scholarly journals Structural modeling and conserved epitopes prediction against SARS-COV-2 structural proteins for vaccine development

Author(s):  
Muhammad Tahir ul Qamar ◽  
Farah Shahid ◽  
Usman Ali Ashfaq ◽  
Sidra Aslam ◽  
Israr Fatima ◽  
...  

Abstract Background: Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Corona virus 2 (SARS-COV-2) was first diagnosed in December 2019, Wuhan, China. Little is known about this new virus and it has the potential to cause severe illness and pneumonia in some people, therefore the development of an effective vaccine is highly desired.Methods: Immunoinformatics and statistical approaches were used in this study to forecast B- and T- cell epitopes for the SARS-COV-2 structural proteins (Surface glycoprotein, Envelope protein, and Membrane glycoprotein) that may play a key role in eliciting immune response against COVID-19. Different types of B cell epitopes (linear as well as discontinuous) and T cell (MHC class I and MHC class II) were determined. Moreover, their antigenicity and allergenicity were also estimated.Results: The antigenic B-cell epitopes exposed to the outer surface were screened out and 23 linear B cell epitopes were selected. “SPTKLNDLCFTNVY” had the highest antigenicity score among B cell epitopes. The T-cell epitopes bound to multiple alleles, antigenic, non-allergen, non-toxic, and conserved in the protein sequence were shortlisted. In total, 16 epitopes (9 from MHC class I and 7 from MHC class II) were selected. Among the T-cell epitopes, MHC class I (IPFAMQMAYRFN) and MHC class II (VTLACFVLAAVYRIN) were classified as strongly antigenic. Digestion analysis verified the safety and stability of the peptides predicted during this study. Furthermore, docking analyses of predicted peptides showed significant interactions with the HLA-B7 allele.Conclusion: The putative antigen epitopes identified in this study may serve as vaccine candidates and can help to eliminate/control growing health threat of COVID-19.

Author(s):  
Jesvin Bency B. ◽  
Mary Helen P. A.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative viral strain for the contagious pandemic respiratory illness in humans which is a public health emergency of international concern. There is a desperate need for vaccines and antiviral strategies to combat the rapid spread of SARS-CoV-2 infection.Methods: The present study based on computational methods has identified novel conserved cytotoxic T-lymphocyte epitopes as well as linear and discontinuous B-cell epitopes on the SARS-CoV-2 spike (S) protein. The predicted MHC class I and class II binding peptides were further checked for their antigenic scores, allergenicity, toxicity, digesting enzymes and mutation.Results: A total of fourteen linear B-cell epitopes where GQSKRVDFC displayed the highest antigenicity-score and sixteen highly antigenic 100% conserved T-cell epitopes including the most potential vaccine candidates MHC class-I peptide KIADYNYKL and MHC class-II peptide VVFLHVTYV were identified. Furthermore, the potential peptide QGFSALEPL with high antigenicity score attached to larger number of human leukocyte antigen alleles. Docking analyses of the allele HLA-B*5201 predicted to be immunogenic to several of the selected epitopes revealed that the peptides engaged in strong binding with the HLA-B*5201 allele.Conclusions: Collectively, this research provides novel candidates for epitope-based peptide vaccine design against SARS-CoV-2 infection.


2020 ◽  
Author(s):  
Yengkhom Damayanti Devi ◽  
Himanshu Ballav Goswami ◽  
Sushmita Konwar ◽  
Chandrima Doley ◽  
Anutee Dolley ◽  
...  

