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1.
Hum Immunol ; 83(1): 1-9, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1719801

ABSTRACT

The class I and class II Human Leucocyte Antigens (HLA) are an integral part of the host adaptive immune system against viral infections. The characterization of HLA allele frequency in the population can play an important role in determining whether HLA antigens contribute to viral susceptibility. In this regard, global efforts are currently underway to study possible correlations between HLA alleles with the occurrence and severity of SARS-CoV-2 infection. Specifically, this study examined the possible association between specific HLA alleles and susceptibility to SARS-CoV-2 in a population from the United Arab Emirates (UAE). The frequencies of HLA class I (HLA-A, -B, and -C) and HLA class II alleles (HLA-DRB1 and -DQB1); defined using Next Generation Sequencing (NGS); from 115 UAE nationals with mild, moderate, and severe SARS-CoV-2 infection are presented here. HLA alleles and supertypes were compared between hospitalized and non-hospitalized subjects. Statistical significance was observed between certain HLA alleles and supertypes and the severity of the infection. Specifically, alleles HLA-B*51:01 and HLA-A*26:01 showed a negative association (suggestive of protection), whilst genotypes HLA-A*03:01, HLA-DRB1*15:01, and supertype B44 showed a positive association (suggestive of predisposition) to COVID-19 severity. The results support the potential use of HLA testing to differentiate between patients who require specific clinical management strategies.


Subject(s)
COVID-19/genetics , HLA Antigens/genetics , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/diagnosis , COVID-19/immunology , COVID-19/virology , Female , Gene Frequency , Genetic Predisposition to Disease , HLA Antigens/immunology , Haplotypes , Host-Pathogen Interactions , Humans , Male , Middle Aged , Protective Factors , Risk Assessment , Risk Factors , SARS-CoV-2/pathogenicity , Severity of Illness Index , United Arab Emirates , Young Adult
2.
Int J Mol Sci ; 23(5)2022 Feb 28.
Article in English | MEDLINE | ID: covidwho-1715409

ABSTRACT

We propose a new hypothesis that explains the maintenance and evolution of MHC polymorphism. It is based on two phenomena: the constitution of the repertoire of naive T lymphocytes and the evolution of the pathogen and its impact on the immune memory of T lymphocytes. Concerning the latter, pathogen evolution will have a different impact on reinfection depending on the MHC allomorph. If a mutation occurs in a given region, in the case of MHC allotypes, which do not recognize the peptide in this region, the mutation will have no impact on the memory repertoire. In the case where the MHC allomorph binds to the ancestral peptides and not to the mutated peptide, that individual will have a higher chance of being reinfected. This difference in fitness will lead to a variation of the allele frequency in the next generation. Data from the SARS-CoV-2 pandemic already support a significant part of this hypothesis and following up on these data may enable it to be confirmed. This hypothesis could explain why some individuals after vaccination respond less well than others to variants and leads to predict the probability of reinfection after a first infection depending upon the variant and the HLA allomorph.


Subject(s)
COVID-19/immunology , HLA Antigens/immunology , Polymorphism, Genetic/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , COVID-19/epidemiology , COVID-19/virology , Evolution, Molecular , Gene Frequency , HLA Antigens/genetics , HLA Antigens/metabolism , Humans , Immunity, Innate/genetics , Immunity, Innate/immunology , Mutation/genetics , Mutation/immunology , Pandemics , Peptides/immunology , Peptides/metabolism , Polymorphism, Genetic/genetics , SARS-CoV-2/physiology , T-Lymphocytes/cytology , T-Lymphocytes/metabolism
3.
PLoS Pathog ; 18(2): e1010339, 2022 02.
Article in English | MEDLINE | ID: covidwho-1686116

