scholarly journals Immunogenic T cell epitopes of SARS-CoV-2 are recognized by circulating memory and naïve CD8 T cells of unexposed individuals

EBioMedicine ◽  
2021 ◽  
Vol 72 ◽  
pp. 103610
Author(s):  
Isaac Quiros-Fernandez ◽  
Mansour Poorebrahim ◽  
Elham Fakhr ◽  
Angel Cid-Arregui
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Epitopes

Prediction of Prophylactic Peptide Vaccine Candidates for Human Papillomavirus (HPV): An Immunoinformatics and Reverse Vaccinology Approach

2020 ◽  
Vol 17 ◽  
Author(s):  
Mehreen Ismail ◽  
Zureesha Sajid ◽  
Amjad Ali ◽  
Xiaogang Wu ◽  
Syed Aun Muhammad ◽  
...  
Keyword(s):  
T Cells ◽  
Human Papillomavirus ◽  
T Cell ◽  
Binding Affinity ◽  
Cd8 T Cells ◽  
Reverse Vaccinology ◽  
Host Immune System ◽  
T Cell Epitopes ◽  
Multiple Alleles ◽  
Vaccine Candidates

Background: Human Papillomavirus (HPV) is responsible for substantial morbidity and mortality worldwide. We predicted immunogenic promiscuous monovalent and polyvalent T-cell epitopes from the polyprotein of the Human Papillomavirus (HPV) using a range of bioinformatics tools and servers. Methods: We used immunoinformatics and reverse vaccinology-based approaches to design prophylactic peptides by antigenicity analysis, Tcell epitopes prediction, proteasomal and conservancy evaluation, host-pathogen protein interactions, and in silico binding affinity analysis. Results: We found two early proteins (E2 and E6) and two late proteins (L1 and L2) of HPV as potential vaccine candidates. Of these proteins (E2, E6, L1 & L2), 2-epitopes of each candidate protein for multiple alleles of MHC class I and II bearing significant binding affinity (>-6.0 kcal/mole). These potential epitopes for CD4+ and CD8+ T-cells were also linked to design polyvalent construct using GPGPG linkers. Cholera toxin B and mycobacterial heparin-binding hemagglutinin adjuvant with a molecular weight of 12.5 and 18.5 kDa were used for epitopes of CD4+ and CD8+ T-cells respectively. The molecular docking indicated the optimum binding affinity of HPV peptides with MHC molecules. This interaction showed that our predicted vaccine candidates are suitable to trigger the host immune system to prevent HPV infections. Conclusion: The predicted conserved T-cell epitopes would contribute to the imminent design of HPV vaccine candidates, which will be able to induce a broad range of immune-responses in a heterogeneous HLA population.

scholarly journals Protection against Vaccinia Virus Challenge by CD8 Memory T Cells Resolved by Molecular Mimicry

2006 ◽  
Vol 81 (2) ◽  
pp. 934-944 ◽  
Author(s):  
Markus Cornberg ◽  
Brian S. Sheridan ◽  
Frances M. Saccoccio ◽  
Michael A. Brehm ◽  
Liisa K. Selin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Vaccinia Virus ◽  
Cd8 T Cells ◽  
Protective Immunity ◽  
Molecular Mimicry ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Epitopes ◽  
Cell Responses

ABSTRACT Live vaccinia virus (VV) vaccination has been highly successful in eradicating smallpox. However, the mechanisms of immunity involved in mediating this protective effect are still poorly understood, and the roles of CD8 T-cell responses in primary and secondary VV infections are not clearly identified. By applying the concept of molecular mimicry to identify potential CD8 T-cell epitopes that stimulate cross-reactive T cells specific to lymphocytic choriomeningitis virus (LCMV) and VV, we identified after screening only 115 peptides two VV-specific immunogenic epitopes that mediated protective immunity against VV. An immunodominant epitope, VV-e7r130, did not generate cross-reactive T-cell responses to LCMV, and a subdominant epitope, VV-a11r198, did generate cross-reactive responses to LCMV. Infection with VV induced strong epitope-specific responses which were stable into long-term memory and peaked at the time virus was cleared, consistent with CD8 T cells assisting in the control of VV. Two different approaches, direct adoptive transfer of VV-e7r-specific CD8 T cells and prior immunization with a VV-e7r-expressing ubiquitinated minigene, demonstrated that memory CD8 T cells alone could play a significant role in protective immunity against VV. These studies suggest that exploiting cross-reactive responses between viruses may be a useful tool to complement existing technology in predicting immunogenic epitopes to large viruses, such as VV, leading to a better understanding of the role CD8 T cells play during these viral infections.

