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2.
BMC Infect Dis ; 24(1): 886, 2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39210269

ABSTRACT

BACKGROUND: The highly expressed surface antigen 1 (SAG1)-related sequence (SRS) proteins of T. gondii tachyzoites, as a widespread zoonotic parasite, are critical for host cell invasion and represent promising vaccine targets. In this study, we employed a computer-aided multi-method approach for in silico design and evaluation of TgVax452, an epitope-based candidate vaccine against T. gondii tachyzoite-specific SRS proteins. METHODS: Using immunoinformatics web-based tools, structural modeling, and static/dynamic molecular simulations, we identified and screened B- and T-cell immunodominant epitopes and predicted TgVax452's antigenicity, stability, safety, adjuvanticity, and physico-chemical properties. RESULTS: The designed protein possessed 452 residues, a MW of 44.07 kDa, an alkaline pI (6.7), good stability (33.20), solubility (0.498), and antigenicity (0.9639) with no allergenicity. Comprehensive molecular dynamic (MD) simulation analyses confirmed the stable interaction (average potential energy: 3.3799 × 106 KJ/mol) between the TLR4 agonist residues (RS09 peptide) of the TgVax452 in interaction with human TLR4, potentially activating innate immune responses. Also, a dramatic increase was observed in specific antibodies (IgM and IgG), cytokines (IFN-γ), and lymphocyte responses, based on C-ImmSim outputs. Finally, we optimized TgVax452's codon adaptation and mRNA secondary structure for efficient expression in E. coli BL21 expression machinery. CONCLUSION: Our findings suggest that TgVax452 is a promising candidate vaccine against T. gondii tachyzoite-specific SRS proteins and requires further experimental studies for its potential use in preclinical trials.


Subject(s)
Antigens, Protozoan , Computational Biology , Epitopes, T-Lymphocyte , Protozoan Proteins , Protozoan Vaccines , Toxoplasma , Protozoan Proteins/immunology , Protozoan Proteins/genetics , Protozoan Proteins/chemistry , Toxoplasma/immunology , Toxoplasma/genetics , Toxoplasma/chemistry , Protozoan Vaccines/immunology , Protozoan Vaccines/genetics , Antigens, Protozoan/immunology , Antigens, Protozoan/genetics , Antigens, Protozoan/chemistry , Animals , Mice , Epitopes, T-Lymphocyte/immunology , Epitopes, T-Lymphocyte/genetics , Female , Antibodies, Protozoan/immunology , Mice, Inbred BALB C , Epitopes, B-Lymphocyte/immunology , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/chemistry , Humans , Molecular Dynamics Simulation , Immunodominant Epitopes/immunology , Immunodominant Epitopes/genetics , Immunodominant Epitopes/chemistry , Toxoplasmosis/prevention & control , Toxoplasmosis/immunology , Immunoinformatics
3.
Int J Mol Sci ; 25(15)2024 Jul 26.
Article in English | MEDLINE | ID: mdl-39125749

ABSTRACT

Despite successful vaccination efforts, the emergence of new SARS-CoV-2 variants poses ongoing challenges to control COVID-19. Understanding humoral responses regarding SARS-CoV-2 infections and their impact is crucial for developing future vaccines that are effective worldwide. Here, we identified 41 immunodominant linear B-cell epitopes in its spike glycoprotein with an SPOT synthesis peptide array probed with a pool of serum from hospitalized COVID-19 patients. The bioinformatics showed a restricted set of epitopes unique to SARS-CoV-2 compared to other coronavirus family members. Potential crosstalk was also detected with Dengue virus (DENV), which was confirmed by screening individuals infected with DENV before the COVID-19 pandemic in a commercial ELISA for anti-SARS-CoV-2 antibodies. A high-resolution evaluation of antibody reactivity against peptides representing epitopes in the spike protein identified ten sequences in the NTD, RBD, and S2 domains. Functionally, antibody-dependent enhancement (ADE) in SARS-CoV-2 infections of monocytes was observed in vitro with pre-pandemic Dengue-positive sera. A significant increase in viral load was measured compared to that of the controls, with no detectable neutralization or considerable cell death, suggesting its role in viral entry. Cross-reactivity against peptides from spike proteins was observed for the pre-pandemic sera. This study highlights the importance of identifying specific epitopes generated during the humoral response to a pathogenic infection to understand the potential interplay of previous and future infections on diseases and their impact on vaccinations and immunodiagnostics.


Subject(s)
Antibodies, Viral , COVID-19 , Cross Reactions , Dengue Virus , Epitopes, B-Lymphocyte , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Spike Glycoprotein, Coronavirus/immunology , Humans , Cross Reactions/immunology , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/virology , Antibodies, Viral/immunology , Antibodies, Viral/blood , Epitopes, B-Lymphocyte/immunology , Dengue Virus/immunology , Dengue/immunology , Dengue/virology , Antibody-Dependent Enhancement/immunology , Pandemics , Immunodominant Epitopes/immunology
4.
Viruses ; 16(8)2024 Aug 09.
Article in English | MEDLINE | ID: mdl-39205245