ABSTRACT

Adoptive T-cell immunotherapy has provided promising results in the treatment of viral complications in humans, particularly in the context of immunocompromised patients who have exhausted all other clinical options. The capacity to expand T cells from healthy immune individuals is providing a new approach to anti-viral immunotherapy, offering rapid off-the-shelf treatment with tailor-made human leukocyte antigen (HLA)-matched T cells. While most of this research has focused on the treatment of latent viral infections, emerging evidence that SARS-CoV-2-specific T cells play an important role in protection against COVID-19 suggests that the transfer of HLA-matched allogeneic off-the-shelf virus-specific T cells could provide a treatment option for patients with active COVID-19 or at risk of developing COVID-19. We initially screened 60 convalescent individuals and based on HLA typing and T-cell response profile, 12 individuals were selected for the development of a SARS-CoV-2-specific T-cell bank. We demonstrate that these T cells are specific for up to four SARS-CoV-2 antigens presented by a broad range of both HLA class I and class II alleles. These T cells show consistent functional and phenotypic properties, display cytotoxic potential against HLA-matched targets and can recognize HLA-matched cells infected with different SARS-CoV-2 variants. These observations demonstrate a robust approach for the production of SARS-CoV-2-specific T cells and provide the impetus for the development of a T-cell repository for clinical assessment.


Subject(s)
HLA Antigens/immunology , Immunotherapy, Adoptive , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adult , Epitopes, T-Lymphocyte , Female , HEK293 Cells , Humans , Immunophenotyping , Male , Middle Aged , Young Adult
4.
EBioMedicine ; 73: 103679, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1595805

ABSTRACT

BACKGROUND: The immunogenicity of a two-dose mRNA COVID-19 vaccine regimen is low in kidney transplant (KT) recipients. Here, we provide a thorough assessment of the immunogenicity of a three-dose COVID-19 vaccine regimen in this population. METHODS: We performed a prospective longitudinal study in sixty-one KT recipients given three doses of the BNT162b2 COVID-19 vaccine. We performed semi-structured pharmacovigilance interviews and monitored donor-specific antibodies and kidney function. We compared levels of anti-spike IgG, pseudo-neutralization activity against vaccine homologous and heterologous variants, frequency of spike-specific interferon (IFN)-γ-secreting cells, and antigen-induced cytokine production 28 days after the second and third doses. FINDINGS: Reactions to vaccine were mild. One patient developed donor-specific anti-HLA antibodies after the second dose which could be explained by non-adherence to immunosuppressive therapy. Spike-specific IgG seroconversion raised from 44·3% (n=27) after the second dose to 62·3% (n=38) after the third dose (p<0·05). The mean level of spike-specific IgG increased from 1620 (SD, 3460) to 8772 (SD, 16733) AU/ml (p<0·0001). Serum neutralizing activity increased after the third dose for all variants of concern tested including the Delta variant (p<0·0001). The frequency of spike-specific IFN-γ-secreting cells increased from 19·9 (SD, 56·0) to 64·0 (SD, 76·8) cells/million PBMCs after the third dose (p<0·0001). A significant increase in IFN-γ responses was also observed in patients who remained seronegative after three doses (p<0·0001). INTERPRETATION: A third dose of the BNT162b2 vaccine increases both cross-variant neutralizing antibody and cellular responses in KT recipients with an acceptable tolerability profile. FUNDING: Nice University Hospital, University Cote d'Azur.


Subject(s)
Antibodies, Neutralizing/immunology , COVID-19/immunology , Kidney Transplantation , Aged , Antibodies, Neutralizing/blood , Autoantibodies/blood , /adverse effects , COVID-19/prevention & control , COVID-19/virology , Female , Graft Rejection/prevention & control , HLA Antigens/immunology , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunosuppressive Agents/therapeutic use , Interferon-gamma/metabolism , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/metabolism , Longitudinal Studies , Male , Middle Aged , Risk Factors , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/immunology
6.
Viruses ; 13(12)2021 11 24.
Article in English | MEDLINE | ID: covidwho-1551631

ABSTRACT

Exposure of the adaptive immune system to a pathogen can result in the activation and expansion of T cells capable of recognizing not only the specific antigen but also different unrelated antigens, a process which is commonly referred to as heterologous immunity. While such cross-reactivity is favourable in amplifying protective immune responses to pathogens, induction of T cell-mediated heterologous immune responses to allo-antigens in the setting of solid organ transplantation can potentially lead to allograft rejection. In this review, we provide an overview of murine and human studies investigating the incidence and functional properties of virus-specific memory T cells cross-reacting with allo-antigens and discuss their potential relevance in the context of solid organ transplantation.


