scholarly journals Identification of linear epitopes on the flagellar proteins of Clostridioides difficile

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Razim ◽  
K. Pacyga ◽  
P. Naporowski ◽  
D. Martynowski ◽  
A. Szuba ◽  
...  
Keyword(s):  
Digestive Tract ◽  
In Silico ◽  
Anaerobic Bacterium ◽  
Vaccine Antigen ◽  
Protective Properties ◽  
Clostridioides Difficile ◽  
Vaccine Antigens ◽  
Linear Epitopes ◽  
Flagellar Proteins

AbstractClostridioides difficile (C. difficile) is an opportunistic anaerobic bacterium that causes severe diseases of the digestive tract of humans and animals. One of the possible methods of preventing C. difficile infection is to develop a vaccine. The most promising candidates for vaccine antigens are the proteins involved in the adhesion phenomena. Among them, the FliC and FliD are considered to be suitable candidates. In this paper, the FliC and FliD protein polypeptide epitopes were mapped in silico and by using PEPSCAN procedure. We identified four promising epitopes: 117QRMRTLS123, 205MSKAG209 of FliC and 226NKVAS230, 306TTKKPKD312 of FliD protein. We showed that 117QRMRTLS123 sequence is not only located in TLR5-binding and activating region, as previously shown, but forms an epitope recognized by C. difficile-infected patients’ antibodies. 205MSKAG209 is a C. difficile-unique, immunogenic sequence that forms an exposed epitope on the polymerized flagella structure which makes it a suitable vaccine antigen. 226NKVAS230 and 306TTKKPKD312 are well exposed and possess potential protective properties according to VaxiJen analysis. Our results open the possibility to use these epitopes as suitable anti-C. difficile vaccine antigens.

scholarly journals Use of a Clostridioides difficile Murine Immunization and Challenge Model to Evaluate Single and Combination Vaccine Adjuvants Consisting of Alum and NKT Cell-Activating Ligands

2022 ◽  
Vol 12 ◽  
Author(s):  
Gillian A. Lang ◽  
Kaylee Norman ◽  
Souwelimatou Amadou Amani ◽  
Tyler M. Shadid ◽  
Jimmy D. Ballard ◽  
...  
Keyword(s):  
Immune Responses ◽  
Additional Benefit ◽  
Vaccine Antigen ◽  
Vaccine Adjuvants ◽  
Inkt Cells ◽  
Nkt Cell ◽  
Cell Compartment ◽  
Clostridioides Difficile ◽  
Vaccine Antigens ◽  
The Impact

Adjuvant combinations may enhance or broaden the expression of immune responses to vaccine antigens. Information on whether established Alum type adjuvants can be combined with experimental CD1d ligand adjuvants is currently lacking. In this study, we used a murine Clostridioides difficile immunization and challenge model to evaluate Alum (Alhydrogel™), α-galactosylceramide (α-GC), and one of its analogs 7DW8-5 singly and in combination as vaccine adjuvants. We observed that the Alum/α-GC combination caused modest enhancement of vaccine antigen-specific IgG1 and IgG2b responses, and a broadening to include IgG2c that did not significantly impact overall protection. Similar observations were made using the Alum/7DW8-5 combination. Examination of the impact of adjuvants on NKT cells revealed expansion of invariant NKT (iNKT) cells with modest expansion of their iNKTfh subset and little effect on diverse NKT (dNKT) cells. Side effects of the adjuvants was determined and revealed transient hepatotoxicity when Alum/α-GC was used in combination but not singly. In summary these results showed that the Alum/α-GC or the Alum/7DW8-5 combination could exert distinct effects on the NKT cell compartment and on isotype switch to produce Th1-driven IgG subclasses in addition to Alum/Th2-driven subclasses. While Alum alone was efficacious in stimulating IgG-mediated protection, and α-GC offered no apparent additional benefit in the C. difficile challenge model, the work herein reveals immune response features that could be optimized and harnessed in other vaccine contexts.

scholarly journals Influenza virus hemagglutinin as a vaccine antigen produced in bacteria.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Violetta Sączyńska
Keyword(s):  
Inclusion Bodies ◽  
Vaccine Antigen ◽  
Toll Like Receptor ◽  
Subunit Vaccines ◽  
Designed Proteins ◽  
Influenza Virus Hemagglutinin ◽  
Vaccine Antigens ◽  
Purification Methods ◽  
Correct Structure ◽  
Successful Production