ABSTRACT

Neonates are more susceptible to influenza virus infection than adults, resulting in increased morbidity and mortality and delayed clearance of the virus. Generating effective CD8+ T cell responses may be important for improving vaccination outcomes in vulnerable populations, but neonatal T cells frequently respond differently than adult cells. We sought to understand CD8+ T cell specificity and immunodominance during neonatal influenza infection and how any differences from the adult hierarchy might impact peptide vaccine effectiveness. Neonatal C57BL/6 mice displayed an altered CD8+ T cell immunodominance hierarchy during influenza infection, preferentially responding to an epitope in the influenza protein PA rather than the co-dominant adult response to NP and PA. Heterosubtypic infections in mice first infected as pups also displayed altered immunodominance and reduced protection compared to mice first infected as adults. Adoptive transfer of influenza-infected bone-marrow-derived dendritic cells promoted an NP-specific CD8+ T cell response in influenza-virus-infected pups and increased viral clearance. Finally, pups responded to PA (224-233), but not NP (366-374) during peptide vaccination. PA (224-233)-vaccinated mice were not protected during viral challenge. Epitope usage should be considered when designing vaccines that target T cells when the intended patient population includes infants and adults.


Subject(s)
Animals, Newborn , CD8-Positive T-Lymphocytes , Immunodominant Epitopes , Influenza Vaccines , Mice, Inbred C57BL , Orthomyxoviridae Infections , Animals , CD8-Positive T-Lymphocytes/immunology , Mice , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/prevention & control , Influenza Vaccines/immunology , Influenza Vaccines/administration & dosage , Immunodominant Epitopes/immunology , Vaccination , Female , Vaccines, Subunit/immunology , Vaccines, Subunit/administration & dosage , Epitopes, T-Lymphocyte/immunology
5.
Anal Chem ; 96(36): 14524-14530, 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39207871

ABSTRACT

Immunodominant epitope discovery platforms play an important role in identifying novel biomarkers for effective immunotherapies and diagnostics. Methods to analyze the B-cell repertoire have been improved both experimentally and computationally. We developed an enhanced peptide microarray platform to discover and subsequently screen immunodominant epitopes. We utilized SARS-Cov-2 IgG positive and negative samples as a proof-of-concept to demonstrate the power of these improved peptide microarrays. The method identified significantly discriminant epitopes that classify positive and negative samples with good performance both as single peptides and in combination. We provide the assay conditions and parameters that justify the use of peptide microarrays in the selection of high-affinity epitopes, and we directly compare peptide performance against proteins. The results suggest that this platform can be used to confidently identify immunodominant antiviral epitopes while also serving as a useful tool for high-volume screening.


Subject(s)
COVID-19 , Immunodominant Epitopes , Peptides , Protein Array Analysis , SARS-CoV-2 , Protein Array Analysis/methods , Humans , Immunodominant Epitopes/immunology , Immunodominant Epitopes/chemistry , SARS-CoV-2/immunology , Peptides/chemistry , Peptides/immunology , COVID-19/immunology , COVID-19/virology , COVID-19/diagnosis , Immunoglobulin G/immunology , Antibodies, Viral/immunology
6.
Mol Diagn Ther ; 28(5): 633-643, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38980575

ABSTRACT

BACKGROUND AND OBJECTIVE: Dengue is a major infectious disease with potential for outbreaks and epidemics. A specific and sensitive diagnosis is a prerequisite for clinical management of the disease. We designed our study to identify epitopes on the Dengue virus (DENV) envelope (E) and non-structural protein 1 (NS1) with potential for diagnosis. METHODS: Serology and immunoinformatic approaches were employed. We collected DENV-positive, DENV-negative and Japanese encephalitis virus-positive samples from collaborating hospitals in 2019 and 2022-2023. Seropositive peptides in 15-18 mer peptide arrays of E and NS1 proteins of DENV2 were determined by an indirect enzyme-linked immunosorbent assay. B-cell linear and conformational epitopes were predicted using BepiPred2.0 and ElliPro, respectively. A consensus recombinant peptide was designed, synthesised and evaluated for its diagnostic potential using patient sera. RESULTS: Eight peptides of E protein and six peptides of NS1 protein were identified to be the most frequently recognised by Dengue-positive patients. These peptide sequences were compared with B-cell epitope regions and found to be overlapped with predicted B-cell linear and conformational epitopes. EP11 and NSP15 showed a 100% amino acid sequence overlap with B-cell epitopes. EP1 and NSP15 had 14 whereas EP28, EP31, EP60 16, NSP12 and NSP32 had more than 15 interacting interface residues with a neutralising antibody, suggesting a strength of interaction. Interestingly, potential epitopes identified were localised on the surface of proteins as visualised by PyMOL. Validation with a recombined synthetic peptide yielded 92.3% sensitivity and 91.42% specificity. CONCLUSIONS: Immunodominant regions identified by serology and computationally predicted epitopes overlapped, thereby showing the robustness of the methodology and the peptide designed for diagnosis.