Subject(s)
HLA Antigens/immunology , Immunity, Cellular/immunology , Immunity, Heterologous/immunology , Isoantigens/immunology , Animals , Cross Reactions/immunology , Humans , /virology , Mice , Organ Transplantation , T-Lymphocytes/immunology
7.
Elife ; 102021 11 30.
Article in English | MEDLINE | ID: covidwho-1542951

ABSTRACT

T-cell receptors (TCRs) encode clinically valuable information that reflects prior antigen exposure and potential future response. However, despite advances in deep repertoire sequencing, enormous TCR diversity complicates the use of TCR clonotypes as clinical biomarkers. We propose a new framework that leverages experimentally inferred antigen-associated TCRs to form meta-clonotypes - groups of biochemically similar TCRs - that can be used to robustly quantify functionally similar TCRs in bulk repertoires across individuals. We apply the framework to TCR data from COVID-19 patients, generating 1831 public TCR meta-clonotypes from the SARS-CoV-2 antigen-associated TCRs that have strong evidence of restriction to patients with a specific human leukocyte antigen (HLA) genotype. Applied to independent cohorts, meta-clonotypes targeting these specific epitopes were more frequently detected in bulk repertoires compared to exact amino acid matches, and 59.7% (1093/1831) were more abundant among COVID-19 patients that expressed the putative restricting HLA allele (false discovery rate [FDR]<0.01), demonstrating the potential utility of meta-clonotypes as antigen-specific features for biomarker development. To enable further applications, we developed an open-source software package, tcrdist3, that implements this framework and facilitates flexible workflows for distance-based TCR repertoire analysis.


Subject(s)
Antigens, Viral/genetics , COVID-19/immunology , HLA Antigens/genetics , Receptors, Antigen, T-Cell/genetics , SARS-CoV-2/immunology , Antigens, Viral/immunology , Biomarkers , COVID-19/genetics , Complementarity Determining Regions/immunology , Computational Biology/methods , Epitopes/genetics , Epitopes/immunology , Genotype , HLA Antigens/immunology , Humans , Receptors, Antigen, T-Cell/immunology
8.
Front Immunol ; 12: 753849, 2021.
Article in English | MEDLINE | ID: covidwho-1523705

ABSTRACT

Background: CD14+ monocytes present antigens to adaptive immune cells via monocytic human leukocyte antigen receptor (mHLA-DR), which is described as an immunological synapse. Reduced levels of mHLA-DR can display an acquired immune defect, which is often found in sepsis and predisposes for secondary infections and fatal outcomes. Monocytic HLA-DR expression is reliably induced by interferon- γ (IFNγ) therapy. Case Report: We report a case of multidrug-resistant superinfected COVID-19 acute respiratory distress syndrome (ARDS) on extracorporeal membrane oxygenation (ECMO) support. The resistance profiles of the detected Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and Citrobacter freundii isolates were equipped with resistance to all four antibiotic classes including carbapenems (4MRGN) and Cefiderocol in the case of K. pneumoniae. A causal therapeutic antibiotic strategy was not available. Therefore, we measured the immune status of the patient aiming to identify a potential acquired immune deficiency. Monocyte HLA-DR expression identified by FACS analysis revealed an expression level of 34% positive monocytes and suggested severe immunosuppression. We indicated IFNγ therapy, which resulted in a rapid increase in mHLA-DR expression (96%), rapid resolution of invasive bloodstream infection, and discharge from the hospital on day 70. Discussion: Superinfection is a dangerous complication of COVID-19 pneumonia, and sepsis-induced immunosuppression is a risk factor for it. Immunosuppression is expressed by a disturbed antigen presentation of monocytes to cells of the adaptive immune system. The case presented here is remarkable as no validated antibiotic regimen existed against the detected bacterial pathogens causing bloodstream infection and severe pneumonia in a patient suffering from COVID-19 ARDS. Possible restoration of the patient's own immunity by IFNγ was a plausible option to boost the patient's immune system, eliminate the identified 4MRGNs, and allow for lung recovery. This led to the conclusion that immune status monitoring is useful in complicated COVID-19-ARDS and that concomitant IFNγ therapy may support antibiotic strategies. Conclusion: After a compromised immune system has been detected by suppressed mHLA-DR levels, the immune system can be safely reactivated by IFNγ.