Recombinant subunit vaccines based on hemagglutinin proteins produced in bacteria (bacterial HAs) are promising candidates for enhancing the supply of vaccines against influenza, especially for a pandemic. Over 20 years after the failure to obtain the antigen with native HA characteristics in the early 1980's, there are increasing data on successful production of HA proteins in bacteria. The vast majority of bacterial HAs have been based on the HA1 subunit of HA expressed separately or as a component of conjugate vaccines, but those based on the ectodomain and the HA2 subunit have also been reported. The most of HAs have been efficiently expressed as insoluble aggregates called inclusion bodies. Refolded and purified proteins were extensively studied for structure, the ability to bind to sialic acid-containing receptors, antigenicity, immunogenicity and efficacy. The results from these studies contradict the view that glycosylation determines the correct structure of the hemagglutinin, as they proved that bacterial HAs can be valuable vaccine antigens when appropriate folding and purification methods are applied to rationally designed proteins. The best evidence for success in bacterial production of protective HA is that vaccines based on proprietary Toll-like Receptor (VaxInnate) and bacteriophage Qβ-VLPs (Cytos Biotechnology) technologies have been advanced to clinical studies.

scholarly journals In Silico Analysis of Ixodid Tick Aqauporin-1 Protein as a Candidate Anti-Tick Vaccine Antigen

2019 ◽  
Author(s):  
Christian Ndekezi ◽  
Joseph Nkamwesiga ◽  
Sylvester Ochwo ◽  
Magambo Phillip Kimuda ◽  
Frank Norbert Mwiine ◽  
...  
Keyword(s):  
In Silico ◽  
Prediction Models ◽  
Vaccine Development ◽  
Sequence Similarity ◽  
Vaccine Antigen ◽  
Systematic Research ◽  
Motif Analysis ◽  
Peptide Motifs ◽  
Starting Point ◽  
Tick Vaccine

AbstractTicks are arthropod vectors of pathogens of both Veterinary and Public health importance. Ticks are largely controlled by acaricide application. However, acaricide efficacy is hampered by high cost, the need for regular application and selection of multi-acaricide resistant tick populations. In light of this, future tick control approaches are poised to rely on integration of rational acaricide application and other methods such as vaccination. To contribute to systematic research-guided efforts to produce anti-tick vaccines, we carried out an in silico tick Aquaporin-1 protein (AQP1) analysis to identify unique tick AQP1 peptide motifs that can be used in future peptide anti-tick vaccine development. We used multiple sequence alignment (MSA), motif analysis, homology modeling, and structural analysis to identify unique tick AQP1 peptide motifs. BepiPred, Chou & Fasman-Turn, Karplus & Schulz Flexibility and Parker-Hydrophilicity prediction models were used to asses these motifs’ abilities to induce antibody mediated immune responses. Tick AQP1 (MK334178) protein homology was largely similar to the bovine AQP1 (PDB:1J4N) (23% sequence similarity; Structural superimposition RMS=1.475). The highest similarities were observed in the transmembrane domains while differences were observed in the extra and intra cellular protein loops. Two unique tick AQP1 (MK334178) motifs, M7 (residues 106-125, p=5.4e-25) and M8 (residues 85-104, p=3.3e-24) were identified. These two motifs are located on the extra-cellular AQP1 domain and showed the highest Parker-Hydrophilicity prediction immunogenic scores of 1.153 and 2.612 respectively. The M7 and M8 motifs are a good starting point for the development of potential peptide-based anti-tick vaccine. Further analyses such as in vivo immunization assays are required to validate these findings.

scholarly journals Genetic diversity and epidemiology of accessory gene regulator loci in Clostridioides difficile

2020 ◽  
Vol 2 (7) ◽  
Author(s):  
Yuta Okada ◽  
Shu Okugawa ◽  
Mahoko Ikeda ◽  
Tatsuya Kobayashi ◽  
Ryoichi Saito ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
In Silico ◽  
Type Species ◽  
Clinical Samples ◽  
Pcr Analysis ◽  
Accessory Gene ◽  
Content Type ◽  
Link Type ◽  
Accessory Gene Regulator ◽  
Clostridioides Difficile