Subject(s)
Antibodies, Viral , Dengue Virus , Dengue , Epitopes, B-Lymphocyte , Immunodominant Epitopes , Peptides , Viral Envelope Proteins , Viral Nonstructural Proteins , Viral Nonstructural Proteins/immunology , Humans , Dengue Virus/immunology , Immunodominant Epitopes/immunology , Dengue/diagnosis , Dengue/immunology , Dengue/virology , Dengue/blood , Viral Envelope Proteins/immunology , Viral Envelope Proteins/chemistry , Epitopes, B-Lymphocyte/immunology , Epitopes, B-Lymphocyte/chemistry , Antibodies, Viral/immunology , Antibodies, Viral/blood , Peptides/immunology , Peptides/chemistry , Enzyme-Linked Immunosorbent Assay
7.
Cell Rep ; 43(8): 114530, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39058596

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) first emerged in 2012 and causes human infections in endemic regions. Vaccines and therapeutics in development against MERS-CoV focus on the spike (S) glycoprotein to prevent viral entry into target cells. These efforts are limited by a poor understanding of antibody responses elicited by infection. Here, we analyze S-directed antibody responses in plasma collected from MERS-CoV-infected individuals. We observe that binding and neutralizing antibodies peak 1-6 weeks after symptom onset/hospitalization, persist for at least 6 months, and neutralize human and camel MERS-CoV strains. We show that the MERS-CoV S1 subunit is immunodominant and that antibodies targeting S1, particularly the receptor-binding domain (RBD), account for most plasma neutralizing activity. Antigenic site mapping reveals that plasma antibodies frequently target RBD epitopes, whereas targeting of S2 subunit epitopes is rare. Our data reveal the humoral immune responses elicited by MERS-CoV infection, which will guide vaccine and therapeutic design.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , Middle East Respiratory Syndrome Coronavirus , Spike Glycoprotein, Coronavirus , Spike Glycoprotein, Coronavirus/immunology , Humans , Middle East Respiratory Syndrome Coronavirus/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Animals , Immunodominant Epitopes/immunology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Epitope Mapping , Camelus/immunology , Female
8.
Phys Rev E ; 109(6-1): 064409, 2024 Jun.
Article in English | MEDLINE | ID: mdl-39020898

ABSTRACT

We introduce a multiscale model for affinity maturation, which aims to capture the intraclonal, interclonal, and epitope-specific organization of the B-cell population in a germinal center. We describe the evolution of the B-cell population via a quasispecies dynamics, with species corresponding to unique B-cell receptors (BCRs), where the desired multiscale structure is reflected on the mutational connectivity of the accessible BCR space, and on the statistical properties of its fitness landscape. Within this mathematical framework, we study the competition among classes of BCRs targeting different antigen epitopes, and we construct an effective immunogenic space where epitope immunodominance relations can be universally characterized. We finally study how varying the relative composition of a mixture of antigens with variable and conserved domains allows for a parametric exploration of this space, and we identify general principles for the rational design of two-antigen cocktails.


Subject(s)
Germinal Center , Receptors, Antigen, B-Cell , Germinal Center/immunology , Germinal Center/cytology , Receptors, Antigen, B-Cell/metabolism , Receptors, Antigen, B-Cell/immunology , Models, Immunological , Immunodominant Epitopes/immunology , B-Lymphocytes/immunology
9.
Front Immunol ; 15: 1413893, 2024.
Article in English | MEDLINE | ID: mdl-38915396

ABSTRACT

Introduction: Trypanosoma cruzi is a protozoan parasite that causes the tropical ailment known as Chagas disease, which has its origins in South America. Globally, it has a major impact on health and is transported by insect vector that serves as a parasite. Given the scarcity of vaccines and the limited treatment choices, we conducted a comprehensive investigation of core proteomics to explore a potential reverse vaccine candidate with high antigenicity. Methods: To identify the immunodominant epitopes, T. cruzi core proteomics was initially explored. Consequently, the vaccine sequence was engineered to possess characteristics of non-allergenicity, antigenicity, immunogenicity, and enhanced solubility. After modeling the tertiary structure of the human TLR4 receptor, the binding affinities were assessed employing molecular docking and molecular dynamics simulations (MDS). Results: Docking of the final vaccine design with TLR4 receptors revealed substantial hydrogen bond interactions. A server-based methodology for immunological simulation was developed to forecast the effectiveness against antibodies (IgM + IgG) and interferons (IFN-g). The MDS analysis revealed notable levels of structural compactness and binding stability with average RMSD of 5.03 Aring;, beta-factor 1.09e+5 Å, Rg is 44.7 Aring; and RMSF of 49.50 Aring;. This is followed by binding free energies calculation. The system stability was compromised by the complexes, as evidenced by their corresponding Gibbs free energies of -54.6 kcal/mol. Discussion: Subtractive proteomics approach was applied to determine the antigenic regions of the T cruzi. Our study utilized computational techniques to identify B- and T-cell epitopes in the T. cruzi core proteome. In current study the developed vaccine candidate exhibits immunodominant features. Our findings suggest that formulating a vaccine targeting the causative agent of Chagas disease should be the initial step in its development.