Subject(s)
Bacteria/immunology , COVID-19/immunology , Drug Resistance, Multiple/immunology , HLA Antigens/immunology , Interferon-gamma/immunology , Monocytes/immunology , Respiratory Distress Syndrome/immunology , Adult , Humans , Receptors, Interferon/immunology
9.
J Exp Med ; 218(12)2021 12 06.
Article in English | MEDLINE | ID: covidwho-1467277

ABSTRACT

Adaptive immunity is a fundamental component in controlling COVID-19. In this process, follicular helper T (Tfh) cells are a subset of CD4+ T cells that mediate the production of protective antibodies; however, the SARS-CoV-2 epitopes activating Tfh cells are not well characterized. Here, we identified and crystallized TCRs of public circulating Tfh (cTfh) clonotypes that are expanded in patients who have recovered from mild symptoms. These public clonotypes recognized the SARS-CoV-2 spike (S) epitopes conserved across emerging variants. The epitope of the most prevalent cTfh clonotype, S864-882, was presented by multiple HLAs and activated T cells in most healthy donors, suggesting that this S region is a universal T cell epitope useful for booster antigen. SARS-CoV-2-specific public cTfh clonotypes also cross-reacted with specific commensal bacteria. In this study, we identified conserved SARS-CoV-2 S epitopes that activate public cTfh clonotypes associated with mild symptoms.


Subject(s)
COVID-19/immunology , Epitopes, T-Lymphocyte/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes, Helper-Inducer/immunology , Adult , Antibodies, Viral/immunology , Female , HLA Antigens/immunology , Humans , Lymphocyte Activation , Male
10.
Virus Res ; 305: 198579, 2021 11.
Article in English | MEDLINE | ID: covidwho-1433887

ABSTRACT

The SARS-CoV2 mediated Covid-19 pandemic has impacted humankind at an unprecedented scale. While substantial research efforts have focused towards understanding the mechanisms of viral infection and developing vaccines/ therapeutics, factors affecting the susceptibility to SARS-CoV2 infection and manifestation of Covid-19 remain less explored. Given that the Human Leukocyte Antigen (HLA) system is known to vary among ethnic populations, it is likely to affect the recognition of the virus, and in turn, the susceptibility to Covid-19. To understand this, we used bioinformatic tools to probe all SARS-CoV2 peptides which could elicit T-cell response in humans. We also tried to answer the intriguing question of whether these potential epitopes were equally immunogenic across ethnicities, by studying the distribution of HLA alleles among different populations and their share of cognate epitopes. Results indicate that the immune recognition potential of SARS-CoV2 epitopes tend to vary between different ethnic groups. While the South Asians are likely to recognize higher number of CD8-specific epitopes, Europeans are likely to identify higher number of CD4-specific epitopes. We also hypothesize and provide clues that the newer mutations in SARS-CoV2 are unlikely to alter the T-cell mediated immunogenic responses among the studied ethnic populations. The work presented herein is expected to bolster our understanding of the pandemic, by providing insights into differential immunological response of ethnic populations to the virus as well as by gaging the possible effects of mutations in SARS-CoV2 on efficacy of potential epitope-based vaccines through evaluating ∼40,000 viral genomes.


Subject(s)
COVID-19/immunology , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/immunology , Genome, Viral , HLA Antigens/immunology , SARS-CoV-2/immunology , Africa/epidemiology , Alleles , Amino Acid Sequence , Asia/epidemiology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/virology , COVID-19/epidemiology , COVID-19/genetics , COVID-19/pathology , Computational Biology/methods , Disease Susceptibility , Epitopes, B-Lymphocyte/classification , Epitopes, B-Lymphocyte/genetics , Epitopes, T-Lymphocyte/classification , Epitopes, T-Lymphocyte/genetics , Europe/epidemiology , HLA Antigens/classification , HLA Antigens/genetics , Humans , Middle East/epidemiology , Oceania/epidemiology , Principal Component Analysis , RNA, Viral/genetics , RNA, Viral/immunology , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity
11.
Immunogenetics ; 73(6): 459-477, 2021 12.
Article in English | MEDLINE | ID: covidwho-1427234

