scholarly journals In Silico Prediction of T and B Cell Epitopes of SAG1-Related Sequence 3 (SRS3) Gene for Developing Toxoplasma gondii Vaccine

2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Abolfazl Mirzadeh ◽  
Geita Saadatnia ◽  
Majid Golkar ◽  
Jalal Babaie ◽  
Samira Amiri ◽  
...  

: Toxoplasmosis is a worldwide infection that can lead to serious problems in immune-compromised individuals and fetuses. A DNA vaccine strategy would be an ideal tool against Toxoplasma gondii. One of the necessary measures to provide an effective vaccine is the selection of proteins with high antigenicity. The SAG1-related sequence 3 (SRS3) protein is a major surface antigen in T. gondii that can be used as a vaccine candidate. In the present study, bioinformatics and computational methods were utilized to predict protein characteristics, as well as secondary and tertiary structures. The in silico approach is highly suited to analyze, design, and evaluate DNA vaccine strategies. Hence, in silico prediction was used to identify B and T cell epitopes and compare the antigenicity of SRS3 and other candidate genes of Toxoplasma previously applied in the production of vaccines. The results of the analysis theoretically showed that SRS3 has multiple epitopes with high antigenicity, proposing that SRS3 is a promising immunogenic candidate for the development of DNA vaccines against toxoplasmosis.

2007 ◽  
Vol 76 (3) ◽  
pp. 1223-1229 ◽  
Author(s):  
Henriette Macmillan ◽  
Junzo Norimine ◽  
Kelly A. Brayton ◽  
Guy H. Palmer ◽  
Wendy C. Brown

ABSTRACTThe outer membrane proteins (OMPs) of bacterial pathogens are essential for their growth and survival and especially for attachment and invasion of host cells. Since the outer membrane is the interface between the bacterium and the host cell, outer membranes and individual OMPs are targeted for development of vaccines against many bacterial diseases. Whole outer membrane fractions often protect against disease, and this protection cannot be fully reproduced by using individual OMPs. Exactly how the interactions among individual OMPs influence immunity is not well understood. We hypothesized that one OMP rich in T-cell epitopes can act as a carrier for an associated OMP which is poor in T-cell epitopes to generate T-dependent antibody responses, similar to the hapten-carrier effect. Major surface protein 1a (MSP1a) and MSP1b1 occur as naturally complexed OMPs in theAnaplasma marginaleouter membrane. Previous studies demonstrated that immunization with the native MSP1 heteromer induced strong immunoglobulin G (IgG) responses to both proteins, but only MSP1a stimulated strong CD4+T-cell responses. Therefore, to test our hypothesis, constructs of CD4+T-cell epitopes from MSP1a linked to MSP1b1 were compared with individually administered MSP1a and MSP1b1 for induction of MSP1b-specific IgG. By linking the T-cell epitopes from MSP1a to MSP1b1, significantly higher IgG titers against MSP1b1 were induced. Understanding how the naturally occurring intermolecular interactions between OMPs influence the immune response may lead to more effective vaccine design.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1582
Author(s):  
Zhengqing Yu ◽  
Yujia Lu ◽  
Wandi Cao ◽  
Muhammad Tahir Aleem ◽  
Junlong Liu ◽  
...  

The pathogen of toxoplasmosis, Toxoplasma gondii (T. gondii), is a zoonotic protozoon that can affect the health of warm-blooded animals including humans. Up to now, an effective vaccine with completely protection is still inaccessible. In this study, the DNA vaccine encoding T. gondii histone deacetylase SIR2 (pVAX1-SIR2) was constructed. To enhance the efficacy, chitosan and poly (d, l-lactic-co-glycolic)-acid (PLGA) were employed to design nanospheres loaded with the DNA vaccine, denoted as pVAX1-SIR2/CS and pVAX1-SIR2/PLGA nanospheres. The pVAX1-SIR2 plasmids were transfected into HEK 293-T cells, and the expression was evaluated by a laser scanning confocal microscopy. Then, the immune protections of pVAX1-SIR2 plasmid, pVAX1-SIR2/CS nanospheres, and pVAX1-SIR2/PLGA nanospheres were evaluated in a laboratory animal model. The in vivo findings indicated that pVAX1-SIR2/CS and pVAX1-SIR2/PLGA nanospheres could generate a mixed Th1/Th2 immune response, as indicated by the regulated production of antibodies and cytokines, the enhanced maturation and major histocompatibility complex (MHC) expression of dendritic cells (DCs), the induced splenocyte proliferation, and the increased percentages of CD4+ and CD8+ T lymphocytes. Furthermore, this enhanced immunity could obviously reduce the parasite burden in immunized animals through a lethal dose of T. gondii RH strain challenge. All these results propose that pVAX1-SIR2 plasmids entrapped in chitosan or PLGA nanospheres could be the promising vaccines against acute T. gondii infections and deserve further investigations.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Muhammad Tahir ul Qamar ◽  
Farah Shahid ◽  
Sadia Aslam ◽  
Usman Ali Ashfaq ◽  
Sidra Aslam ◽  
...  

