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Identification and characterization of a SARS-CoV-2 specific CD8⁺ T cell response with immunodominant features.

ABSTRACT: The COVID-19 pandemic caused by SARS-CoV-2 is a continuous challenge worldwide, and there is an urgent need to map the landscape of immunogenic and immunodominant epitopes recognized by CD8⁺ T cells. Here, we analyze samples from 31 patients with COVID-19 for CD8⁺ T cell recognition of 500 peptide-HLA class I complexes, restricted by 10 common HLA alleles. We identify 18 CD8⁺ T cell recognized SARS-CoV-2 epitopes, including an epitope with immunodominant features derived from ORF1ab and restricted by HLA-A*01:01. In-depth characterization of SARS-CoV-2-specific CD8⁺ T cell responses of patients with acute critical and severe disease reveals high expression of NKG2A, lack of cytokine production and a gene expression profile inhibiting T cell re-activation and migration while sustaining survival. SARS-CoV-2-specific CD8⁺ T cell responses are detectable up to 5 months after recovery from critical and severe disease, and these responses convert from dysfunctional effector to functional memory CD8⁺ T cells during convalescence.

SUBMITTER: Gangaev A

PROVIDER: S-EPMC8110804 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Identification and characterization of a SARS-CoV-2 specific CD8 T cell response with immunodominant features

Project description:The COVID-19 pandemic caused by SARS-CoV-2 is a continuous challenge worldwide, and there is an urgent need to map the landscape of immunogenic and immunodominant epitopes recognized by CD8 T cells. Here, we analyze samples from 31 COVID-19 patients for CD8 T cell recognition of 500 peptide-HLA class I complexes, restricted by 10 common HLA alleles. We identify 18 CD8 T cell recognized SARS-CoV-2 epitopes, including an epitope with immunodominant features derived from ORF1ab and restricted by HLA-A*01:01. In-depth characterization of SARS-CoV-2-specific CD8 T cell responses of patients with acute critical and severe disease reveals high expression of NKG2A, lack of cytokine production and a gene expression profile inhibiting T cell re-activation and migration while sustaining survival. SARS-CoV-2-specific CD8 T cell responses are detectable up to 5 months post recovery from critical and severe disease, and these responses convert from dysfunctional effector to functional memory CD8 T cells during convalescence.

2021-03-25 | GSE169503 | GEO

Identification and characterization of a SARS-CoV-2 specific CD8 T cell response with immunodominant features

Project description:Identification and characterization of a SARS-CoV-2 specific CD8 T cell response with immunodominant features

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CD8+ T cells specific for an immunodominant SARS-CoV-2 nucleocapsid epitope cross-react with selective seasonal coronaviruses.

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Suboptimal SARS-CoV-2-specific CD8+ T cell response associated with the prominent HLA-A*02:01 phenotype.

Project description:An improved understanding of human T cell-mediated immunity in COVID-19 is important for optimizing therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8+ T cell memory to peptides presented by common HLA types like HLA-A2, which enhances recovery and diminishes clinical severity upon reinfection. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the clonal expansion of SARS-CoV-2-specific CD8+ and CD4+ T cells in vitro, with CD4+ T cells being robust. We identified two HLA-A*02:01-restricted SARS-CoV-2-specfic CD8+ T cell epitopes, A2/S269-277 and A2/Orf1ab3183-3191 Using peptide-HLA tetramer enrichment, direct ex vivo assessment of A2/S269 +CD8+ and A2/Orf1ab3183 +CD8+ populations indicated that A2/S269 +CD8+ T cells were detected at comparable frequencies (∼1.3 × 10-5) in acute and convalescent HLA-A*02:01+ patients. These frequencies were higher than those found in uninfected HLA-A*02:01+ donors (∼2.5 × 10-6), but low when compared to frequencies for influenza-specific (A2/M158) and Epstein-Barr virus (EBV)-specific (A2/BMLF1280) (∼1.38 × 10-4) populations. Phenotyping A2/S269 +CD8+ T cells from COVID-19 convalescents ex vivo showed that A2/S269 +CD8+ T cells were predominantly negative for CD38, HLA-DR, PD-1, and CD71 activation markers, although the majority of total CD8+ T cells expressed granzymes and/or perforin. Furthermore, the bias toward naïve, stem cell memory and central memory A2/S269 +CD8+ T cells rather than effector memory populations suggests that SARS-CoV-2 infection may be compromising CD8+ T cell activation. Priming with appropriate vaccines may thus be beneficial for optimizing CD8+ T cell immunity in COVID-19.

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