tetano
Editor, Senior Moderator
Front Immunol
. 2025 Feb 28:16:1510436.
doi: 10.3389/fimmu.2025.1510436. eCollection 2025. T cell receptor usage and epitope specificity amongst CD8[SUP]+[/SUP] and CD4[SUP]+[/SUP] SARS-CoV-2-specific T cells
Ulrik Fahnøe[SUP] 1 2 3 [/SUP], Shan Feng[SUP] 1 2 3 [/SUP], Alexander P Underwood[SUP] 1 2 3 [/SUP], Kivin Jacobsen[SUP] 4 [/SUP], Amir Ameri[SUP] 4 [/SUP], Thomas H Blicher[SUP] 4 [/SUP], Christina S Sølund[SUP] 1 2 3 [/SUP], Brad R Rosenberg[SUP] 5 [/SUP], Liselotte Brix[SUP] 4 [/SUP], Nina Weis[SUP] 3 6 [/SUP], Jens Bukh[SUP] 1 2 3 [/SUP]
Affiliations
Introduction: The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has highlighted the critical importance of understanding protective long-lasting immune responses. This study investigates the epitope specificity, T cell receptor (TCR) usage, and phenotypic changes in SARS-CoV-2-specfic CD8[SUP]+[/SUP] and CD4[SUP]+[/SUP] T cells over time in convalescent individuals with COVID-19.
Methods: Peripheral blood mononuclear cells (PBMCs) were collected from 28 unvaccinated individuals with primary SARS-CoV-2 infection (6 identified as the D614G variant, clade 20C) and analyzed up to 12 months post-symptom onset. Antigen-specific CD8[SUP]+[/SUP] and CD4[SUP]+[/SUP] T cells were analyzed using flow cytometry and single-cell RNA sequencing (scRNAseq) using specific dextramer and antibody reagents. TCR clonotypes and activation markers were characterized to explore T cell dynamics.
Results: SARS-CoV-2-specific CD8[SUP]+[/SUP] T cells exhibited waning frequencies long-term, transitioning from memory-like to a naïve-like state. scRNAseq revealed specificity against both spike and non-spike antigens with increased CD95 and CD127 expression over time, indicating that naïve-like T cells may represent stem cell memory T cells, which are multipotent and self-renewing, likely important for long-lived immunity. TCR clonal expansion was observed mainly in memory T cells, with overlapping TCR beta chain (TRB)-complementary determining region 3 (CDR3) sequences between participants, suggesting shared public TCR epitope-specific repertoires against SARS-CoV-2. Further, unique spike-specific CD4[SUP]+[/SUP] T cells with high CD95 and CD127 expression were identified, which may play a crucial role in long-term protection.
Discussion: This study highlights epitope-specificity heterogeneity, with some immunodominant responses, and suggests a potential role for long-lived SARS-CoV-2-specific T cell immunity. Shared TCR repertoires offers insights into cross-reactive and protective T cell clones, providing valuable information for optimizing vaccine strategies against emerging SARS-CoV-2 variants. The findings underscore the critical role of cellular immunity in long-term protection against SARS-CoV-2 and emphasizes the importance of understanding T cell dynamics.
Keywords: CD4+ -specific cells; CD8+ -specific cells; COVID-19; SARS-CoV-2; T cells; flow cytometry; single-cell RNA sequencing; transcriptomics.
. 2025 Feb 28:16:1510436.
doi: 10.3389/fimmu.2025.1510436. eCollection 2025. T cell receptor usage and epitope specificity amongst CD8[SUP]+[/SUP] and CD4[SUP]+[/SUP] SARS-CoV-2-specific T cells
Ulrik Fahnøe[SUP] 1 2 3 [/SUP], Shan Feng[SUP] 1 2 3 [/SUP], Alexander P Underwood[SUP] 1 2 3 [/SUP], Kivin Jacobsen[SUP] 4 [/SUP], Amir Ameri[SUP] 4 [/SUP], Thomas H Blicher[SUP] 4 [/SUP], Christina S Sølund[SUP] 1 2 3 [/SUP], Brad R Rosenberg[SUP] 5 [/SUP], Liselotte Brix[SUP] 4 [/SUP], Nina Weis[SUP] 3 6 [/SUP], Jens Bukh[SUP] 1 2 3 [/SUP]
Affiliations
- PMID: 40092978
- PMCID: PMC11906682
- DOI: 10.3389/fimmu.2025.1510436
Introduction: The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has highlighted the critical importance of understanding protective long-lasting immune responses. This study investigates the epitope specificity, T cell receptor (TCR) usage, and phenotypic changes in SARS-CoV-2-specfic CD8[SUP]+[/SUP] and CD4[SUP]+[/SUP] T cells over time in convalescent individuals with COVID-19.
Methods: Peripheral blood mononuclear cells (PBMCs) were collected from 28 unvaccinated individuals with primary SARS-CoV-2 infection (6 identified as the D614G variant, clade 20C) and analyzed up to 12 months post-symptom onset. Antigen-specific CD8[SUP]+[/SUP] and CD4[SUP]+[/SUP] T cells were analyzed using flow cytometry and single-cell RNA sequencing (scRNAseq) using specific dextramer and antibody reagents. TCR clonotypes and activation markers were characterized to explore T cell dynamics.
Results: SARS-CoV-2-specific CD8[SUP]+[/SUP] T cells exhibited waning frequencies long-term, transitioning from memory-like to a naïve-like state. scRNAseq revealed specificity against both spike and non-spike antigens with increased CD95 and CD127 expression over time, indicating that naïve-like T cells may represent stem cell memory T cells, which are multipotent and self-renewing, likely important for long-lived immunity. TCR clonal expansion was observed mainly in memory T cells, with overlapping TCR beta chain (TRB)-complementary determining region 3 (CDR3) sequences between participants, suggesting shared public TCR epitope-specific repertoires against SARS-CoV-2. Further, unique spike-specific CD4[SUP]+[/SUP] T cells with high CD95 and CD127 expression were identified, which may play a crucial role in long-term protection.
Discussion: This study highlights epitope-specificity heterogeneity, with some immunodominant responses, and suggests a potential role for long-lived SARS-CoV-2-specific T cell immunity. Shared TCR repertoires offers insights into cross-reactive and protective T cell clones, providing valuable information for optimizing vaccine strategies against emerging SARS-CoV-2 variants. The findings underscore the critical role of cellular immunity in long-term protection against SARS-CoV-2 and emphasizes the importance of understanding T cell dynamics.
Keywords: CD4+ -specific cells; CD8+ -specific cells; COVID-19; SARS-CoV-2; T cells; flow cytometry; single-cell RNA sequencing; transcriptomics.