CD8+ T-Cell Responses in Hepatitis B and C: The (HLA-) A, B, and C of Hepatitis B and C

2016 ◽  
Vol 34 (4) ◽  
pp. 396-409 ◽  
Author(s):  
Katja Nitschke ◽  
Hendrik Luxenburger ◽  
Muthamia M. Kiraithe ◽  
Robert Thimme ◽  
Christoph Neumann-Haefelin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hepatitis B ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Acute Infection ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Hcv Infection ◽  
T Cell Epitopes

Approximately 500 million people are chronically infected with the hepatitis B virus (HBV) or hepatitis C virus (HCV) worldwide and are thus at high risk of progressive liver disease, leading to liver fibrosis, cirrhosis and ultimately hepatocellular cancer. Virus-specific CD8+ T-cells play a major role in viral clearance in >90% of adult patients who clear HBV and in approximately 30% of patients who clear HCV in acute infection. However, several mechanisms contribute to the failure of the adaptive CD8+ T-cell response in those patients who progress to chronic infection. These include viral mutations leading to escape from the CD8+ T-cell response as well as exhaustion and dysfunction of virus-specific CD8+ T-cells. Antiviral efficacy of the virus-specific CD8+ T-cell response also strongly depends on its restriction by specific human leukocyte antigens (HLA) class I alleles. Our review will summarize the role of HLA-A, B and C-restricted CD8+ T-cells in HBV and HCV infection. Due to the current lack of a comprehensive database of HBV- and HCV-specific CD8+ T-cell epitopes, we also provide a summary of the repertoire of currently well-described HBV- and HCV-specific CD8+ T-cell epitopes. A better understanding of the factors that contribute to the success or failure of virus-specific CD8+ T-cells may help to develop new therapeutic options for HBV eradication in patients with chronic HBV infection (therapeutic vaccination and/or immunomodulation) as well as a prophylactic vaccine against HCV infection.

scholarly journals HLA Class I-T Cell Epitopes from trans-Sialidase Proteins Reveal Functionally Distinct Subsets of CD8+ T Cells in Chronic Chagas Disease

2008 ◽  
Vol 2 (9) ◽  
pp. e288 ◽  
Author(s):  
María G. Alvarez ◽  
Miriam Postan ◽  
D. Brent Weatherly ◽  
María C. Albareda ◽  
John Sidney ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chagas Disease ◽  
Cd8 T Cells ◽  
Hla Class I ◽  
Class I ◽  
T Cell Epitopes ◽  
Chronic Chagas Disease

scholarly journals 21-Hydroxylase-Specific CD8+ T Cells in Autoimmune Addison’s Disease Are Restricted by HLA-A2 and HLA-C7 Molecules

2021 ◽  
Vol 12 ◽  
Author(s):  
Alexander Hellesen ◽  
Sigrid Aslaksen ◽  
Lars Breivik ◽  
Ellen Christine Røyrvik ◽  
Øyvind Bruserud ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Addison’S Disease ◽  
Cd8 T Cell ◽  
Addison's Disease ◽  
T Cell Epitopes ◽  
Biochemical Assays ◽  
Dominant Epitope

ObjectivesCD8+ T cells targeting 21-hydroxylase (21OH) are presumed to play a central role in the destruction of adrenocortical cells in autoimmune Addison’s disease (AAD). Earlier reports have suggested two immunodominant CD8+ T cell epitopes within 21OH: LLNATIAEV (21OH342-350), restricted by HLA-A2, and EPLARLEL (21OH431-438), restricted by HLA-B8. We aimed to characterize polyclonal CD8+ T cell responses to the proposed epitopes in a larger patient cohort with AAD.MethodsRecombinant fluorescent HLA-peptide multimer reagents were used to quantify antigen-specific CD8+ T cells by flow cytometry. Interferon-gamma (IFNγ) Elispot and biochemical assays were used to functionally investigate the 21OH-specific T cells, and to map the exactly defined epitopes of 21OH.ResultsWe found a significantly higher frequency of HLA-A2 restricted LLNATIAEV-specific cells in patients with AAD than in controls. These cells could also be expanded in vitro in an antigen specific manner and displayed a robust antigen-specific IFNγ production. In contrast, only negligible frequencies of EPLARLEL-specific T cells were detected in both patients and controls with limited IFNγ response. However, significant IFNγ production was observed in response to a longer peptide encompassing EPLARLEL, 21OH430-447, suggesting alternative dominant epitopes. Accordingly, we discovered that the slightly offset ARLELFVVL (21OH434-442) peptide is a novel dominant epitope restricted by HLA-C7 and not by HLA-B8 as initially postulated.ConclusionWe have identified two dominant 21OH epitopes targeted by CD8+ T cells in AAD, restricted by HLA-A2 and HLA-C7, respectively. To our knowledge, this is the first HLA-C7 restricted epitope described for an autoimmune disease.

