tetano
Editor, Senior Moderator
Front Immunol
. 2022 Feb 7;13:817876.
doi: 10.3389/fimmu.2022.817876. eCollection 2022.
Children and Adults With Mild COVID-19: Dynamics of the Memory T Cell Response up to 10 Months
Patricia Kaaijk[SUP] 1 [/SUP], Verónica Olivo Pimentel[SUP] 1 [/SUP], Maarten E Emmelot[SUP] 1 [/SUP], Martien Poelen[SUP] 1 [/SUP], Alper Cevirgel[SUP] 1 [/SUP], Rutger M Schepp[SUP] 1 [/SUP], Gerco den Hartog[SUP] 1 [/SUP], Daphne F M Reukers[SUP] 1 [/SUP], Lisa Beckers[SUP] 1 [/SUP], Josine van Beek[SUP] 1 [/SUP], Cécile A C M van Els[SUP] 1 2 [/SUP], Adam Meijer[SUP] 1 [/SUP], Nynke Y Rots[SUP] 1 [/SUP], Jelle de Wit[SUP] 1 [/SUP]
Affiliations
Abstract
Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to considerable morbidity/mortality worldwide, but most infections, especially among children, have a mild course. However, it remains largely unknown whether infected children develop cellular immune memory.
Methods: To determine whether a memory T cell response is being developed, we performed a longitudinal assessment of the SARS-CoV-2-specific T cell response by IFN-γ ELISPOT and activation marker analyses of peripheral blood samples from unvaccinated children and adults with mild-to-moderate COVID-19.
Results: Upon stimulation of PBMCs with heat-inactivated SARS-CoV-2 or overlapping peptides of spike (S-SARS-CoV-2) and nucleocapsid proteins, we found S-SARS-CoV-2-specific IFN-γ T cell responses in infected children (83%) and adults (100%) that were absent in unexposed controls. Frequencies of SARS-CoV-2-specific T cells were higher in infected adults, especially in those with moderate symptoms, compared to infected children. The S-SARS-CoV-2 IFN-γ T cell response correlated with S1-SARS-CoV-2-specific serum antibody concentrations. Predominantly, effector memory CD4[SUP]+[/SUP] T cells of a Th1 phenotype were activated upon exposure to SARS-CoV-2 antigens. Frequencies of SARS-CoV-2-specific T cells were significantly reduced at 10 months after symptom onset, while S1-SARS-CoV-2-specific IgG concentrations were still detectable in 90% of all children and adults.
Conclusions: Our data indicate that an antigen-specific T cell and antibody response is developed after mild SARS-CoV-2 infection in children and adults. It remains to be elucidated to what extent this SARS-CoV-2-specific response can contribute to an effective recall response after reinfection.
Keywords: COVID-19; SARS-CoV-2; T cell immunity; adaptive immunity; antibody response; children; cytokines; mild symptoms.
. 2022 Feb 7;13:817876.
doi: 10.3389/fimmu.2022.817876. eCollection 2022.
Children and Adults With Mild COVID-19: Dynamics of the Memory T Cell Response up to 10 Months
Patricia Kaaijk[SUP] 1 [/SUP], Verónica Olivo Pimentel[SUP] 1 [/SUP], Maarten E Emmelot[SUP] 1 [/SUP], Martien Poelen[SUP] 1 [/SUP], Alper Cevirgel[SUP] 1 [/SUP], Rutger M Schepp[SUP] 1 [/SUP], Gerco den Hartog[SUP] 1 [/SUP], Daphne F M Reukers[SUP] 1 [/SUP], Lisa Beckers[SUP] 1 [/SUP], Josine van Beek[SUP] 1 [/SUP], Cécile A C M van Els[SUP] 1 2 [/SUP], Adam Meijer[SUP] 1 [/SUP], Nynke Y Rots[SUP] 1 [/SUP], Jelle de Wit[SUP] 1 [/SUP]
Affiliations
- PMID: 35197982
- PMCID: PMC8858984
- DOI: 10.3389/fimmu.2022.817876
Abstract
Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to considerable morbidity/mortality worldwide, but most infections, especially among children, have a mild course. However, it remains largely unknown whether infected children develop cellular immune memory.
Methods: To determine whether a memory T cell response is being developed, we performed a longitudinal assessment of the SARS-CoV-2-specific T cell response by IFN-γ ELISPOT and activation marker analyses of peripheral blood samples from unvaccinated children and adults with mild-to-moderate COVID-19.
Results: Upon stimulation of PBMCs with heat-inactivated SARS-CoV-2 or overlapping peptides of spike (S-SARS-CoV-2) and nucleocapsid proteins, we found S-SARS-CoV-2-specific IFN-γ T cell responses in infected children (83%) and adults (100%) that were absent in unexposed controls. Frequencies of SARS-CoV-2-specific T cells were higher in infected adults, especially in those with moderate symptoms, compared to infected children. The S-SARS-CoV-2 IFN-γ T cell response correlated with S1-SARS-CoV-2-specific serum antibody concentrations. Predominantly, effector memory CD4[SUP]+[/SUP] T cells of a Th1 phenotype were activated upon exposure to SARS-CoV-2 antigens. Frequencies of SARS-CoV-2-specific T cells were significantly reduced at 10 months after symptom onset, while S1-SARS-CoV-2-specific IgG concentrations were still detectable in 90% of all children and adults.
Conclusions: Our data indicate that an antigen-specific T cell and antibody response is developed after mild SARS-CoV-2 infection in children and adults. It remains to be elucidated to what extent this SARS-CoV-2-specific response can contribute to an effective recall response after reinfection.
Keywords: COVID-19; SARS-CoV-2; T cell immunity; adaptive immunity; antibody response; children; cytokines; mild symptoms.