scholarly journals Detection of Immuno Dominant Peptides against pgaB of Acinetobacter baumannii

Author(s):  
M. Indumathi ◽  
A. S. Smiline Girija ◽  
P. Sankar Ganesh ◽  
J. Vijayashree Priyadharsini

Background: Acinetobacter baumannii is a gram negative non-motile coccobacillus, which was considered as a low priority pathogen with low virulence. Recently, it was declared as the priority pathogen under the critical category of the most dangerous pathogen by WHO. Acinetobacter Baumannii is an inhabitant of oral biofilms, and it also increases the risk of refractory periodontitis. It causes nosocomial infections with pgaB, a part of pgaABCD operon which is involved in the biofilm formation. Aim: The aim of the present study was to detect the immunodominant peptides against pgaB of Acinetobacter baumannii using bioinformatic tools and databases. Materials and Methods: The present study was carried out using immune informatics. The protein sequence of the pgaB protein from A.baumannii was subjected to assess allergenicity, secondary structure, antigenicity and stability prediction of selected T cell epitopes, physico-chemical analysis, Identification of MHC class 2 binders, Final selection of B-cell epitopes was done with IEDB B-cell epitope tool Results: Final docking of the peptides were interpreted by hydrogen bonds and interac- tion scores with TLR-2. Promising scores on antigenicity, instability were obtained. Based on the combinatorial scores, one vaccine peptide (LNLTLGLAL) was suggested to be a promising vaccine candidate against pgaB of A.baumannii. Conclusion: The findings of the present study suggest epitope LNLTLGLAL as a promising vaccine candidate against pgaB of A.baumannii. The vaccine peptides targeting the pgaB Gene in A.baumannii using an immune-informatics approach suggests promising results in the present study. However, the predicted epitope peptides need further experimentation in animal models for its application against A.baumannii.

2018 ◽  
Vol 8 ◽  
Author(s):  
Alberto Grandi ◽  
Laura Fantappiè ◽  
Carmela Irene ◽  
Silvia Valensin ◽  
Michele Tomasi ◽  
...  

2018 ◽  
Vol 49 (4) ◽  
pp. 1600-1614 ◽  
Author(s):  
Shudong He ◽  
Jinlong Zhao ◽  
Walid Elfalleh ◽  
Mohamed Jemaà ◽  
Hanju  Sun ◽  
...  

Background/Aims: The incidence of lectin allergic disease is increasing in recent decades, and definitive treatment is still lacking. Identification of B and T-cell epitopes of allergen will be useful in understanding the allergen antibody responses as well as aiding in the development of new diagnostics and therapy regimens for lectin poisoning. In the current study, we mainly addressed these questions. Methods: Three-dimensional structure of the lectin from black turtle bean (Phaseolus vulgaris L.) was modeled using the structural template of Phytohemagglutinin from P. vulgaris (PHA-E, PDB ID: 3wcs.1.A) with high identity. The B and T-cell epitopes were screened and identified by immunoinformatics and subsequently validated by ELISA, lymphocyte proliferation and cytokine profile analyses. Results: Seven potential B-cell epitopes (B1 to B7) were identified by sequence and structure based methods, while three T-cell epitopes (T1 to T3) were identified by the predictions of binding score and inhibitory concentration. The epitope peptides were synthesized. Significant IgE binding capability was found in B-cell epitopes (B2, B5, B6 and B7) and T2 (a cryptic B-cell epitope). T1 and T2 induced significant lymphoproliferation, and the release of IL-4 and IL-5 cytokine confirmed the validity of T-cell epitope prediction. Abundant hydrophobic amino acids were found in B-cell epitope and T-cell epitope regions by amino acid analysis. Positively charged amino acids, such as His residue, might be more favored for B-cell epitope. Conclusion: The present approach can be applied for the identification of epitopes in novel allergen proteins and thus for designing diagnostics and therapies in lectin allergy.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Esther Blanco ◽  
Carolina Cubillos ◽  
Noelia Moreno ◽  
Juan Bárcena ◽  
Beatriz G. de la Torre ◽  
...  