Abstract Researchers around the world are developing more than 145 vaccines (DNA/mRNA/whole-virus/viral-vector/protein-based/repurposed vaccine) against the SARS-CoV-2 and 21 vaccines are in human trials. However, a limited information is available about which SARS-CoV-2 proteins are recognized by human B- and T-cell immune responses. Using a comprehensive computational prediction algorithm and stringent selection criteria, we have predicted and identified potent B- and T-cell epitopes in the structural proteins of SARS-CoV and SARS-CoV-2. The amino acid residues spanning the predicted linear B-cell epitope in the RBD of S protein (370-NSASFSTFKCYGVSPTKLNDLCFTNV-395) have recently been identified for interaction with the CR3022, a previously described neutralizing antibody known to neutralize SARS-CoV-2 through binding to the RBD of the S protein. Intriguingly, most of the amino acid residues spanning the predicted B-cell epitope (aa 331-NITNLCPFGEVFNATRFASVYAWNRK-356, 403-RGDEVRQIAPGQTGKIADYNYKLPD-427 and aa 437- NSNNLDSKVGGNYNYLYRLFRKSNL-461) of the S protein have been experimentally verified to interact with the cross-neutralizing mAbs (S309 and CB6) in an ACE2 receptor-S protein interaction independent-manner. In addition, we found that computationally predicted epitope of S protein (370-395) is likely to function as both linear B-cell and MHC class II epitope. Similarly, 403-27 and 437-461 peptides of S protein were predicted as linear B cell and MHC class I epitope while, 177-196 and 1253-1273 peptides of S protein were predicted as linear and conformational B cell epitope. We found MHC class I epitope 316-GMSRIGMEV-324 predicted as high affinity epitope (HLA-A*02:03, HLA-A*02:01, HLA-A*02:06) common to N protein of both SARS-CoV-2 and SARS-CoV (N317-325) was previously shown to induce interferon-gamma (IFN-γ) in PBMCs of SARS-recovered patients. Interestingly, two MHC class I epitopes, 1041-GVVFLHVTY-1049 (HLA-A*11:01, HLA-A*68:01, HLA-A*03:01) and 1202-FIAGLIAIV-1210 (HLA-A*02:06, HLA-A*68:02) derived from SARS-CoV S protein with epitope conservancy between 85 to 100% with S protein of SARS-CoV-2 was experimentally verified using PBMCs derived from SARS-CoV patients. We observed that HLA-A*02:01, HLA-A*02:03, HLA-A*02:06, HLA-A*11:01, HLA-A*30:01, HLA-A*68:01, HLA-A*68:02, HLA-B*15:01 and HLA-B*35:01 have been predicted to bind to the maximum number of MHC class I epitope (based on the criterion of allele predicted to bind more than 30 epitopes) of S protein of SARS-CoV-2. Similarly, we observed that HLA-A*02:06, HLA-A*30:01, HLA-A*30:02, HLA-A*31:01, HLA-A*32:01, HLA-A*68:01, HLA-A*68:02, HLA-B*15:01 and HLA-B*35:01 are predicted to bind to the maximum number of MHC class I epitope of N protein of SARS-CoV-2. We found that HLA-DRB1*04:01, HLA-DRB1*04:05, HLA-DRB1*13:02, HLA-DRB1*15:01, HLA-DRB3*01:01, HLA-DRB3*02:02, HLA-DRB4*01:01, HLA-DRB5*01:01, HLA-DQA1*04:01, DQB1*04:02, HLA-DPA1*02:01, DPB1*01:01, HLA-DPA1*01:03, DPB1*02:01, HLA-DPA1*01:03, DPB1*04:01, HLA-DPA1*03:01, DPB1*04:02, HLA-DPA1*02:01, DPB1*05:01, HLA-DPA1*02:01, and DPB1*14:01 are predicted to bind to the maximum number of MHC class II epitope of S protein of SARS-CoV-2. Alleles such as HLA-DRB1*04:01, HLA-DRB1*07:01, HLA-DRB1*08:02, HLA-DRB1*09:01, HLA-DRB1*11:01, HLA-DRB1*13:02, HLA-DRB3*02:02, HLA-DRB5*01:01, HLA-DQA1*01:02, DQB1*06:02, DPB1*05:01 and HLA-DPA1*02:01 are found to interact with the maximum number of MHC class II epitope of N protein of SARS-CoV-2. Using the IEDB tool we found the occurrence of HLA alleles with population coverage of around 99% throughout the world. The findings of computational predictions of mega-pool of B- and T-cell epitopes identified in the four main structural proteins of SARS-CoV-2 provides a platform for future experimental validations and the results of present works support the use of RBD or the full-length S and N proteins in an effort towards designing of recombinant protein-based vaccine and a serological diagnostic assay for SARS-CoV-2.


