scholarly journals A Highly Conserved Epitope (RNNQIPQDF) of Porcine teschovirus Induced a Group-Specific Antiserum: A Bioinformatics-Predicted Model with Pan-PTV Potential

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1225
Author(s):  
Tung-Hsuan Tsai ◽  
Chia-Yi Chang ◽  
Fun-In Wang
Keyword(s):  
In Silico ◽  
Neutralizing Antibodies ◽  
Age Groups ◽  
Epitope Prediction ◽  
Toxin B ◽  
Swine Pathogen ◽  
Porcine Teschovirus ◽  
A Subunit ◽  
Predicted Model ◽  
Conserved Epitope

Porcine teschovirus (PTV) is an OIE-listed pathogen with 13 known PTV serotypes. Heterologous PTV serotypes frequently co-circulate and co-infect with another swine pathogen, causing various symptoms in all age groups, thus highlighting the need for a pan-PTV diagnostic tool. Here, a recombinant protein composed of a highly conserved “RNNQIPQDF” epitope on the GH loop of VP1, predicted in silico, and a tandem repeat of this epitope carrying the pan DR (PADRE) and Toxin B epitopes was constructed to serve as a PTV detection tool. This recombinant GST-PADRE-(RNNQIPQDF)n-Toxin B protein was used as an immunogen, which effectively raised non-neutralizing or undetectable neutralizing antibodies against PTV in mice. The raised antiserum was reactive against all the PTV serotypes (PTV–1–7) tested, but not against members of the closely related genera Sapelovirus and Cardiovirus, and the unrelated virus controls. This potential pan-PTV diagnostic reagent may be used to differentiate naturally infected animals from vaccinated animals that have antibodies against a subunit vaccine that does not contain this epitope or to screen for PTV before further subtyping. To our knowledge, this is the first report that utilized in silico PTV epitope prediction to find a reagent broadly reactive to various PTV serotypes.

scholarly journals In silico prediction of a highly immunogenic and conserved epitope against Zika Virus

2021 ◽  
pp. 100613
Author(s):  
Debasish Paul ◽  
Imdadul Haque Sharif ◽  
Abu Sayem ◽  
Hossain Ahmed ◽  
Abu Saleh ◽  
...  
Keyword(s):  
Zika Virus ◽  
In Silico ◽  
In Silico Prediction ◽  
Conserved Epitope

scholarly journals A genetically detoxified derivative of heat-labile Escherichia coli enterotoxin induces neutralizing antibodies against the A subunit.

1994 ◽  
Vol 180 (6) ◽  
pp. 2147-2153 ◽  
Author(s):  
M Pizza ◽  
M R Fontana ◽  
M M Giuliani ◽  
M Domenighini ◽  
C Magagnoli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
Neutralizing Antibodies ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
E Coli ◽  
Heat Labile ◽  
A Subunit ◽  
Adp Ribosyltransferase ◽  
Derivatives Of

Escherichia coli enterotoxin (LT) and the homologous cholera toxin (CT) are A-B toxins that cause travelers' diarrhea and cholera, respectively. So far, experimental live and killed vaccines against these diseases have been developed using only the nontoxic B portion of these toxins. The enzymatically active A subunit has not been used because it is responsible for the toxicity and it is reported to induce a negligible titer of toxin neutralizing antibodies. We used site-directed mutagenesis to inactivate the ADP-ribosyltransferase activity of the A subunit and obtained nontoxic derivatives of LT that elicited a good titer of neutralizing antibodies recognizing the A subunit. These LT mutants and equivalent mutants of CT may be used to improve live and killed vaccines against cholera and enterotoxinogenic E. coli.

scholarly journals In Silico Investigation of the New UK (B.1.1.7) and South African (501Y.V2) SARS-CoV-2 Variants with a Focus at the ACE2–Spike RBD Interface

2021 ◽  
Vol 22 (4) ◽  
pp. 1695
Author(s):  
Bruno O. Villoutreix ◽  
Vincent Calvez ◽  
Anne-Geneviève Marcelin ◽  
Abdel-Majid Khatib
Keyword(s):  
Amino Acid ◽  
South African ◽  
In Silico ◽  
Neutralizing Antibodies ◽  
Viral Escape ◽  
Spike Protein ◽  
Amino Acid Substitutions ◽  
The South ◽  
African Strain ◽  
The Uk