ABSTRACT

Since 2019, the world was involved with SARS-CoV-2 and consequently, with the announcement by the World Health Organization that COVID-19 was a pandemic, scientific were an effort to obtain the best approach to combat this global dilemma. The best way to prevent the pandemic from spreading further is to use a vaccine against COVID-19. Here, we report the design of a recombinant multi-epitope vaccine against the four proteins spike or crown (S), membrane (M), nucleocapsid (N), and envelope (E) of SARS-CoV-2 using immunoinformatics tools. We evaluated the most antigenic epitopes that bind to HLA class 1 subtypes, along with HLA class 2, as well as B cell epitopes. Beta-defensin 3 and PADRE sequence were used as adjuvants in the structure of the vaccine. KK, GPGPG, and AAY linkers were used to fuse the selected epitopes. The nucleotide sequence was cloned into pET26b(+) vector using restriction enzymes XhoI and NdeI, and HisTag sequence was considered in the C-terminal of the construct. The results showed that the proposed candidate vaccine is a 70.87 kDa protein with high antigenicity and immunogenicity as well as non-allergenic and non-toxic. A total of 95% of the selected epitopes have conservancy with similar sequences. Molecular docking showed a strong binding between the vaccine structure and tool-like receptor (TLR) 7/8. The docking, molecular dynamics, and MM/PBSA analysis showed that the vaccine established a stable interaction with both structures of TLR7 and TLR8. Simulation of immune stimulation by this vaccine showed that it evokes immune responses related to humoral and cellular immunity.


Subject(s)
COVID-19 Vaccines/immunology , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/immunology , SARS-CoV-2/immunology , Amino Acid Sequence , Base Sequence , COVID-19/prevention & control , COVID-19 Vaccines/genetics , COVID-19 Vaccines/metabolism , Computational Biology , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/genetics , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/genetics , HLA Antigens/immunology , Humans , Immunogenicity, Vaccine , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Weight , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , Toll-Like Receptor 7/chemistry , Toll-Like Receptor 8/chemistry , Vaccines, Subunit/genetics , Vaccines, Subunit/immunology , Vaccines, Subunit/metabolism , Vaccinology , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/immunology
13.
Front Immunol ; 12: 728936, 2021.
Article in English | MEDLINE | ID: covidwho-1413272

ABSTRACT

The use of minimal peptide sets offers an appealing alternative for design of vaccines and T cell diagnostics compared to conventional whole protein approaches. T cell immunogenicity towards peptides is contingent on binding to human leukocyte antigen (HLA) molecules of the given individual. HLA is highly polymorphic, and each variant typically presents a different repertoire of peptides. This polymorphism combined with pathogen diversity challenges the rational selection of peptide sets with broad immunogenic potential and population coverage. Here we propose PopCover-2.0, a simple yet highly effective method, for resolving this challenge. The method takes as input a set of (predicted) CD8 and/or CD4 T cell epitopes with associated HLA restriction and pathogen strain annotation together with information on HLA allele frequencies, and identifies peptide sets with optimal pathogen and HLA (class I and II) coverage. PopCover-2.0 was benchmarked on historic data in the context of HIV and SARS-CoV-2. Further, the immunogenicity of the selected SARS-CoV-2 peptides was confirmed by experimentally validating the peptide pools for T cell responses in a panel of SARS-CoV-2 infected individuals. In summary, PopCover-2.0 is an effective method for rational selection of peptide subsets with broad HLA and pathogen coverage. The tool is available at https://services.healthtech.dtu.dk/service.php?PopCover-2.0.