Subject(s)
Chagas Disease , Molecular Docking Simulation , Molecular Dynamics Simulation , Proteome , Protozoan Vaccines , Toll-Like Receptor 4 , Trypanosoma cruzi , Trypanosoma cruzi/immunology , Chagas Disease/immunology , Chagas Disease/prevention & control , Humans , Proteome/immunology , Toll-Like Receptor 4/immunology , Toll-Like Receptor 4/metabolism , Toll-Like Receptor 4/chemistry , Protozoan Vaccines/immunology , Animals , Immunodominant Epitopes/immunology , Proteomics/methods , Antigens, Protozoan/immunology , Antigens, Protozoan/chemistry , Antibodies, Protozoan/immunology , Protozoan Proteins/immunology , Protozoan Proteins/chemistry , Vaccine Development , Epitopes, T-Lymphocyte/immunology , Epitopes, T-Lymphocyte/chemistry
10.
HLA ; 103(6): e15541, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38923358

ABSTRACT

Complications due to HCMV infection or reactivation remain a challenging clinical problem in immunocompromised patients, mainly due to insufficient or absent T-cell functionality. Knowledge of viral targets is crucial to improve monitoring of high-risk patients and optimise antiviral T-cell therapy. To expand the epitope spectrum, genetically-engineered dendritic cells (DCs) and fibroblasts were designed to secrete soluble (s)HLA-A*11:01 and infected with an HCMV mutant lacking immune evasion molecules (US2-6 + 11). More than 700 HLA-A*11:01-restricted epitopes, including more than 50 epitopes derived from a broad range of HCMV open-reading-frames (ORFs) were identified by mass spectrometry and screened for HLA-A*11:01-binding using established prediction tools. The immunogenicity of the 24 highest scoring new candidates was evaluated in vitro in healthy HLA-A*11:01+/HCMV+ donors. Thus, four subdominant epitopes and one immunodominant epitope, derived from the anti-apoptotic protein UL36 and ORFL101C (A11SAL), were identified. Their HLA-A*11:01 complex stability was verified in vitro. In depth analyses revealed highly proliferative and cytotoxic memory T-cell responses against A11SAL, with T-cell responses comparable to the immunodominant HLA-A*02:01-restricted HCMVpp65NLV epitope. A11SAL-specific T cells were also detectable in vivo in immunosuppressed transplant patients and shown to be effective in an in vitro HCMV-infection model, suggesting their crucial role in inhibiting viral replication and improvement of patient's outcome. The developed in vitro pipeline is the first to utilise genetically-engineered DCs to identify naturally presented immunodominant HCMV-derived epitopes. It therefore offers advantages over in silico predictions, is transferable to other HLA alleles, and will significantly expand the repertoire of viral targets to improve therapeutic options.


Subject(s)
Cytomegalovirus Infections , Cytomegalovirus , Dendritic Cells , Epitopes, T-Lymphocyte , Immunodominant Epitopes , Humans , Cytomegalovirus/immunology , Cytomegalovirus Infections/immunology , Immunodominant Epitopes/immunology , Dendritic Cells/immunology , Epitopes, T-Lymphocyte/immunology , HLA-A11 Antigen/immunology , HLA-A11 Antigen/genetics , Fibroblasts/immunology , Fibroblasts/virology , Antigen-Presenting Cells/immunology
11.
J Immunol Methods ; 530: 113697, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38823576

ABSTRACT

Porcine reproductive and respiratory syndrome (PRRS) caused by the PRRS virus (PRRSV) is one of the most severe swine diseases causing great economic losses for the international swine industry. Non-structural protein 4 (NSP4) is critical to the life cycle of PRRSV and contains dominant B cell epitopes. This study prepared a monoclonal antibody against Nsp4, and 2D11, which contained the sequence 138KQGGGIVTRPSGQFCN153, was confirmed as the epitope. A 2D11-based double antibody sandwich enzyme-linked immunosorbent assay (dasELISA) was next developed with a cut value of 0.1987. A total of 1354 pig serum samples were detected by dasELISA and compared to a commercial ELISA kit (N-coated iELISA), resulting in a positive coincidence rate of 98.8% and negative coincidence rate of 96.9%. A total of 119 sera were positive by dasELISA while negative by iELISA. Higher positive rates by dasELISA were found in pig farms where PRRSV antibody levels varied widely. These results indicated that the dasELISA was a useful tool to detect PRRSV antibody in clinical samples.


Subject(s)
Antibodies, Monoclonal , Antibodies, Viral , Enzyme-Linked Immunosorbent Assay , Porcine Reproductive and Respiratory Syndrome , Porcine respiratory and reproductive syndrome virus , Viral Nonstructural Proteins , Porcine respiratory and reproductive syndrome virus/immunology , Animals , Enzyme-Linked Immunosorbent Assay/methods , Swine , Antibodies, Monoclonal/immunology , Porcine Reproductive and Respiratory Syndrome/immunology , Porcine Reproductive and Respiratory Syndrome/diagnosis , Porcine Reproductive and Respiratory Syndrome/blood , Antibodies, Viral/blood , Antibodies, Viral/immunology , Viral Nonstructural Proteins/immunology , Immunodominant Epitopes/immunology , Epitopes, B-Lymphocyte/immunology
12.
Front Immunol ; 15: 1356314, 2024.
Article in English | MEDLINE | ID: mdl-38840924