Quorum sensing is known to regulate bacterial virulence, and the accessory gene regulator (agr) loci is one of the genetic loci responsible for its regulation. Recent reports examining Clostridioides difficile show that two agr loci, agr1 and agr2, regulate toxin production, but the diversity of agr loci and their epidemiology is unknown. In our study, in silico analysis was performed to research genetic diversity of agr, and C. difficile isolates from clinical samples underwent multilocus sequence typing (MLST) and PCR analysis of agr loci. To reveal the distribution of agr among different strains, phylogenetic analysis was also performed. In our in silico analysis, two different subtypes, named agr2R and agr2M, were found in agr2, which were previously reported. PCR analysis of 133 C . difficile isolates showed that 131 strains had agr1, 61 strains had agr2R, and 26 strains had agr2M; agr2R was mainly found in clade 1 or clade 2 organisms, whereas agr2M was only found in clade 4. With rare exception, agr1-negative sequence types (STs) belonged to clade C-Ⅰ and C-Ⅲ, and one clade 4 strain had agr2R. Our study revealed subtypes of agr2 not previously recognized, and the distribution of several agr loci in C. difficile . These findings provide a foundation for further functional and clinical research of the agr loci.

scholarly journals Characterization of a copper transporter 1 from Dermanyssus gallinae as a vaccine antigen

Parasitology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Sotaro Fujisawa ◽  
Shiro Murata ◽  
Masayoshi Isezaki ◽  
Takuma Ariizumi ◽  
Takumi Sato ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Flow Cytometric Analysis ◽  
Vaccine Antigen ◽  
Economic Losses ◽  
Dermanyssus Gallinae ◽  
Poultry Industry ◽  
Copper Transporter ◽  
Extracellular Region ◽  
Vaccine Antigens ◽  
Copper Transporter 1

Abstract Poultry red mites (Dermanyssus gallinae, PRM) are dangerous ectoparasites that infest chickens and threaten the poultry industry worldwide. PRMs usually develop resistance to chemical acaricides, necessitating the development of more effective preventive agents, and vaccination could be an alternative strategy for controlling PRMs. The suitability of plasma membrane proteins expressed in the midguts as vaccine antigens was evaluated because these molecules are exposed to antibodies in the ingested blood and the binding of antibodies could potentially induce direct damage to midgut tissue and indirect damage via inhibition of the functions of target molecules. Therefore, in the present study, a copper transporter 1-like molecule (Dg-Ctr1) was identified and its efficacy as a vaccine antigen was assessed in vitro. Dg-Ctr1 mRNA was expressed in the midguts and ovaries and in all the life stages, and flow cytometric analysis indicated that Dg-Ctr1 was expressed on the plasma membrane. Importantly, nymphs fed on plasma derived from chickens immunized with the recombinant protein of the extracellular region of Dg-Ctr1 showed a significant reduction in the survival rate. These data indicate that the application of Dg-Ctr1 as a vaccine antigen could reduce the number of nymphs in the farms, contributing to reduction in the economic losses caused by PRMs in the poultry industry. To establish an effective vaccination strategy, the acaricidal effects of the combined use of Dg-Ctr1 with chemical acaricides or other vaccine antigens must be examined.

scholarly journals Use of an Isogenic Mutant Constructed inMoraxella catarrhalis To Identify a Protective Epitope of Outer Membrane Protein B1 Defined by Monoclonal Antibody 11C6

1999 ◽  
Vol 67 (2) ◽  
pp. 681-687 ◽  
Author(s):  
Nicole R. Luke ◽  
Thomas A. Russo ◽  
Neal Luther ◽  
Anthony A. Campagnari
Keyword(s):  
Monoclonal Antibody ◽  
Outer Membrane ◽  
Iron Acquisition ◽  
Outer Membrane Proteins ◽  
Vaccine Antigen ◽  
Effective Vaccine ◽  
Isogenic Mutant ◽  
Vaccine Antigens ◽  
Potential Vaccine