Abstract Background Coronavirus disease 2019 (COVID-19) linked with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause severe illness and life-threatening pneumonia in humans. The current COVID-19 pandemic demands an effective vaccine to acquire protection against the infection. Therefore, the present study was aimed to design a multiepitope-based subunit vaccine (MESV) against COVID-19. Methods Structural proteins (Surface glycoprotein, Envelope protein, and Membrane glycoprotein) of SARS-CoV-2 are responsible for its prime functions. Sequences of proteins were downloaded from GenBank and several immunoinformatics coupled with computational approaches were employed to forecast B- and T- cell epitopes from the SARS-CoV-2 highly antigenic structural proteins to design an effective MESV. Results Predicted epitopes suggested high antigenicity, conserveness, substantial interactions with the human leukocyte antigen (HLA) binding alleles, and collective global population coverage of 88.40%. Taken together, 276 amino acids long MESV was designed by connecting 3 cytotoxic T lymphocytes (CTL), 6 helper T lymphocyte (HTL) and 4 B-cell epitopes with suitable adjuvant and linkers. The MESV construct was non-allergenic, stable, and highly antigenic. Molecular docking showed a stable and high binding affinity of MESV with human pathogenic toll-like receptors-3 (TLR3). Furthermore, in silico immune simulation revealed significant immunogenic response of MESV. Finally, MEV codons were optimized for its in silico cloning into the Escherichia coli K-12 system, to ensure its increased expression. Conclusion The MESV developed in this study is capable of generating immune response against COVID-19. Therefore, if designed MESV further investigated experimentally, it would be an effective vaccine candidate against SARS-CoV-2 to control and prevent COVID-19.


2008 ◽  
Vol 52 (4) ◽  
pp. 231-242 ◽  
Author(s):  
Songsak Tongchusak ◽  
Chanvit Leelayuwat ◽  
Vladimir Brusic ◽  
Sansanee C. Chaiyaroj

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Onyeka S. Chukwudozie ◽  
Rebecca C. Chukwuanukwu ◽  
Onyekachi O. Iroanya ◽  
Daniel M. Eze ◽  
Vincent C. Duru ◽  
...  

The novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has previously never been identified with humans, thereby creating devastation in public health. The need for an effective vaccine to curb this pandemic cannot be overemphasized. In view of this, we designed a subcomponent antigenic peptide vaccine targeting the N-terminal (NT) and C-terminal (CT) RNA binding domains of the nucleocapsid protein that aid in viral replication. Promising antigenic B cell and T cell epitopes were predicted using computational pipelines. The peptides “RIRGGDGKMKDL” and “AFGRRGPEQTQGNFG” were the B cell linear epitopes with good antigenic index and nonallergenic property. Two CD8+ and Three CD4+ T cell epitopes were also selected considering their safe immunogenic profiling such as allergenicity, antigen level conservancy, antigenicity, peptide toxicity, and putative restrictions to a number of MHC-I and MHC-II alleles. With these selected epitopes, a nonallergenic chimeric peptide vaccine incapable of inducing a type II hypersensitivity reaction was constructed. The molecular interaction between the Toll-like receptor-5 (TLR5) which was triggered by the vaccine was analyzed by molecular docking and scrutinized using dynamics simulation. Finally, in silico cloning was performed to ensure the expression and translation efficiency of the vaccine, utilizing the pET-28a vector. This research, therefore, provides a guide for experimental investigation and validation.


2020 ◽  
Author(s):  
Onyeka S. Chukwudozie ◽  
Rebecca C. Chukwuanukwu ◽  
Iroanya O. Onyekachi ◽  
Eze M. Daniel ◽  
Duru C. Vincent ◽  
...  

ABSTRACTThe novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has previously never been identified with humans, thereby creating devastation in public health. The need for an effective vaccine to curb this pandemic cannot be overemphasized. In view of this, we, therefore, designed a subcomponent antigenic peptide vaccine targeting the N-terminal (NT) and C-terminal (CT) RNA binding domains of nucleocapsid protein that aid in viral replication. Promising antigenic B-cells and T cell epitopes were predicted using computational pipelines. The peptides “RIRGGDGKMKDL” and “AFGRRGPEQTQGNFG” were the B cell linear epitopes with good antigenic index and non-allergenic property. Two CD8+ and Three CD4+ T-cell epitopes were also selected considering their safe immunogenic profiling such as allergenicity, antigen level conservancy, antigenicity, peptide toxicity, and putative restrictions to a number of MHC-I and II alleles. With these selected epitopes, a non-allergenic chimeric peptide vaccine incapable of inducing a Type II hypersensitivity reaction was constructed. The molecular interaction between the toll-like receptor-5 (TLR5) which was triggered by the vaccine was analyzed by molecular docking and scrutinized using dynamics simulation. Finally, in silico cloning was performed to ensure the expression and translation efficiency of the vaccine, utilizing pET-28a vector. This research, therefore, provides a guide for experimental investigation and validation.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Masoud Foroutan ◽  
Ali Dalir Ghaffari ◽  
Shahrzad Soltani ◽  
Hamidreza Majidiani ◽  
Ali Taghipour ◽  
...  