R-DOTAP (Versamune): A novel enantiospecific cationic lipid nanoparticle that induces CD4 and CD8 cellular immune responses to whole protein and tumor-specific peptide antigens.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15211-e15211
Author(s):  
Lauren Virginia Wood ◽  
Siva K Gandhapudi ◽  
Karuna Sundarapandiyan ◽  
Frank K Bedu-Addo ◽  
Gregory Conn ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cationic Lipid ◽  
Cd8 T Cell ◽  
Lipid Nanoparticles ◽  
Type I ◽  
T Cell Epitopes ◽  
Ifn Γ

e15211 Background: Immunotherapy approaches are limited in their ability to induce antigen-specific CD8+ T cells in vivo able to recognize and kill tumor cells. We developed a novel immunotherapy approach using enantiomerically pure, R-DOTAP cationic lipid nanoparticles and tumor-derived T cell antigens, and previously demonstrated that R-DOTAP formulations efficiently prime cytotoxic T cells through enhanced cross presentation and induction of type I interferons.[1] A phase I clinical trial of a R-DOTAP HPV16 peptide formulation confirmed induction of strong in vivo HPV-specific CD8+ cytolytic T-cells without associated systemic toxicities. In this study, we assessed R-DOTAP nanoparticle formulations containing whole protein (ovalbumin) or long multi-epitope peptides from the tumor antigen TARP (T-cell alternate reading frame protein): a 58-residue protein overexpressed in prostate and breast cancers, documented to be immunogenic in humans. Methods: R-DOTAP formulations were prepared containing ovalbumin (OVA) or TARP peptides. C57BL/6K mice were immunized with 10 μg/mouse of OVA plus R-DOTAP, CFA or sucrose on Days 0, 15 and 30. OVA-specific cellular and humoral responses following vaccination were assessed by measuring splenic CD4 and CD8 T cell IFN-γ production and circulating OVA-specific antibodies in serum. HLA-A2 transgenic mice (AAD mice) were vaccinated with long, multi-epitope TARP peptides delivered as an R-DOTAP admixture or with CFA or sucrose on Days 0 and 7. Antigen-specific T cell responses were measured by IFN-γ ELISpot assay. Results: OVA R-DOTAP formulations induced strong antigen-specific effector CD4 and CD8 immune and memory responses detected 7 and 30 days, respectively, following vaccination as well as OVA-specific antibody responses. In TARP peptide vaccinated mice, R-DOTAP formulations were able to present multiple CD8 T cell epitopes and stimulate responses that were superior to CFA. Conclusions: Our results suggest that R-DOTAP is a versatile immune activating therapy that can be formulated with long, multi-epitope tumor-derived peptides or whole proteins. R-DOTAP formulations induce quantitatively robust antigen-specific CD4 and CD8 T cells in vivo compared to well-established immune stimulants. Reference: 1.Gandhapudi SK, Ward M, Bush JP et al. Antigen Priming with Enantiospecific Cationic Lipid Nanoparticles Induces Potent Antitumor CTL Responses through Novel Induction of a Type I IFN Response. J Immunol 2019;202:3524-3536

scholarly journals DNA vaccination with T-cell epitopes encoded within Ab molecules induces high-avidity anti-tumor CD8+T cells

2010 ◽  
Vol 40 (3) ◽  
pp. 899-910 ◽  
Author(s):  
Victoria A. Pudney ◽  
Rachael L. Metheringham ◽  
Barbara Gunn ◽  
Ian Spendlove ◽  
Judith M. Ramage ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Dna Vaccination ◽  
High Avidity ◽  
T Cell Epitopes

scholarly journals Conditional Immune Escape during Chronic Simian Immunodeficiency Virus Infection

2015 ◽  
Vol 90 (1) ◽  
pp. 545-552 ◽  
Author(s):  
Dane D. Gellerup ◽  
Alexis J. Balgeman ◽  
Chase W. Nelson ◽  
Adam J. Ericsen ◽  
Matthew Scarlotta ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Escape ◽  
Cd8 T Cell ◽  
T Cell Epitopes ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Siv Infection ◽  
Mhc Alleles