ABSTRACT

Introduction: Outbreaks of coronaviruses and especially the recent COVID-19 pandemic emphasize the importance of immunological research in this area to mitigate the effect of future incidents. Bioinformatics approaches are capable of providing multisided insights from virus sequencing data, although currently available software options are not entirely suitable for a specific task of mutation surveillance within immunogenic epitopes of SARS-CoV-2. Method: Here, we describe the development of a mutation tracker, EpitopeScan, a Python3 package with command line and graphical user interface tools facilitating the investigation of the mutation dynamics in SARS-CoV-2 epitopes via analysis of multiple-sequence alignments of genomes over time. We provide an application case by examining three Spike protein-derived immunodominant CD4+ T-cell epitopes restricted by HLA-DRB1*04:01, an allele strongly associated with susceptibility to rheumatoid arthritis (RA). Mutations in these peptides are relevant for immune monitoring of CD4+ T-cell responses against SARS-CoV-2 spike protein in patients with RA. The analysis focused on 2.3 million SARS-CoV-2 genomes sampled in England. Results: We detail cases of epitope conservation over time, partial loss of conservation, and complete divergence from the wild type following the emergence of the N969K Omicron-specific mutation in November 2021. The wild type and the mutated peptide represent potential candidates to monitor variant-specific CD4+ T-cell responses. EpitopeScan is available via GitHub repository https://github.com/Aleksandr-biochem/EpitopeScan.


Subject(s)
COVID-19 , Epitopes, T-Lymphocyte , Mutation , SARS-CoV-2 , Software , Spike Glycoprotein, Coronavirus , SARS-CoV-2/immunology , SARS-CoV-2/genetics , Humans , COVID-19/immunology , COVID-19/genetics , COVID-19/virology , Epitopes, T-Lymphocyte/immunology , Epitopes, T-Lymphocyte/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/genetics , CD4-Positive T-Lymphocytes/immunology , Computational Biology/methods , Immunodominant Epitopes/immunology , Immunodominant Epitopes/genetics , Arthritis, Rheumatoid/immunology , Arthritis, Rheumatoid/genetics , HLA-DRB1 Chains/genetics , HLA-DRB1 Chains/immunology
13.
Viruses ; 16(5)2024 05 10.
Article in English | MEDLINE | ID: mdl-38793639

ABSTRACT

African Swine Fever Virus (ASFV) is a large dsDNA virus that encodes at least 150 proteins. The complexity of ASFV and lack of knowledge of effector immune functions and protective antigens have hindered the development of safe and effective ASF vaccines. In this study, we constructed four Orf virus recombinant vectors expressing individual ASFV genes B602L, -CP204L, E184L, and -I73R (ORFVΔ121-ASFV-B602L, -CP204L, -E184L, and -I73R). All recombinant viruses expressed the heterologous ASFV proteins in vitro. We then evaluated the immunogenicity of the recombinants by immunizing four-week-old piglets. In two independent animal studies, we observed high antibody titers against ASFV p30, encoded by CP204L gene. Using Pepscan ELISA, we identified a linear B-cell epitope of 12 amino acids in length (Peptide 15) located in an exposed loop region of p30 as an immunodominant ASFV epitope. Additionally, antibodies elicited against ASFV p30 presented antibody-dependent cellular cytotoxicity (ADCC) activity. These results underscore the role of p30 on antibody responses elicited against ASFV and highlight an important functional epitope that contributes to p30-specific antibody responses.


Subject(s)
African Swine Fever Virus , Antibodies, Viral , Antibody-Dependent Cell Cytotoxicity , Epitopes, B-Lymphocyte , Animals , African Swine Fever/immunology , African Swine Fever/virology , African Swine Fever Virus/immunology , African Swine Fever Virus/genetics , Antibodies, Viral/immunology , Epitopes, B-Lymphocyte/immunology , Epitopes, B-Lymphocyte/genetics , Immunodominant Epitopes/immunology , Immunodominant Epitopes/genetics , Swine , Viral Proteins/immunology , Viral Proteins/genetics , Viral Vaccines/immunology , Viral Vaccines/genetics
14.
Cell Rep ; 43(5): 114235, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38748880

ABSTRACT

Nanoparticle vaccines displaying mosaic receptor-binding domains (RBDs) or spike (S) from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or other sarbecoviruses are used in preparedness against potential zoonotic outbreaks. Here, we describe a self-assembling nanoparticle using lumazine synthase (LuS) as the scaffold to display RBDs from different sarbecoviruses. Mosaic nanoparticles induce sarbecovirus cross-neutralizing antibodies comparable to a nanoparticle cocktail. We find mosaic nanoparticles elicit a B cell receptor repertoire using an immunodominant germline gene pair of IGHV14-3:IGKV14-111. Most of the tested IGHV14-3:IGKV14-111 monoclonal antibodies (mAbs) are broadly cross-reactive to clade 1a, 1b, and 3 sarbecoviruses. Using mAb competition and cryo-electron microscopy, we determine that a representative IGHV14-3:IGKV14-111 mAb, M2-7, binds to a conserved epitope on the RBD, largely overlapping with the pan-sarbecovirus mAb S2H97. This suggests mosaic nanoparticles expand B cell recognition of the common epitopes shared by different clades of sarbecoviruses. These results provide immunological insights into the cross-reactive responses elicited by mosaic nanoparticles against sarbecoviruses.