ABSTRACT Moraxella catarrhalis-induced otitis media continues to be a significant cause of infection in young children, prompting increased efforts at identifying effective vaccine antigens. We have previously demonstrated that M. catarrhalis expresses specific outer membrane proteins (OMPs) in response to iron limitation and that this organism can utilize transferrin and lactoferrin for in vitro growth. One of these proteins, which binds human transferrin, is OMP B1. As the human host presents a naturally iron-limited environment, proteins, like OMP B1, which are expressed in response to this nutritional stress are potential vaccine antigens. In this study, we have developed monoclonal antibody (MAb) 11C6, which reacts to a surface-exposed epitope of OMP B1 expressed by M. catarrhalis 7169. This antibody was used to cloneompB1, and sequence analysis suggested that OMP B1 is theM. catarrhalis homologue to the transferrin binding protein B described for pathogenic Neisseriaceae, Haemophilus influenzae, Actinobacillus pleuropneumoniae, andM. catarrhalis. Expression of recombinant OMP B1 on the surface of Escherichia coli confers transferrin binding activity, confirming that this protein is likely involved in iron acquisition. In addition, ompB1 was used to construct an isogenic mutant in M. catarrhalis 7169. This mutant, termed 7169b12, was used as the control in bactericidal assays designed to determine if OMP B1 elicits protective antibodies. In the presence of MAb 11C6 and human complement, wild-type 7169 demonstrated a 99% decline in viability, whereas the ompB1 isogenic mutant was resistant to this bactericidal activity. Further analysis with MAb 11C6 revealed the presence of this OMP B1 epitope on 31% of the clinical isolates tested. These data suggest that OMP B1 is a potential vaccine antigen against M. catarrhalis infections.

scholarly journals Retrospective Definition of Clostridioides difficile PCR Ribotypes on the Basis of Whole Genome Polymorphisms: A Proof of Principle Study

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1078
Author(s):  
Manisha Goyal ◽  
Lysiane Hauben ◽  
Hannes Pouseele ◽  
Magali Jaillard ◽  
Katrien De Bruyne ◽  
...  
Keyword(s):  
In Silico ◽  
Association Studies ◽  
De Bruijn Graph ◽  
Genome Wide Association Studies ◽  
Whole Genome ◽  
Clostridioides Difficile ◽  
Specificity And Sensitivity ◽  
Intergenic Regions ◽  
Pcr Ribotyping ◽  
Proof Of Principle

Clostridioides difficile is a cause of health care-associated infections. The epidemiological study of C. difficile infection (CDI) traditionally involves PCR ribotyping. However, ribotyping will be increasingly replaced by whole genome sequencing (WGS). This implies that WGS types need correlation with classical ribotypes (RTs) in order to perform retrospective clinical studies. Here, we selected genomes of hyper-virulent C. difficile strains of RT001, RT017, RT027, RT078, and RT106 to try and identify new discriminatory markers using in silico ribotyping PCR and De Bruijn graph-based Genome Wide Association Studies (DBGWAS). First, in silico ribotyping PCR was performed using reference primer sequences and 30 C. difficile genomes of the five different RTs identified above. Second, discriminatory genomic markers were sought with DBGWAS using a set of 160 independent C. difficile genomes (14 ribotypes). RT-specific genetic polymorphisms were annotated and validated for their specificity and sensitivity against a larger dataset of 2425 C. difficile genomes covering 132 different RTs. In silico PCR ribotyping was unsuccessful due to non-specific or missing theoretical RT PCR fragments. More successfully, DBGWAS discovered a total of 47 new markers (13 in RT017, 12 in RT078, 9 in RT106, 7 in RT027, and 6 in RT001) with minimum q-values of 0 to 7.40 × 10−5, indicating excellent marker selectivity. The specificity and sensitivity of individual markers ranged between 0.92 and 1.0 but increased to 1 by combining two markers, hence providing undisputed RT identification based on a single genome sequence. Markers were scattered throughout the C. difficile genome in intra- and intergenic regions. We propose here a set of new genomic polymorphisms that efficiently identify five hyper-virulent RTs utilizing WGS data only. Further studies need to show whether this initial proof-of-principle observation can be extended to all 600 existing RTs.

scholarly journals In silico designing of vaccine candidate against Clostridium difficile

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Srijita Basak ◽  
Debashrito Deb ◽  
Utkarsh Narsaria ◽  
Tamalika Kar ◽  
Filippo Castiglione ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
In Silico ◽  
Vaccine Candidate ◽  
Bacterial Colonization ◽  
Expression System ◽  
Docking Studies ◽  
Dynamics Simulation ◽  
Candidate Vaccine ◽  
Main Concern ◽  
Flagellar Proteins