2020 ◽  
Author(s):  
Stephen N. Crooke ◽  
Inna G. Ovsyannikova ◽  
Richard B. Kennedy ◽  
Gregory A. Poland

AbstractA novel coronavirus (SARS-CoV-2) emerged from China in late 2019 and rapidly spread across the globe, infecting millions of people and generating societal disruption on a level not seen since the 1918 influenza pandemic. A safe and effective vaccine is desperately needed to prevent the continued spread of SARS-CoV-2; yet, rational vaccine design efforts are currently hampered by the lack of knowledge regarding viral epitopes targeted during an immune response, and the need for more in-depth knowledge on betacoronavirus immunology. To that end, we developed a computational workflow using a series of open-source algorithms and webtools to analyze the proteome of SARS-CoV-2 and identify putative T cell and B cell epitopes. Using increasingly stringent selection criteria to select peptides with significant HLA promiscuity and predicted antigenicity, we identified 41 potential T cell epitopes (5 HLA class I, 36 HLA class II) and 6 potential B cell epitopes, respectively. Docking analysis and binding predictions demonstrated enrichment for peptide binding to HLA-B (class I) and HLA-DRB1 (class II) molecules. Overlays of predicted B cell epitopes with the structure of the viral spike (S) glycoprotein revealed that 4 of 6 epitopes were located in the receptor-binding domain of the S protein. To our knowledge, this is the first study to comprehensively analyze all 10 (structural, non-structural and accessory) proteins from SARS-CoV-2 using predictive algorithms to identify potential targets for vaccine development.Significance StatementThe novel coronavirus SARS-CoV-2 recently emerged from China, rapidly spreading and ushering in a global pandemic. Despite intensive research efforts, our knowledge of SARS-CoV-2 immunology and the proteins targeted by the immune response remains relatively limited, making it difficult to rationally design candidate vaccines. We employed a suite of bioinformatic tools, computational algorithms, and structural modeling to comprehensively analyze the entire SARS-CoV-2 proteome for potential T cell and B cell epitopes. Utilizing a set of stringent selection criteria to filter peptide epitopes, we identified 41 T cell epitopes (5 HLA class I, 36 HLA class II) and 6 B cell epitopes that could serve as promising targets for peptide-based vaccine development against this emerging global pathogen.


2020 ◽  
Author(s):  
Kathrin Balz ◽  
Meng Chen ◽  
Abhinav Kaushik ◽  
Franz Cemic ◽  
Vanessa Heger ◽  
...  

Abstract The outbreak of the new Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a public health emergency. Asthma does not represent a risk factor for COVID-19 in several published cohorts. We hypothesized that the SARS-CoV-2 proteome contains T cell epitopes, which are potentially cross-reactive to allergen epitopes. We aimed at identifying homologous peptide sequences by means of two distinct complementary bioinformatics approaches. Pipeline 1 included prediction of MHC Class I and Class II epitopes contained in the SARS-CoV-2 proteome and allergens along with alignment and elaborate ranking approaches. Pipeline 2 involved alignment of SARS-CoV-2 overlapping peptides with known allergen-derived T cell epitopes. Our results indicate a large number of MHC Class I epitope pairs including known as well as de novo predicted allergen T cell epitopes with high probability for cross-reactivity. Allergen sources, such as Aspergillus fumigatus, Phleum pratense and Dermatophagoides species are of particular interest due to their association with multiple cross-reactive candidate peptides, independently of the applied bioinformatic approach. In contrast, peptides derived from food allergens, as well as MHC class II epitopes did not achieve high in silico ranking and were therefore not further investigated. Our findings warrant further experimental confirmation along with examination of the functional importance of such cross-reactive responses.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kathrin Balz ◽  
Abhinav Kaushik ◽  
Meng Chen ◽  
Franz Cemic ◽  
Vanessa Heger ◽  
...  