SARS-CoV-2 exploits angiotensin-converting enzyme 2 (ACE2) as a receptor to invade cells. It has been reported that the UK and South African strains may have higher transmission capabilities, eventually in part due to amino acid substitutions on the SARS-CoV-2 Spike protein. The pathogenicity seems modified but is still under investigation. Here we used the experimental structure of the Spike RBD domain co-crystallized with part of the ACE2 receptor, several in silico methods and numerous experimental data reported recently to analyze the possible impacts of three amino acid replacements (Spike K417N, E484K, N501Y) with regard to ACE2 binding. We found that the N501Y replacement in this region of the interface (present in both the UK and South African strains) should be favorable for the interaction with ACE2, while the K417N and E484K substitutions (South African strain) would seem neutral or even unfavorable. It is unclear if the N501Y substitution in the South African strain could counterbalance the K417N and E484K Spike replacements with regard to ACE2 binding. Our finding suggests that the UK strain should have higher affinity toward ACE2 and therefore likely increased transmissibility and possibly pathogenicity. If indeed the South African strain has a high transmission level, this could be due to the N501Y replacement and/or to substitutions in regions located outside the direct Spike–ACE2 interface but not so much to the K417N and E484K replacements. Yet, it should be noted that amino acid changes at Spike position 484 can lead to viral escape from neutralizing antibodies. Further, these amino acid substitutions do not seem to induce major structural changes in this region of the Spike protein. This structure–function study allows us to rationalize some observations made for the UK strain but raises questions for the South African strain.

scholarly journals Distribution and titres of rotavirus antibodies in different age groups

1977 ◽  
Vol 79 (3) ◽  
pp. 365-372 ◽  
Author(s):  
M. M. Elias
Keyword(s):  
Indirect Immunofluorescence ◽  
Acute Gastroenteritis ◽  
Neutralizing Antibodies ◽  
Complement Fixation ◽  
Age Groups ◽  
Newborn Infants ◽  
Older Age ◽  
Human Rotavirus ◽  
Hospital Patients

SUMMARYThree hundred and fifty-seven sera selected at random from hospital patients of all ages were examined for rotavirus antibodies using indirect immunofluorescence (FA) and complement fixation tests (CFT). Three hundred and fourteen of these were also tested for neutralizing antibodies to human rotavirus. Sera from patients admitted with a diagnosis of acute gastroenteritis were excluded from this survey.FA antibodies were found in newborn infants but fell to undetectable titres at 3 months. The highest titres were found in children between the ages of one and three years. In older age groups, the modal titre fell gradually with increasing age until, in sera from those above 70 years of age, FA antibodies were almost undetectable. The same pattern was observed with neutralizing antibodies. A high modal titre of CF antibodies was only found in sera from those aged one to three years.

Pharmacokinetic characterization of recombinant factor XIII (FXIII)-A2 across age groups in patients with FXIII A-subunit congenital deficiency

Haemophilia ◽  
2015 ◽  
Vol 21 (3) ◽  
pp. 380-385 ◽  
Author(s):  
B. Brand-Staufer ◽  
M. Carcao ◽  
B. A. Kerlin ◽  
A. Will ◽  
M. Williams ◽  
...  
Keyword(s):  
Factor Xiii ◽  
Age Groups ◽  
Congenital Deficiency ◽  
A Subunit

scholarly journals A Replicating Single-Cycle Adenovirus Vaccine Effective against Clostridium difficile

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 470
Author(s):  
William E. Matchett ◽  
Stephanie Anguiano-Zarate ◽  
Goda Baddage Rakitha Malewana ◽  
Haley Mudrick ◽  
Melissa Weldy ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Neutralizing Antibodies ◽  
Antibody Responses ◽  
Complete Protection ◽  
Single Cycle ◽  
Toxin B ◽  
Toxin Binding ◽  
Binding Domains ◽  
Binding Antibody