Synthetic peptides incorporating protective B- and T-cell epitopes are candidates for new safer foot-and-mouth disease (FMD) vaccines. We have reported that dendrimeric peptides including four copies of a B-cell epitope (VP1 136 to 154) linked to a T-cell epitope (3A 21 to 35) of FMD virus (FMDV) elicit potent B- and T-cell specific responses and confer protection to viral challenge, while juxtaposition of these epitopes in a linear peptide induces less efficient responses. To assess the relevance of B-cell epitope multivalency, dendrimers bearing two (B2T) or four (B4T) copies of the B-cell epitope from type O FMDV (a widespread circulating serotype) were tested in CD1 mice and showed that multivalency is advantageous over simple B-T-epitope juxtaposition, resulting in efficient induction of neutralizing antibodies and optimal release of IFNγ. Interestingly, the bivalent B2T construction elicited similar or even better B- and T-cell specific responses than tetravalent B4T. In addition, the presence of the T-cell epitope and its orientation were shown to be critical for the immunogenicity of the linear juxtaposed monovalent peptides analyzed in parallel. Taken together, our results provide useful insights for a more accurate design of FMD subunit vaccines.


2021 ◽  
Vol 10 (1) ◽  
pp. 06-13
Author(s):  
Viol Dhea Kharisma ◽  
Arif Nur Muhammad Ansori ◽  
Gabrielle Ann Villar Posa ◽  
Wahyu Choirur Rizky ◽  
Sofy Permana ◽  
...  

Acquired immune deficiency syndrome (AIDS) has been identified from US patients since 1981. AIDS is caused by infection with the human immunodeficiency virus type 1 (HIV-1) which is a retrovirus. HIV-1 gp120 can be recognized by the immune system because it is located outside the virion. The conserved region is identified in gp120, and it is recognized by an immune cell which then initiates specific immune responses, viral mutation escape, and increase vaccine protection coverage, a benefit derived from the conserved region-based vaccine design. However, previous researchers have little knowledge on this conserved region as a target for vaccine design. This paper explains how the conserved region of gp120 HIV-1 is a major target for vaccine design through a bioinformatics approach. The conserved region from gp120 was explored as a vaccine design target with a bioinformatics tool that consists of B-cell epitope mapping, vaccine properties, molecular docking, and dynamic simulation. The peptide vaccine candidate of B5 with the gp120 HIV-1 conserved region was found to provoke B-cell activation through a direct pathway, produce specific antibody, and increase protection from multi-strain viral infection.


2021 ◽  
Vol 26 (5) ◽  
pp. 2901-2915
Author(s):  
SHEREEN F. ELKHOLY ◽  

The rapid outbreak of the new coronavirus SARS-COV-2 has created a major public health challenge. Immunoinformatics tools had a clear effect in tracking the genetic sequence of the virus and monitoring mutations and design vaccines that are effective enough to produce antibodies. In our study, we resorted to the emerging discipline of immunoinformatics in order to design a multi-epitope mRNA vaccine against the spike glycoprotein of SARS-CoV-2. We screened the B cell and T cell epitopes of the Spike glycoprotein. we used ABC pred server to predict B cell epitope in the spike glycoprotein sequence and we used NetMHC-4.1 server to predict the T-cell epitope. Then we selected the B cell and T cell epitopes that fulfilled the antigenicity, non-toxicity, non-allergenicity, induction of both IL4 and IFN gamma. Finally, we designed multi-epitope mRNA Vaccine construct by linking 6 B lymphocytes epitopes (BL) with 6 cytotoxic T lymphocytes epitopes (CTL) together with helper T lymphocyte (HTL) epitope up-streamed by 5’ cap and down-streamed by poly A tail. The vaccine was found to be antigenic, non-toxic, non-allergenic, capable of generating a robust immune response. Based on these parameters, this design can be considered a promising choice for a vaccine against SARS-CoV-2.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Faruku Bande ◽  
Siti Suri Arshad ◽  
Mohd Hair Bejo ◽  
Saeid Kadkhodaei ◽  
Abdul Rahman Omar