AbstractThe outbreak of the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a public health emergency. Asthma does not represent a risk factor for COVID-19 in several published cohorts. We hypothesized that the SARS-CoV-2 proteome contains T cell epitopes, which are potentially cross-reactive to allergen epitopes. We aimed at identifying homologous peptide sequences by means of two distinct complementary bioinformatics approaches. Pipeline 1 included prediction of MHC Class I and Class II epitopes contained in the SARS-CoV-2 proteome and allergens along with alignment and elaborate ranking approaches. Pipeline 2 involved alignment of SARS-CoV-2 overlapping peptides with known allergen-derived T cell epitopes. Our results indicate a large number of MHC Class I epitope pairs including known as well as de novo predicted allergen T cell epitopes with high probability for cross-reactivity. Allergen sources, such as Aspergillus fumigatus, Phleum pratense and Dermatophagoides species are of particular interest due to their association with multiple cross-reactive candidate peptides, independently of the applied bioinformatic approach. In contrast, peptides derived from food allergens, as well as MHC class II epitopes did not achieve high in silico ranking and were therefore not further investigated. Our findings warrant further experimental confirmation along with examination of the functional importance of such cross-reactive responses.


Immunology ◽  
2011 ◽  
Vol 132 (4) ◽  
pp. 482-491 ◽  
Author(s):  
Mingjun Wang ◽  
Sheila T. Tang ◽  
Anette Stryhn ◽  
Sune Justesen ◽  
Mette V. Larsen ◽  
...  

2010 ◽  
Vol 37 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Gerd Meyer zu Hörste ◽  
Holger Heidenreich ◽  
Anne K. Mausberg ◽  
Helmar C. Lehmann ◽  
Anneloor L.M.A. ten Asbroek ◽  
...  

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Muhammad Tahir ul Qamar ◽  
Saman Saleem ◽  
Usman Ali Ashfaq ◽  
Amna Bari ◽  
Farooq Anwar ◽  
...  

Abstract Background Middle East Respiratory Syndrome Coronavirus (MERS-COV) is the main cause of lung and kidney infections in developing countries such as Saudi Arabia and South Korea. This infectious single-stranded, positive (+) sense RNA virus enters the host by binding to dipeptidyl-peptide receptors. Since no vaccine is yet available for MERS-COV, rapid case identification, isolation, and infection prevention strategies must be used to combat the spreading of MERS-COV infection. Additionally, there is a desperate need for vaccines and antiviral strategies. Methods The present study used immuno-informatics and computational approaches to identify conserved B- and T cell epitopes for the MERS-COV spike (S) protein that may perform a significant role in eliciting the resistance response to MERS-COV infection. Results Many conserved cytotoxic T-lymphocyte epitopes and discontinuous and linear B-cell epitopes were predicted for the MERS-COV S protein, and their antigenicity and interactions with the human leukocyte antigen (HLA) B7 allele were estimated. Among B-cell epitopes, QLQMGFGITVQYGT displayed the highest antigenicity-score, and was immensely immunogenic. Among T-cell epitopes, MHC class-I peptide YKLQPLTFL and MHC class-II peptide YCILEPRSG were identified as highly antigenic. Furthermore, docking analyses revealed that the predicted peptides engaged in strong bonding with the HLA-B7 allele. Conclusion The present study identified several MERS-COV S protein epitopes that are conserved among various isolates from different countries. The putative antigenic epitopes may prove effective as novel vaccines for eradication and combating of MERS-COV infection.


2016 ◽  
Vol 44 ◽  
pp. 182-189 ◽  
Author(s):  
Iti Saraav ◽  
Kirti Pandey ◽  
Monika Sharma ◽  
Swati Singh ◽  
Prasun Dutta ◽  
...  

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1330-1330
Author(s):  
Sanja Stevanovic ◽  
Bart Nijmeijer ◽  
Marianke LJ Van Schie ◽  
Roelof Willemze ◽  
Marieke Griffioen ◽  
...  

