-19 naïve individuals with a diverse clinical history (including cardiovascular, neurological, or oncological diseases), we identified 15 highly antigenic epitopes on spike protein that showed cross-reactivity with antigens of seasonal, persistent, latent or chronic infections from common human viruses. We observed varying degrees of cross-reactivity of different viral antigens with S in an epitope-specific manner. The data show that pre-existing SARS-CoV-2 S1 and S2 cross-reactive serum antibody is readily detectable in pre-pandemic cohort. In the severe COVID-19 cases, we found differential antibody response to the 15 defined antigenic and cross-reactive epitopes on spike. We also noted that despite the high mutation rates of Omicron (B.1.1.529) variants of SARS-CoV-2, some of the epitopes overlapped with the described mutations. Finally, we propose that the resolved epitopes on spike if targeted by re-called antibody response from SARS-CoV-2 infections or vaccinations can function in chronically ill COVID-19 naïve/unvaccinated individuals as immunogenic targets to boost antibodies augmenting the chronic conditions. Understanding the relationships between prior antigen exposure at the antibody epitope level and the immune response to subsequent infections with viruses from a different strain is paramount to guiding strategies to exit the COVID-19 pandemic.

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.

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.

Mapping and Validation of Peptides Differentially Recognized by Antibodies from the Serum of Yellow Fever Virus-Infected or 17DD-Vaccinated Patients

Oliveira, Eneida Santos; Tavares, Naiara Clemente; Colombarolli, Stella Garcia; Batista, Izabella Cristina Andrade; Nascimento, Camila Sales; Felgner, Philip Louis; de Assis, Rafael Ramiro; Calzavara-Silva, Carlos Eduardo
Viruses.
Jul 2022
Yellow Fever disease is caused by the Yellow Fever virus (YFV), an arbovirus from the Flaviviridae family. The re-emergence of Yellow Fever (YF) was facilitated by the increasing urbanization of sylvatic areas, the wide distribution of the mosquito vector, and the low percentage of people immunized in the Americas, which caused severe outbreaks in recent years, with a high mortality rate. Therefore, serological approaches capable of discerning antibodies generated from the wild-type (YFV-WT) strain between the vaccinal strain (YFV-17DD) could facilitate vaccine coverage surveillance, enabling the development of strategies to avoid new outbreaks. In this study, peptides were designed and subjected to microarray procedures with sera collected from individuals infected by WT-YFV and 17DD–YFV of YFV during the Brazilian outbreak of YFV in 2017/2018. From 222 screened peptides, around ten could potentially integrate serological approaches aiming to differentiate vaccinated individuals from naturally infected individuals. Among those peptides, one was synthesized and validated through ELISA.

Multiplex peptide microarray profiling of antibody reactivity against neglected tropical diseases derived B-cell epitopes for serodiagnosis in Zimbabwe

Vengesai, Arthur; Naicker, Thajasvarie; Midzi, Herald; Kasambala, Maritha; Mduluza-Jokonya, Tariro L.; Rusakaniko, Simbarashe; Mutapi, Francisca; Mduluza, Takafira
PLoS ONE.
Jul 2022
Introduction Peptides (B-cell epitopes) have broad applications in disease diagnosis and surveillance of pathogen exposure. In this framework, we present a pilot study to design and produce a peptide microarray for the integrated surveillance of neglected tropical diseases. The peptide microarray was evaluated against peptides derived from Ascaris lumbricoides, Necator americanus, Schistosoma haematobium, Schistosoma mansoni, Trichuris trichiura, Bacillus anthracis, Mycobacterium leprae, Wuchereria bancrofti, Rabies lyssavirus, Chlamydia trachomatis and Trypanosoma brucei. Methods S. haematobium was diagnosed using the urine filtration technique. S. mansoni, A. lumbricoides, N. americanus and T. trichiura were diagnosed using the Kato Katz and formal ether concentration techniques. Immunogenic peptides were retrieved from the Tackling Infection to Benefit Africa infectious diseases epitope microarray. Further peptides were predicted using ABCpred. IgG and IgM reactivity against the derived peptides were evaluated using peptide microarray multiplex immunoassays. Positive response was defined as fluorescence intensity ≥ 500 fluorescence units. Immunodominant peptides were identified using color-coded heat maps and bar graphs reflecting the obtained fluorescence signal intensities. Receiver Operating Characteristic analysis and Mann-Whitney-U test were performed to determine the diagnostic validity of the peptides. Results Species-specific responses with at least one peptide derived from each NTD pathogen were observed. The reactive peptides included; for S. haematobium, XP_035588858.1-206-220 and XP_035588858.1-206-220 immunodominant for IgG and IgM respectively, for S. mansoni, P20287.1-58-72 immunodominant for both antibodies and for T. trichiura, CDW52482.1-326-340 immunodominant for IgG and CDW57769.1-2017-2031 and CDW57769.1-1518-1532 immunodominant for IgM. According to ROC analysis most of the peptides selected were inaccurate; with AUC < 0.5. Some peptides had AUC values ranging from 0.5 to 0.5875 for both IgM and IgG suggesting no discrimination. Conclusion Multiplex peptide microarrays are a valuable tool for integrated NTDs surveillance and for screening parasites exposure in endemic areas. Species sero-reactivity observed in the study maybe indicative of exposure to the different NTDs parasites. However, although peptides with the least cross reactivity were selected there is need to validate the sero-reactivity with recombinant antigens and immune-blotting techniques such as western blotting.

Rise of the SARS-CoV-2 Variants: can proteomics be the silver bullet?

Acharjee, Arup; Stephen Kingsly, Joshua; Kamat, Madhura; Kurlawala, Vishakha; Chakraborty, Aparajita; Vyas, Priyanka; Vaishnav, Radhika; Srivastava, Sanjeeva
Expert Rev Proteomics.
Jun 2022
10.1080/14789450.2022.2085564
INTRODUCTION: The challenges posed by emergent strains of SARS-CoV-2 need to be tackled by contemporary scientific approaches, with proteomics playing a significant role. AREAS COVERED: In this review, we provide a brief synthesis of the impact of proteomics technologies in elucidating disease pathogenesis and classifiers for the prognosis of COVID-19 and propose proteomics methodologies that could play a crucial role in understanding emerging variants and their altered disease pathology. From aiding the design of novel drug candidates to facilitating the identification of T cell vaccine targets, we have discussed the impact of proteomics methods in COVID-19 research. Techniques varied as mass spectrometry, single-cell proteomics, multiplexed ELISA arrays, high-density proteome arrays, surface plasmon resonance, immunopeptidomics, and in silico docking studies that have helped augment the fight against existing diseases were useful in preparing us to tackle SARS-CoV-2 variants. We also propose an action plan for a pipeline to combat emerging pandemics using proteomics technology by adopting uniform standard operating procedures and unified data analysis paradigms. EXPERT OPINION: The knowledge about the use of diverse proteomics approaches for COVID-19 investigation will provide a framework for future basic research, better infectious disease prevention strategies, improved diagnostics, and targeted therapeutics.

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.

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