Bioinformatic analysis was used to predict antigenic B-cell and T-cell epitopes within the S1 glycoprotein of M41 and CR88 IBV strains. A conserved linear B-cell epitope peptide, YTSNETTDVTS175–185, was identified in M41 IBV strains while three such epitopes types namely, VSNASPNSGGVD279–290, HPKCNFRPENI328–338, and NETNNAGSVSDCTAGT54–69, were predicted in CR88 IBV strains. Analysis of MHCI binding peptides in M41 IBV strains revealed the presence of 15 antigenic peptides out of which 12 were highly conserved in 96–100% of the total M41 strains analysed. Interestingly three of these peptides, GGPITYKVM208, WFNSLSVSI356, and YLADAGLAI472, relatively had high antigenicity index (>1.0). On the other hand, 11 MHCI binding epitope peptides were identified in CR88 IBV strains. Of these, five peptides were found to be highly conserved with a range between 90% and 97%. However, WFNSLSVSL358, SYNISAASV88, and YNISAASVA89 peptides comparably showed high antigenicity scores (>1.0). Combination of antigenic B-cells and T-cells peptides that are conserved across many strains as approach to evoke humoral and CTL immune response will potentially lead to a broad-based vaccine that could reduce the challenges in using live attenuated vaccine technology in the control of IBV infection in poultry.


Immunity ◽  
2004 ◽  
Vol 21 (5) ◽  
pp. 617-627 ◽  
Author(s):  
Ara G. Hovanessian ◽  
Jean-Paul Briand ◽  
Elias A. Said ◽  
Josette Svab ◽  
Stephane Ferris ◽  
...  

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0146951 ◽  
Author(s):  
Rodrigo Nunes Rodrigues-da-Silva ◽  
João Hermínio Martins da Silva ◽  
Balwan Singh ◽  
Jianlin Jiang ◽  
Esmeralda V. S. Meyer ◽  
...  

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Christof C. Smith ◽  
Kelly S. Olsen ◽  
Kaylee M. Gentry ◽  
Maria Sambade ◽  
Wolfgang Beck ◽  
...  

Abstract Background Early in the pandemic, we designed a SARS-CoV-2 peptide vaccine containing epitope regions optimized for concurrent B cell, CD4+ T cell, and CD8+ T cell stimulation. The rationale for this design was to drive both humoral and cellular immunity with high specificity while avoiding undesired effects such as antibody-dependent enhancement (ADE). Methods We explored the set of computationally predicted SARS-CoV-2 HLA-I and HLA-II ligands, examining protein source, concurrent human/murine coverage, and population coverage. Beyond MHC affinity, T cell vaccine candidates were further refined by predicted immunogenicity, sequence conservation, source protein abundance, and coverage of high frequency HLA alleles. B cell epitope regions were chosen from linear epitope mapping studies of convalescent patient serum, followed by filtering for surface accessibility, sequence conservation, spatial localization near functional domains of the spike glycoprotein, and avoidance of glycosylation sites. Results From 58 initial candidates, three B cell epitope regions were identified. From 3730 (MHC-I) and 5045 (MHC-II) candidate ligands, 292 CD8+ and 284 CD4+ T cell epitopes were identified. By combining these B cell and T cell analyses, as well as a manufacturability heuristic, we proposed a set of 22 SARS-CoV-2 vaccine peptides for use in subsequent murine studies. We curated a dataset of ~ 1000 observed T cell epitopes from convalescent COVID-19 patients across eight studies, showing 8/15 recurrent epitope regions to overlap with at least one of our candidate peptides. Of the 22 candidate vaccine peptides, 16 (n = 10 T cell epitope optimized; n = 6 B cell epitope optimized) were manually selected to decrease their degree of sequence overlap and then synthesized. The immunogenicity of the synthesized vaccine peptides was validated using ELISpot and ELISA following murine vaccination. Strong T cell responses were observed in 7/10 T cell epitope optimized peptides following vaccination. Humoral responses were deficient, likely due to the unrestricted conformational space inhabited by linear vaccine peptides. Conclusions Overall, we find our selection process and vaccine formulation to be appropriate for identifying T cell epitopes and eliciting T cell responses against those epitopes. Further studies are needed to optimize prediction and induction of B cell responses, as well as study the protective capacity of predicted T and B cell epitopes.


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