Subject(s)
Epitopes, T-Lymphocyte/immunology , HLA Antigens/genetics , HLA Antigens/immunology , Peptides/immunology , Alleles , Allergy and Immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , COVID-19/prevention & control , Genotype , HLA Antigens/classification , Humans , Immunogenicity, Vaccine , Immunologic Techniques , Peptides/classification , SARS-CoV-2/immunology
14.
HLA ; 96(3): 277-298, 2020 09.
Article in English | MEDLINE | ID: covidwho-1388402

ABSTRACT

We report detailed peptide-binding affinities between 438 HLA Class I and Class II proteins and complete proteomes of seven pandemic human viruses, including coronaviruses, influenza viruses and HIV-1. We contrast these affinities with HLA allele frequencies across hundreds of human populations worldwide. Statistical modelling shows that peptide-binding affinities classified into four distinct categories depend on the HLA locus but that the type of virus is only a weak predictor, except in the case of HIV-1. Among the strong HLA binders (IC50 ≤ 50), we uncovered 16 alleles (the top ones being A*02:02, B*15:03 and DRB1*01:02) binding more than 1% of peptides derived from all viruses, 9 (top ones including HLA-A*68:01, B*15:25, C*03:02 and DRB1*07:01) binding all viruses except HIV-1, and 15 (top ones A*02:01 and C*14:02) only binding coronaviruses. The frequencies of strongest and weakest HLA peptide binders differ significantly among populations from different geographic regions. In particular, Indigenous peoples of America show both higher frequencies of strongest and lower frequencies of weakest HLA binders. As many HLA proteins are found to be strong binders of peptides derived from distinct viral families, and are hence promiscuous (or generalist), we discuss this result in relation to possible signatures of natural selection on HLA promiscuous alleles due to past pathogenic infections. Our findings are highly relevant for both evolutionary genetics and the development of vaccine therapies. However they should not lead to forget that individual resistance and vulnerability to diseases go beyond the sole HLA allelic affinity and depend on multiple, complex and often unknown biological, environmental and other variables.


Subject(s)
Coronavirus Infections/epidemiology , HIV Infections/epidemiology , HLA Antigens/chemistry , Influenza, Human/epidemiology , Pandemics , Peptides/chemistry , Pneumonia, Viral/epidemiology , Severe Acute Respiratory Syndrome/epidemiology , Viral Proteins/chemistry , Africa/epidemiology , Americas/epidemiology , Amino Acid Sequence , Asia/epidemiology , Australia/epidemiology , Betacoronavirus/genetics , Betacoronavirus/immunology , COVID-19 , Computational Biology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Europe/epidemiology , HIV Infections/immunology , HIV Infections/virology , HIV-1/genetics , HIV-1/immunology , HLA Antigens/classification , HLA Antigens/genetics , HLA Antigens/immunology , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/immunology , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H3N2 Subtype/immunology , Influenza A Virus, H7N9 Subtype/genetics , Influenza A Virus, H7N9 Subtype/immunology , Influenza, Human/immunology , Influenza, Human/virology , Kinetics , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/immunology , Peptides/genetics , Peptides/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Protein Binding , SARS Virus/genetics , SARS Virus/immunology , SARS-CoV-2 , Severe Acute Respiratory Syndrome/immunology , Severe Acute Respiratory Syndrome/virology , Viral Proteins/genetics , Viral Proteins/immunology
15.
PLoS One ; 16(8): e0249484, 2021.
Article in English | MEDLINE | ID: covidwho-1379827

ABSTRACT

The human adaptive immune system must generate extraordinary diversity to be able to respond to all possible pathogens. The T-cell repertoire derives this high diversity through somatic recombination of the T-cell receptor (TCR) locus, a random process that results in repertoires that are largely private to each individual. However, factors such as thymic selection and T-cell proliferation upon antigen exposure can affect TCR sharing among individuals. By immunosequencing the TCRß variable region of 426 healthy individuals, we find that, on average, fewer than 1% of TCRß clones are shared between individuals, consistent with largely private TCRß repertoires. However, we detect a significant correlation between increased HLA allele sharing and increased number of shared TCRß clones, with each additional shared HLA allele contributing to an increase in ~0.01% of the total shared TCRß clones, supporting a key role for HLA type in shaping the immune repertoire. Surprisingly, we find that shared antigen exposure to CMV leads to fewer shared TCRß clones, even after controlling for HLA, indicative of a largely private response to major viral antigenic exposure. Consistent with this hypothesis, we find that increased age is correlated with decreased overall TCRß clone sharing, indicating that the pattern of private TCRß clonal expansion is a general feature of the T-cell response to other infectious antigens as well. However, increased age also correlates with increased sharing among the lowest frequency clones, consistent with decreased repertoire diversity in older individuals. Together, all of these factors contribute to shaping the TCRß repertoire, and understanding their interplay has important implications for the use of T cells for therapeutics and diagnostics.