Subject(s)
Nanoparticles , Nanoparticles/chemistry , Animals , Humans , SARS-CoV-2/immunology , Antibodies, Viral/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Mice , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/chemistry , Cross Reactions/immunology , Antibody Formation/immunology , COVID-19/immunology , COVID-19/virology , Protein Domains , Mice, Inbred BALB C , Multienzyme Complexes/immunology , Female , Immunodominant Epitopes/immunology
15.
Exp Parasitol ; 262: 108772, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38723846

ABSTRACT

The family Sarcocystidae includes several intracellular coccidial parasites such as Toxoplasma gondii, Neospora caninum, Sarcocystis spp. and Hammondia spp. with heteroxenous life cycles involving different parasitic stages (oocysts/sporocysts, tachyzoites and bradyzoites in tissue cysts). The aim of this work was to evaluate monoclonal antibodies (MAb) (anti NcSAG1, anti NcSAG4 and anti TgCC2) and/or polyclonal antibodies (PAb) (anti NcSAG4 and anti TgBAG1) to label specific immunodominant antigens in different parasitic stages of N. caninum (oocyst, bradyzoite and tachyzoite), T. gondii (oocyst, cyst and tachyzoite), H. heydorni (oocyst), S. cruzi (cyst and bradyzoite) and S. falcatula (sporocyst). It was observed that the MAb directed against NcSAG1 reacted exclusively with N. caninum tachyzoites. In contrast, the MAb directed against NcSAG4 did not react with any of the parasites tested at any stage. The MAb directed against NcSAG4 reacted with both N. caninum and T. gondii tachyzoites, T. gondii tissue cysts and S. cruzi tissue cysts and bradyzoites. As expected, the MAb directed against the T. gondii tissue cyst wall antigen TgCC2 reacted with T. gondii tissue cysts, N. caninum bradyzoites, but also with T. gondii and H. heydorni oocysts and S. falcatula sporocysts. Finally, the PAb directed against the T. gondii bradyzoite proteinTgBAG1 reacted with T. gondii tissue cysts, N. caninum bradyzoites, and also with S. cruzi tissue cysts and bradyzoites. These data reveal a wide range of cross-reactions between different species of protozoa and between different developmental stages, which should be taken into account in the design and evaluation of diagnostic tests, as well as in the assessment of vaccination and challenge studies.


Subject(s)
Antibodies, Monoclonal , Antigens, Protozoan , Neospora , Sarcocystis , Toxoplasma , Sarcocystis/immunology , Neospora/immunology , Animals , Antigens, Protozoan/immunology , Toxoplasma/immunology , Antibodies, Monoclonal/immunology , Mice , Sarcocystidae/immunology , Sarcocystidae/growth & development , Immunodominant Epitopes/immunology , Enzyme-Linked Immunosorbent Assay/veterinary , Antibodies, Protozoan/blood , Antibodies, Protozoan/immunology , Mice, Inbred BALB C , Rabbits
16.
Clin Immunol ; 264: 110259, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38768856

ABSTRACT

The gluten-free diet for celiac disease (CeD) is restrictive and often fails to induce complete symptom and/or mucosal disease remission. Central to CeD pathogenesis is the gluten-specific CD4+ T cell that is restricted by HLA-DQ2.5 in over 85% of CeD patients, making HLA-DQ2.5 an attractive target for suppressing gluten-dependent immunity. Recently, a novel anti-HLA-DQ2.5 antibody that specifically recognizes the complexes of HLA-DQ2.5 and multiple gluten epitopes was developed (DONQ52). OBJECTIVE: To assess the ability of DONQ52 to inhibit CeD patient-derived T-cell responses to the most immunogenic gluten peptides that encompass immunodominant T cell epitopes. METHODS: We employed an in vivo gluten challenge model in patients with CeD that affords a quantitative readout of disease-relevant gluten-specific T-cell responses. HLA-DQ2.5+ CeD patients consumed food containing wheat, barley, or rye for 3 days with collection of blood before (D1) and 6 days after (D6) commencing the challenge. Peripheral blood mononuclear cells were isolated and assessed in an interferon (IFN)-γ enzyme-linked immunosorbent spot assay (ELISpot) testing responses to gluten peptides encompassing a series of immunodominant T cell epitopes. The inhibitory effect of DONQ52 (4 or 40 µg/mL) was assessed and compared to pan-HLA-DQ blockade (SPVL3 antibody). RESULTS: In HLA-DQ2.5+ CeD patients, DONQ52 reduced T cell responses to all wheat gluten peptides to an equivalent or more effective degree than pan-HLA-DQ antibody blockade. It reduced T cell responses to a cocktail of the most immunodominant wheat epitopes by a median of 87% (IQR 72-92). Notably, DONQ52 also substantially reduced T-cell responses to dominant barley hordein and rye secalin derived peptides. DONQ52 had no effect on T-cell responses to non-gluten antigens. CONCLUSION: DONQ52 can significantly block HLA-DQ2.5-restricted T cell responses to the most highly immunogenic gluten peptides in CeD. Our findings support in vitro data that DONQ52 displays selectivity and broad cross-reactivity against multiple gluten peptide:HLA-DQ2.5 complexes. This work provides proof-of-concept multi-specific antibody blockade has the potential to meaningfully inhibit pathogenic gluten-specific T-cell responses in CeD and supports ongoing therapeutic development.