Clostridium difficile causes nearly 500,000 infections and nearly 30,000 deaths each year in the U.S., which is estimated to cost $4.8 billion. C. difficile infection (CDI) arises from bacteria colonizing the large intestine and releasing two toxins, toxin A (TcdA) and toxin B (TcdB). Generating humoral immunity against C. difficile’s toxins provides protection against primary infection and recurrence. Thus, a vaccine may offer the best opportunity for sustained, long-term protection. We developed a novel single-cycle adenovirus (SC-Ad) vaccine against C. difficile expressing the receptor-binding domains from TcdA and TcdB. The single immunization of mice generated sustained toxin-binding antibody responses and protected them from lethal toxin challenge for up to 38 weeks. Immunized Syrian hamsters produced significant toxin-neutralizing antibodies that increased over 36 weeks. Single intramuscular immunization provided complete protection against lethal BI/NAP1/027 spore challenge 45 weeks later. These data suggest that this replicating vaccine may prove useful against CDI in humans.

scholarly journals In silico analysis of epitope-based CadF vaccine design against Campylobacter jejuni

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mona Moballegh Naseri ◽  
Saeed Shams ◽  
Mohammad Moballegh Naseri ◽  
Bita Bakhshi
Keyword(s):  
Campylobacter Jejuni ◽  
In Silico ◽  
Vaccine Development ◽  
In Silico Analysis ◽  
Effective Vaccine ◽  
Suitable Structure ◽  
A Subunit ◽  
Bioinformatics Study ◽  
Theoretical Results ◽  
Silico Analysis

Abstract Objective Vaccination is an important strategy for the eradication of infectious diseases. CadF protein of Campylobacter jejuni is one of the important factors in the pathogenesis of this bacterium. The purpose of this work was to perform a bioinformatics study to identify an epitope-based CadF vaccine, as a subunit vaccine. Full protein sequences of CadF were extracted from the NCBI and UniProt databases and subjected to in silico evaluations, including sequence analysis, allergenicity, antigenicity, epitope conservancy, and molecular docking assessments done by different servers. Results The results showed that CadF was a highly conserved protein belonging to the outer member proteins superfamily. Among the evaluated epitopes, LSDSLALRL was identified as an antigenic and non-allergenic peptide with a suitable structure for vaccine development. It was also able to stimulate both T and B cells. This 9-mer peptide was located in 136–144 segment of CadF protein and interacted with both HLA-A 0101 and HLA-DRB1 0101 alleles. Overall, the obtained theoretical results showed that CadF protein could be used for designing and evaluating a new effective vaccine against C. jejuni.

scholarly journals Incidence of Infection of Enterovirus 71 and Coxsackieviruses A6 and A16 among Household Contacts of Index Cases in Dong Thap Province, Southern Vietnam

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
C. Q. Hoang ◽  
H. D. Nguyen ◽  
N. X. Ho ◽  
T. H. T. Vu ◽  
T. T. M. Pham ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Age Groups ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Household Contacts ◽  
Significant Difference ◽  
Antibody Titers ◽  
Index Cases

Background. Scarce information exists about immunity to hand, foot, and mouth disease (HFMD) among household contacts of index cases in Vietnam and what that means for reducing ongoing HFMD transmission in the community. Methods. We analyzed neutralizing antibodies (NT) and the incidence of enterovirus (EVs) infection among household contacts of index cases in a province where HFMD remains endemic. Throat swab and 2 mL blood samples from household contacts were collected at enrollment, during and after 2 weeks follow-up. Results. The incidence of EV-A71 infection among household contacts was 40/84 (47.6%, 95% Cl: 36.9-58.3%), compared with 106/336 (31.5%, 95% Cl: 26.6-36.5%) for CV-A6 and 36/107 (33.6%, 95% Cl: 24.7-42.6%) for CV-A16. The incidence of CV-A6 infection was fairly constant across ages; in contrast, CV-A71 and CV-A16 had some variation across ages. At baseline, higher geometric mean titer (GMT) of EV-A71, CV-A6, and CV-A16 antibody titers was found for 25-34-year groups (range 216.3 to 305.0) compared to the other age groups. There was a statistically significant difference in GMT values of CV-A6 and CV-A16 between those who had an infection or did not have infection among households with an index case of these serotypes. Conclusions. Our results indicated that adults were becoming infected with HFMD and could be contributing to the transmission. There is, therefore, a need for considering the household setting as an additional target for intervention programs for HFMD.

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