Subject(s)
HLA Antigens/immunology , Histocompatibility Testing , Receptors, Antigen, T-Cell/immunology , Virus Diseases/immunology , Adult , Age Factors , Chronic Disease , Cytomegalovirus Infections/immunology , Histocompatibility Testing/methods , Humans
16.
Front Immunol ; 12: 705772, 2021.
Article in English | MEDLINE | ID: covidwho-1376700

ABSTRACT

Autoimmune diseases (ADs) could occur due to infectious diseases and vaccination programs. Since millions of people are expected to be infected with SARS-CoV-2 and vaccinated against it, autoimmune consequences seem inevitable. Therefore, we have investigated the whole proteome of the SARS-CoV-2 for its ability to trigger ADs. In this regard, the entire proteome of the SARS-CoV-2 was chopped into more than 48000 peptides. The produced peptides were searched against the entire human proteome to find shared peptides with similar experimentally confirmed T-cell and B-cell epitopes. The obtained peptides were checked for their ability to bind to HLA molecules. The possible population coverage was calculated for the most potent peptides. The obtained results indicated that the SARS-CoV-2 and human proteomes share 23 peptides originated from ORF1ab polyprotein, nonstructural protein NS7a, Surface glycoprotein, and Envelope protein of SARS-CoV-2. Among these peptides, 21 peptides had experimentally confirmed equivalent epitopes. Amongst, only nine peptides were predicted to bind to HLAs with known global allele frequency data, and three peptides were able to bind to experimentally confirmed HLAs of equivalent epitopes. Given the HLAs which have already been reported to be associated with ADs, the ESGLKTIL, RYPANSIV, NVAITRAK, and RRARSVAS were determined to be the most harmful peptides of the SARS-CoV-2 proteome. It would be expected that the COVID-19 pandemic and the vaccination against this pathogen could significantly increase the ADs incidences, especially in populations harboring HLA-B*08:01, HLA-A*024:02, HLA-A*11:01 and HLA-B*27:05. The Southeast Asia, East Asia, and Oceania are at higher risk of AD development.


Subject(s)
Autoimmunity , COVID-19 Vaccines/immunology , COVID-19/immunology , Proteome/immunology , SARS-CoV-2/immunology , Viral Proteins/immunology , Autoimmune Diseases/etiology , Autoimmune Diseases/immunology , COVID-19/complications , COVID-19 Vaccines/adverse effects , Computer Simulation , Epitopes, B-Lymphocyte/immunology , HLA Antigens/immunology , Humans , Peptide Fragments/immunology , Peptide Library
18.
Nucleic Acids Res ; 50(D1): D883-D887, 2022 01 07.
Article in English | MEDLINE | ID: covidwho-1358469

ABSTRACT

Rapidly appearing SARS-CoV-2 mutations can affect T cell epitopes, which can help the virus to evade either CD8 or CD4 T-cell responses. We developed T-cell COVID-19 Atlas (T-CoV, https://t-cov.hse.ru) - the comprehensive web portal, which allows one to analyze how SARS-CoV-2 mutations alter the presentation of viral peptides by HLA molecules. The data are presented for common virus variants and the most frequent HLA class I and class II alleles. Binding affinities of HLA molecules and viral peptides were assessed with accurate in silico methods. The obtained results highlight the importance of taking HLA alleles diversity into account: mutation-mediated alterations in HLA-peptide interactions were highly dependent on HLA alleles. For example, we found that the essential number of peptides tightly bound to HLA-B*07:02 in the reference Wuhan variant ceased to be tight binders for the Indian (Delta) and the UK (Alpha) variants. In summary, we believe that T-CoV will help researchers and clinicians to predict the susceptibility of individuals with different HLA genotypes to infection with variants of SARS-CoV-2 and/or forecast its severity.