ABSTRACT Anti-HIV CD8 T cells included in therapeutic treatments will need to target epitopes that do not accumulate escape mutations. Identifying the epitopes that do not accumulate variants but retain immunogenicity depends on both host major histocompatibility complex (MHC) genetics and the likelihood for an epitope to tolerate variation. We previously found that immune escape during acute SIV infection is conditional; the accumulation of mutations in T cell epitopes is limited, and the rate of accumulation depends on the number of epitopes being targeted. We have now tested the hypothesis that conditional immune escape extends into chronic SIV infection and that epitopes with a preserved wild-type sequence have the potential to elicit epitope-specific CD8 T cells. We deep sequenced simian immunodeficiency virus (SIV) from Mauritian cynomolgus macaques (MCMs) that were homozygous and heterozygous for the M3 MHC haplotype and had been infected with SIV for about 1 year. When interrogating variation within individual epitopes restricted by M3 MHC alleles, we found three categories of epitopes, which we called categories A, B, and C. Category B epitopes readily accumulated variants in M3-homozygous MCMs, but this was less common in M3-heterozygous MCMs. We then determined that chronic CD8 T cells specific for these epitopes were more likely preserved in the M3-heterozygous MCMs than M3-homozygous MCMs. We provide evidence that epitopes known to escape from chronic CD8 T cell responses in animals that are homozygous for a set of MHC alleles are preserved and retain immunogenicity in a host that is heterozygous for the same MHC alleles. IMPORTANCE Anti-HIV CD8 T cells that are part of therapeutic treatments will need to target epitopes that do not accumulate escape mutations. Defining these epitope sequences is a necessary precursor to designing approaches that enhance the functionality of CD8 T cells with the potential to control virus replication during chronic infection or after reactivation of latent virus. Using MHC-homozygous and -heterozygous Mauritian cynomolgus macaques, we have now obtained evidence that epitopes known to escape from chronic CD8 T cell responses in animals that are MHC homozygous are preserved and retain immunogenicity in a host that is heterozygous for the same MHC alleles. Importantly, our findings support the conditional immune escape hypothesis, such that the potential to present a greater number of CD8 T cell epitopes within a single animal can delay immune escape in targeted epitopes. As a result, certain epitope sequences can retain immunogenicity into chronic infection.

New SARS-CoV-2 lineages could evade CD8+ T-cells response

2021 ◽  
Author(s):  
Marco Antonio M. Pretti ◽  
Rômulo G. Galvani ◽  
Alessandro S Farias ◽  
Mariana Boroni
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Reference Sequence ◽  
T Cell Epitopes ◽  
Antibody Recognition ◽  
Cell Responses ◽  
The Uk

AbstractBackgroundMany SARS-CoV-2 variants of concern have emerged since the Covid-19 outburst, notably the lineages detected in the UK, South Africa, and Brazil. Their increased transmissibility and higher viral load put them in the spotlight. Much has been investigated on the ability of those new variants to evade antibody recognition. However, not enough attention has been given to pre-existing and induced SARS-CoV-2-specific CD8+ T cell responses during the natural course of infection by new lineages.MethodsIn this work, we investigated the SARS-CoV-2-specific CD8+ T cell epitopes from the main variants of concern and the potential of associated mutations to trigger or hinder CD8+ T-cells response. We also estimated the population’s coverage of these different lineages, considering peptide binding predictions to class I HLA alleles from 29 countries to investigate differences in the fraction of individuals expected to respond to a given epitope set from new and previous lineages.ResultsWe observed a lower populational coverage for 20B/S.484K (P2 lineage) in contrast to an increased coverage found for 20H/501Y.V2 (B.1.351 Lineage) and 20J/501Y.V3 (P1 lineage) compared to a reference lineage. Moreover, mutations such as Spike N501Y and Nucleocapsid T205I were predicted to have an overall higher affinity through HLA-I than the reference sequence.ConclusionsIn summary, the data in this work provided evidence for the existence of potentially immunogenic and conserved epitopes across new SARS-CoV-2 variants, but also highlights the reduced populational’s coverage for the Brazilian lineage P.1, suggesting its potential to evade from CD8+ T-cell responses. Our results also may guide efforts to characterize and validate relevant peptides to trigger CD8+ T-cell responses, and design new universal T-cell-inducing vaccine candidates that minimize detrimental effects of viral diversification and at the same time induce responses to a broad human population.

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