Abstract Abstract 1330 Poster Board I-352 Immunodeficient mice inoculated with human leukemia can be used as a model to investigate Graft-versus-Leukemia (GvL) effects of donor lymphocyte infusions (DLIs). In addition to GvL reactivity, treatment with DLI induces xenogeneic Graft-versus-Host Disease (GvHD) in mice, characterized by pancytopenia and weight loss. In patients treated with DLI for relapsed or residual leukemia after allogeneic stem cell transplantation, immune responses against non-leukemic cells may also cause GvHD. It has been suggested that GvL reactivity and GvHD, which co-develop in vivo, can be separated and that distinct T cells exist with the specific capacity to mediate GvL reactivity or GvHD. Since adoptive T cell transfer models that allow analysis of separation of GvL and GvHD are rare, we aimed to establish whether GvL reactivity and xenogeneic GvHD could be separated using our model of human leukemia-engrafted NOD/scid mouse after treatment with human donor T cells. In this study, non-conditioned NOD/scid mice engrafted with primary human acute lymphoblastic leukemic cells were treated with CD3+ DLI. Established tumors were effectively eliminated by emerging human T cells, but also induced xenogeneic GvHD. Flowcytometric analysis demonstrated that the majority of emerging CD8+ and CD4+ T cells were activated (HLA-DR+) and expressed an effector memory phenotype (CD45RA-CD45RO+CCR7-). To investigate whether GvL reactivity and xenogeneic GvHD were mediated by the same T cells showing reactivity against both human leukemic and murine cells, or displaying distinct reactivity against human leukemic and murine cells, we clonally isolated and characterized the T cells during the GvL response and xenogeneic GvHD. T cell clones were analyzed for reactivity against primary human leukemic cells and primary NOD/scid hematopoietic (BM and spleen cells) and non-hematopoietic (skin fibroblasts) cells in IFN-g ELISA. Isolated CD8+ and CD4+ T cell clones were shown to recognize either human leukemic or murine cells, indicating that GvL response and xenogeneic GvHD were mediated by different human T cells. Flowcytometric analysis demonstrated that all BM and spleen cells expressed MHC class I, whereas only 1-3 % of the cells were MHC class II +. Primary skin fibroblasts displayed low MHC class I and completely lacked MHC class II expression. Xeno-reactive CD8+ T cell clones were shown to recognize all MHC class I + target cells and xeno-reactive CD4+ T cells clones displayed reactivity only against MHC class II + target cells. To determine the MHC restriction of xeno-reactive T cell clones, NOD/scid bone marrow (BM) derived dendritic cells (DC) expressing high levels of murine MHC class I and class II were tested for T cell recognition in the presence or absence of murine MHC class I and class II monoclonal antibodies in IFN-g ELISA. Xeno-reactive CD8+ T cell clones were shown to be MHC class I (H-2Kd or H-2Db) restricted, whereas xeno-reactive CD4+ T cell clones were MHC class II (I-Ag7) restricted, indicating that xeno-reactivity reflects genuine human T cell response directed against allo-antigens present on murine cells. Despite production of high levels of IFN-gamma, xeno-reactive CD8+ and CD4+ T cell clones failed to exert cytolytic activity against murine DC, as determined in a 51Cr-release cytotoxicity assay. Absence of cytolysis by CD8+ T cell clones, which are generally considered as potent effector cells, may be explained by low avidity interaction between human T cells and murine DC, since flowcytometric analysis revealed sub-optimal activation of T cells as measured by CD137 expression and T cell receptor downregulation upon co-culture with murine DC, and therefore these results indicate that xenogeneic GvHD in this model is likely to be mediated by cytokines. In conclusion, in leukemia-engrafted NOD/scid mice treated with CD3+ DLI, we show that GvL reactivity and xenogeneic GvHD are mediated by separate human T cells with distinct specificities. All xeno-reactive T cell clones showed genuine recognition of MHC class I or class II associated allo-antigens on murine cells similar as GvHD-inducing human T cells. These data suggest that our NOD/scid mouse model of human acute leukemia may be valuable for studying the effectiveness and specificity of selectively enriched or depleted T cells for adoptive immunotherapy. Disclosures: No relevant conflicts of interest to declare.


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