Subject(s)
COVID-19/immunology , Databases, Factual , HLA Antigens/metabolism , SARS-CoV-2/genetics , Alleles , COVID-19/virology , Codon, Terminator , Epitopes, T-Lymphocyte/immunology , HLA Antigens/genetics , HLA Antigens/immunology , HLA-B7 Antigen/immunology , Host-Pathogen Interactions , Humans , India , Mutation , SARS-CoV-2/pathogenicity , United Kingdom , Viral Proteins/genetics , Viral Proteins/immunology
19.
J Clin Pathol ; 74(8): 528-532, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1318062

ABSTRACT

AIMS: Brazil is nowadays one of the epicentres of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and new therapies are needed to face it. In the context of specific immune response against the virus, a correlation between Major Histocompatibility Complex Class I (MHC-I) and the severity of the disease in patients with COVID-19 has been suggested. Aiming at better understanding the biology of the infection and the immune response against the virus in the Brazilian population, we analysed SARS-CoV-2 protein S peptides in order to identify epitopes able to elicit an immune response mediated by the most frequent MHC-I alleles using in silico methods. METHODS: Our analyses consisted in searching for the most frequent Human Leukocyte Antigen (HLA)-A, HLA-B and HLA-C alleles in the Brazilian population, excluding the genetic isolates; then, we performed: molecular modelling for unsolved structures, MHC-I binding affinity and antigenicity prediction, peptide docking and molecular dynamics of the best fitted MHC-I/protein S complexes. RESULTS: We identified 24 immunogenic epitopes in the SARS-CoV-2 protein S that could interact with 17 different MHC-I alleles (namely, HLA-A*01:01; HLA-A*02:01; HLA-A*11:01; HLA-A*24:02; HLA-A*68:01; HLA-A*23:01; HLA-A*26:01; HLA-A*30:02; HLA-A*31:01; HLA-B*07:02; HLA-B*51:01; HLA-B*35:01; HLA-B*44:02; HLA-B*35:03; HLA-C*05:01; HLA-C*07:01 and HLA-C*15:02) in the Brazilian population. CONCLUSIONS: Being aware of the intrinsic limitations of in silico analysis (mainly the differences between the real and the Protein Data Bank (PDB) structure; and accuracy of the methods for simulate proteasome cleavage), we identified 24 epitopes able to interact with 17 MHC-I more frequent alleles in the Brazilian population that could be useful for the development of strategic methods for vaccines against SARS-CoV-2.


Subject(s)
Epitope Mapping , Epitopes , HLA Antigens/immunology , Histocompatibility Antigens Class I/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Brazil , Gene Frequency , HLA Antigens/genetics , Histocompatibility Antigens Class I/genetics , Host-Pathogen Interactions , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Binding , Protein Conformation , SARS-CoV-2/pathogenicity
20.
Nat Commun ; 12(1): 4196, 2021 07 07.
Article in English | MEDLINE | ID: covidwho-1301167

ABSTRACT

Monoclonal antibodies targeting a variety of epitopes have been isolated from individuals previously infected with SARS-CoV-2, but the relative contributions of these different antibody classes to the polyclonal response remains unclear. Here we use a yeast-display system to map all mutations to the viral spike receptor-binding domain (RBD) that escape binding by representatives of three potently neutralizing classes of anti-RBD antibodies with high-resolution structures. We compare the antibody-escape maps to similar maps for convalescent polyclonal plasmas, including plasmas from individuals from whom some of the antibodies were isolated. While the binding of polyclonal plasma antibodies are affected by mutations across multiple RBD epitopes, the plasma-escape maps most resemble those of a single class of antibodies that target an epitope on the RBD that includes site E484. Therefore, although the human immune system can produce antibodies that target diverse RBD epitopes, in practice the polyclonal response to infection is skewed towards a single class of antibodies targeting an epitope that is already undergoing rapid evolution.


Subject(s)
Antibodies, Viral/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Binding Sites , COVID-19/immunology , Epitopes , HLA Antigens/immunology , Humans , Immune Evasion/genetics , Models, Molecular , Mutation , Neutralization Tests , Protein Domains , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry
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