Subject(s)
Antibodies, Bispecific , Celiac Disease , Glutens , HLA-DQ Antigens , Humans , Celiac Disease/immunology , Glutens/immunology , HLA-DQ Antigens/immunology , Antibodies, Bispecific/immunology , Antibodies, Bispecific/pharmacology , Female , Epitopes, T-Lymphocyte/immunology , Adult , Male , CD4-Positive T-Lymphocytes/immunology , Peptides/immunology , Middle Aged , T-Lymphocytes/immunology , Interferon-gamma/immunology , Interferon-gamma/metabolism , Immunodominant Epitopes/immunology , Diet, Gluten-Free
17.
Vaccine ; 42(17): 3733-3743, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38705805

ABSTRACT

Hand, foot, and mouth disease (HFMD) poses a significant public health threat primarily caused by four major enteroviruses: enterovirus 71 (EV71), coxsackieviruses A16, A10, and A6. Broadly protective immune responses are essential for complete protection against these major enteroviruses. In this study, we designed a new tetravalent immunogen for HFMD, validated it in silico, in vivo evaluated the immunogenicity of the DNA-based tetravalent vaccine in mice, and identified immunogenic B-cell and T-cell epitopes. A new tetravalent immunogen, VP1me, was designed based on the chimeric protein and epitope-based vaccine principles. It contains a complete EV71 VP1 protein and six reported neutralizing B-cell epitopes derived from the four major enteroviruses causing HFMD. In silico validation using multiple immunoinformatic tools indicated good attributes of the VP1me immunogen suitable for vaccine development. The VP1me-based DNA vaccine efficiently induced both humoral and cellular immune responses in BALB/cAJcl mice. A combination of in silico prediction and immunoassays enabled the identification of immunogenic linear B-cell and CD8 T-cell epitopes within the VP1me immunogen. Immunodominant linear B-cell epitopes were identified in six regions of VP1me, with one epitope located at the N-terminus of the VP1 protein (aa 9-23) regarded as a novel epitope. Interestingly, some B-cell epitopes could also induce the CD8 T-cell response, suggesting their dual functions in immune stimulation. These results lay the groundwork for further development of VP1me as a new vaccine candidate.


Subject(s)
Antibodies, Viral , Epitopes, B-Lymphocyte , Hand, Foot and Mouth Disease , Immunodominant Epitopes , Mice, Inbred BALB C , Vaccines, DNA , Viral Vaccines , Animals , Vaccines, DNA/immunology , Epitopes, B-Lymphocyte/immunology , Hand, Foot and Mouth Disease/prevention & control , Hand, Foot and Mouth Disease/immunology , Mice , Viral Vaccines/immunology , Immunodominant Epitopes/immunology , Antibodies, Viral/immunology , Antibodies, Viral/blood , Female , Epitopes, T-Lymphocyte/immunology , Capsid Proteins/immunology , Capsid Proteins/genetics , Enterovirus/immunology , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/blood , Enterovirus A, Human/immunology , Enterovirus A, Human/genetics , Immunogenicity, Vaccine , Immunity, Cellular , Immunity, Humoral
18.
Virulence ; 15(1): 2360133, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38803081

ABSTRACT

Norovirus (NV) infection causes acute gastroenteritis in children and adults. Upon infection with NV, specific CD8+ T cells, which play an important role in anti-infective immunity, are activated in the host. Owing to the NV's wide genotypic variability, it is challenging to develop vaccines with cross-protective abilities against infection. To aid effective vaccine development, we examined specific CD8+ T-cell responses towards viral-structural protein (VP) epitopes, which enable binding to host susceptibility receptors. We isolated peripheral blood mononuclear cells from 196 participants to screen and identify predominant core peptides towards NV main and small envelope proteins using ex vivo and in vitro intracellular cytokine staining assays. Human leukocyte antigen (HLA) restriction characteristics were detected using next-generation sequencing. Three conservative immunodominant VP-derived CD8+ T-cell epitopes, VP294-102 (TDAARGAIN), VP2153-161 (RGPSNKSSN), and VP1141-148 (FPHIIVDV), were identified and restrictively presented by HLA-Cw * 0102, HLA-Cw * 0702, and HLA-A *1101 alleles, separately. Our findings provide useful insights into the development of future vaccines and treatments for NV infection.


Subject(s)
CD8-Positive T-Lymphocytes , Caliciviridae Infections , Capsid Proteins , Epitopes, T-Lymphocyte , Gastroenteritis , Norovirus , Humans , CD8-Positive T-Lymphocytes/immunology , Capsid Proteins/immunology , Capsid Proteins/genetics , Caliciviridae Infections/immunology , Caliciviridae Infections/virology , Norovirus/immunology , Norovirus/genetics , Adult , Epitopes, T-Lymphocyte/immunology , Epitopes, T-Lymphocyte/genetics , Male , Gastroenteritis/virology , Gastroenteritis/immunology , Female , Middle Aged , Young Adult , Child , Adolescent , Leukocytes, Mononuclear/immunology , Immunodominant Epitopes/immunology , Child, Preschool , Aged
19.
Front Immunol ; 15: 1395870, 2024.
Article in English | MEDLINE | ID: mdl-38799422