Abstract Objectives Toxoplasma gondii (T. gondii), an obligate intracellular apicomplexan parasite, could affect numerous warm-blooded animals, such as humans. Calcium-dependent protein kinases (CDPKs) are essential Ca2+ signaling mediators and participate in parasite host cell egress, outer membrane motility, invasion, and cell division. Results Several bioinformatics online servers were employed to analyze and predict the important properties of CDPK4 protein. The findings revealed that CDPK4 peptide has 1158 amino acid residues with average molecular weight (MW) of 126.331 KDa. The aliphatic index and GRAVY for this protein were estimated at 66.82 and – 0.650, respectively. The findings revealed that the CDPK4 protein comprised 30.14% and 34.97% alpha-helix, 59.84% and 53.54% random coils, and 10.02% and 11.49% extended strand with SOPMA and GOR4 tools, respectively. Ramachandran plot output showed 87.87%, 8.40%, and 3.73% of amino acid residues in the favored, allowed, and outlier regions, respectively. Also, several potential B and T-cell epitopes were predicted for CDPK4 protein through different bioinformatics tools. Also, antigenicity and allergenicity evaluation demonstrated that this protein has immunogenic and non-allergenic nature. This paper presents a basis for further studies, thereby provides a fundamental basis for the development of an effective vaccine against T. gondii infection.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Ana Clara Barbosa Antonelli ◽  
Vinnycius Pereira Almeida ◽  
Fernanda Oliveira Feitosa de Castro ◽  
Jacyelle Medeiros Silva ◽  
Irmtraut Araci Hoffmann Pfrimer ◽  
...  

AbstractZika virus (ZIKV) is an arbovirus from the Flaviviridae family and Flavivirus genus. Neurological events have been associated with ZIKV-infected individuals, such as Guillain-Barré syndrome, an autoimmune acute neuropathy that causes nerve demyelination and can induce paralysis. With the increase of ZIKV infection incidence in 2015, malformation and microcephaly cases in newborns have grown considerably, which suggested congenital transmission. Therefore, the development of an effective vaccine against ZIKV became an urgent need. Live attenuated vaccines present some theoretical risks for administration in pregnant women. Thus, we developed an in silico multiepitope vaccine against ZIKV. All structural and non-structural proteins were investigated using immunoinformatics tools designed for the prediction of CD4 + and CD8 + T cell epitopes. We selected 13 CD8 + and 12 CD4 + T cell epitopes considering parameters such as binding affinity to HLA class I and II molecules, promiscuity based on the number of different HLA alleles that bind to the epitopes, and immunogenicity. ZIKV Envelope protein domain III (EDIII) was added to the vaccine construct, creating a hybrid protein domain-multiepitope vaccine. Three high scoring continuous and two discontinuous B cell epitopes were found in EDIII. Aiming to increase the candidate vaccine antigenicity even further, we tested secondary and tertiary structures and physicochemical parameters of the vaccine conjugated to four different protein adjuvants: flagellin, 50S ribosomal protein L7/L12, heparin-binding hemagglutinin, or RS09 synthetic peptide. The addition of the flagellin adjuvant increased the vaccine's predicted antigenicity. In silico predictions revealed that the protein is a probable antigen, non-allergenic and predicted to be stable. The vaccine’s average population coverage is estimated to be 87.86%, which indicates it can be administered worldwide. Peripheral Blood Mononuclear Cells (PBMC) of individuals with previous ZIKV infection were tested for cytokine production in response to the pool of CD4 and CD8 ZIKV peptide selected. CD4 + and CD8 + T cells showed significant production of IFN-γ upon stimulation and IL-2 production was also detected by CD8 + T cells, which indicated the potential of our peptides to be recognized by specific T cells and induce immune response. In conclusion, we developed an in silico universal vaccine predicted to induce broad and high-coverage cellular and humoral immune responses against ZIKV, which can be a good candidate for posterior in vivo validation.


2021 ◽  
Vol 10 (1) ◽  
pp. 59
Author(s):  
Ali Dalir Ghaffari ◽  
Abdolhossein Dalimi ◽  
Fatemeh Ghaffarifar ◽  
Majid Pirestani ◽  
Hamidreza Majidiani

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