AbstractClostridium difficile is a spore-forming gram-positive bacterium, recognized as the primary cause of antibiotic-associated nosocomial diarrhoea. Clostridium difficile infection (CDI) has emerged as a major health-associated infection with increased incidence and hospitalization over the years with high mortality rates. Contamination and infection occur after ingestion of vegetative spores, which germinate in the gastro-intestinal tract. The surface layer protein and flagellar proteins are responsible for the bacterial colonization while the spore coat protein, is associated with spore colonization. Both these factors are the main concern of the recurrence of CDI in hospitalized patients. In this study, the CotE, SlpA and FliC proteins are chosen to form a multivalent, multi-epitopic, chimeric vaccine candidate using the immunoinformatics approach. The overall reliability of the candidate vaccine was validated in silico and the molecular dynamics simulation verified the stability of the vaccine designed. Docking studies showed stable vaccine interactions with Toll‐Like Receptors of innate immune cells and MHC receptors. In silico codon optimization of the vaccine and its insertion in the cloning vector indicates a competent expression of the modelled vaccine in E. coli expression system. An in silico immune simulation system evaluated the effectiveness of the candidate vaccine to trigger a protective immune response.

scholarly journals Heteropentameric Cholera Toxin B Subunit Chimeric Molecules Genetically Fused to a Vaccine Antigen Induce Systemic and Mucosal Immune Responses: a Potential New Strategy To Target Recombinant Vaccine Antigens to Mucosal Immune Systems

2005 ◽  
Vol 73 (9) ◽  
pp. 5654-5665 ◽  
Author(s):  
Tetsuya Harakuni ◽  
Hideki Sugawa ◽  
Ai Komesu ◽  
Masayuki Tadano ◽  
Takeshi Arakawa
Keyword(s):  
Immune Responses ◽  
Cholera Toxin ◽  
Biologically Active ◽  
Vaccine Antigen ◽  
Cholera Toxin B Subunit ◽  
Protein Fusion ◽  
Immune Systems ◽  
B Subunit ◽  
Vaccine Antigens ◽  
New Strategy

ABSTRACT Noninvasive mucosal vaccines are attractive alternatives to parenteral vaccines. Although the conjugation of vaccine antigens with the B subunit of cholera toxin (CTB) is one of the most promising strategies for vaccine delivery to mucosal immune systems, the molecule cannot tolerate large-protein fusion, as it severely impairs pentamerization and loses affinity for GM1-ganglioside. Here we report a new strategy, in which steric hindrance between CTB-antigen fusion subunits is significantly reduced through the integration of unfused CTB “molecular buffers” into the pentamer unit, making them more efficiently self-assemble into biologically active pentamers. In addition, the chimeric protein took a compact configuration, becoming small enough to be secreted, and one-step affinity-purified proteins, when administered through a mucosal route, induced specific immune responses in mice. Since our results are not dependent on the use of a particular expression system or vaccine antigen, this strategy could be broadly applicable to bacterial enterotoxin-based vaccine design.

scholarly journals Development of a Potent Stabilizer for Long-Term Storage of Foot-and-Mouth Disease Vaccine Antigens

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 252
Author(s):  
Ah-Young Kim ◽  
Hyejin Kim ◽  
Sun Young Park ◽  
Sang Hyun Park ◽  
Jae-Seok Kim ◽  
...  
Keyword(s):  
Foot And Mouth Disease ◽  
Structural Instability ◽  
Mouth Disease ◽  
Candidate Vaccine ◽  
Vaccine Antigen ◽  
Long Term Storage ◽  
Vaccine Antigens ◽  
Foot And Mouth ◽  
Term Storage

A local virus isolate, O/SKR/JC/2014 (O JC), has been considered as a candidate vaccine strain in the development of a domestic foot-and-mouth disease (FMD) vaccine in Korea. However, producing and preserving a sufficient quantity of intact vaccine antigens from the O JC strain was difficult owing to its distinctive structural instability compared to other candidate vaccine strains. Based on this feature, the O JC strain was adopted as a model virus for the stabilization study to determine the optimal stabilizer composition, which enables long-term storage of the FMD vaccine antigen in both aqueous and frozen phases. In contrast to O JC vaccine antigens stored in routinely used Tris-buffered or phosphate-buffered saline, those stored in Tris-KCl buffer showed extended shelf-life at both 4 °C and −70 °C. Additionally, the combined application of 10% sucrose and 5% lactalbumin hydrolysate could protect O JC 146S particles from massive structural breakdown in an aqueous state for up to one year. The stabilizer composition was also effective for other FMDV strains, including serotypes A and Asia 1. With this stabilizer composition, FMD vaccine antigens could be flexibly preserved during the general production process, pending status under refrigeration and banking under ultrafreezing.

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