ABSTRACT

Emerging infectious diseases represent a significant threat to global health, with West Nile virus (WNV) being a prominent example due to its potential to cause severe neurological disorders alongside mild feverish conditions. Particularly prevalent in the continental United States, WNV has emerged as a global concern, with outbreaks indicating the urgent need for effective prophylactic measures. The current problem is that the absence of a commercial vaccine against WNV highlights a critical gap in preventive strategies against WNV. This study aims to address this gap by proposing a novel, multivalent vaccine designed using immunoinformatics approaches to elicit comprehensive humoral and cellular immune responses against WNV. The objective of the study is to provide a theoretical framework for experimental scientists to formulate of vaccine against WNV and tackle the current problem by generating an immune response inside the host. The research employs reverse vaccinology and subtractive proteomics methodologies to identify NP_041724.2 polyprotein and YP_009164950.1 truncated flavivirus polyprotein NS1 as the prime antigens. The selection process for epitopes focused on B and T-cell reactivity, antigenicity, water solubility, and non-allergenic properties, prioritizing candidates with the potential for broad immunogenicity and safety. The designed vaccine construct integrates these epitopes, connected via GPGPG linkers, and supplemented with an adjuvant with the help of another linker EAAAK, to enhance immunogenicity. Preliminary computational analyses suggest that the proposed vaccine could achieve near-universal coverage, effectively targeting approximately 99.74% of the global population, with perfect coverage in specific regions such as Sweden and Finland. Molecular docking and immune simulation studies further validate the potential efficacy of the vaccine, indicating strong binding affinity with toll-like receptor 3 (TLR-3) and promising immune response profiles, including significant antibody-mediated and cellular responses. These findings present the vaccine construct as a viable candidate for further development and testing. While the theoretical and computational results are promising, advancing from in-silico predictions to a tangible vaccine requires comprehensive laboratory validation. This next step is essential to confirm the vaccine's efficacy and safety in eliciting an immune response against WNV. Through this study, we propose a novel approach to vaccine development against WNV and contribute to the broader field of immunoinformatics, showcasing the potential to accelerate the design of effective vaccines against emerging viral threats. The journey from hypothesis to practical solution embodies the interdisciplinary collaboration essential for modern infectious disease management and prevention strategies.


Subject(s)
Computational Biology , Immunodominant Epitopes , Proteome , Vaccines, Subunit , West Nile Fever , West Nile Virus Vaccines , West Nile virus , West Nile virus/immunology , Immunodominant Epitopes/immunology , Humans , Proteome/immunology , West Nile Fever/prevention & control , West Nile Fever/immunology , West Nile Fever/virology , Computational Biology/methods , West Nile Virus Vaccines/immunology , Vaccines, Subunit/immunology , Vaccine Development , Epitopes, T-Lymphocyte/immunology , Epitopes, B-Lymphocyte/immunology , Proteomics/methods , Immunoinformatics , Protein Subunit Vaccines
20.
Vaccine ; 42(18): 3857-3873, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38616437

ABSTRACT

Dengue becomes the most common life-threatening infectious arbovirus disease globally, with prevalence in the tropical and subtropical areas. The major clinical features include dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS), a condition of hypovolemic shock. Four different serotypes of the dengue virus, known as dengue virus serotype (DENV)- 1, 2, 3 and 4 can infect humans. Only one vaccine is available in the market, named Dengvaxia by Sanofi Pasteur, but there is no desired outcome of this treatment due the antibody dependent enhancement (ADE) of the multiple dengue serotypes. As of now, there is no cure against dengue disease. Our goal in this work was to create a subunit vaccine based on several epitopes that would be effective against every serotype of the dengue virus. Here, computational methods like- immunoinformatics and bioinformatics were implemented to find out possible dominant epitopes. A total of 21 epitopes were chosen using various in-silico techniques from the expected 133 major histocompatibility complex (MHC)- I and major histocompatibility complex (MHC)- II epitopes, along with 95 B-cell epitopes which were greatly conserved. Immune stimulant, non-allergenic and non-toxic immunodominant epitopes (super epitopes) with a suitable adjuvant (Heparin-Binding Hemagglutinin Adhesin, HBHA) were used to construct the vaccine. Following the physicochemical analysis, vaccine construct was docked with Toll-like receptors (TLRs) to predict the immune stimulation. Consequently, the optimal docked complex that demonstrated the least amount of ligand-receptor complex deformability was used to conduct the molecular dynamics analysis. By following the codon optimization, the final vaccine molecule was administered into an expressing vector to perform in-silico cloning. The robust immune responses were generated in the in-silico immune simulation analysis. Hence, this study provides a hope to control the dengue infections. For validation of the immune outcomes, in-vitro as well as in-vivo investigations are essential.


Subject(s)
Dengue Vaccines , Dengue Virus , Dengue , Epitopes, B-Lymphocyte , Serogroup , Dengue Vaccines/immunology , Humans , Dengue Virus/immunology , Dengue/prevention & control , Dengue/immunology , Epitopes, B-Lymphocyte/immunology , Computer Simulation , Vaccines, Subunit/immunology , Computational Biology/methods , Immunodominant Epitopes/immunology , Antibody-Dependent Enhancement/immunology , Epitopes/immunology , Antibodies, Viral/immunology
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