SARS-CoV-2 infection of children leads to a mild illness and the immunological differences with adults are unclear. Here, we report SARS-CoV-2 specific T cell responses in infected adults and children and find that the acute and memory CD4 + T cell responses to structural SARS-CoV-2 proteins increase with age, whereas CD8 + T cell responses increase with time post-infection. Infected children have lower CD4 + and CD8 + T cell responses to SARS-CoV-2 structural and ORF1ab proteins when compared with infected adults, comparable T cell polyfunctionality and reduced CD4 + T cell effector memory. Compared with adults, children have lower levels of antibodies to β-coronaviruses, indicating differing baseline immunity. Total T follicular helper responses are increased, whilst monocyte numbers are reduced, indicating rapid adaptive co-ordination of the T and B cell responses and differing levels of inflammation. Therefore, reduced prior β-coronavirus immunity and reduced T cell activation in children might drive milder COVID-19 pathogenesis. Why children are generally less susceptible than adults to COVID-19 is unclear and has not extensively been examined longitudinally. Here the authors compare antibodies, cytokines and immune cell responses in adults and children over 6 months post-infection showing, among other things, a reduced CD4+ and CD8+ T cell response in children.
【저자키워드】 viral infection, cellular immunity, 【초록키워드】 COVID-19, antibodies, SARS-CoV-2, Inflammation, Cytokines, adaptive, Immunity, SARS-COV-2 infection, children, cytokine, CD4, CD8, memory, monocyte, Protein, Adults, T cell, COVID-19 pathogenesis, response, T cell responses, age, T cell response, CD8+ T cell, T cell activation, ORF1ab, B cell response, Post-infection, CD4+, SARS-CoV-2 protein, mild illness, immune cell responses, infected children, effector memory, β-coronavirus, β-Coronaviruses, T and B cell responses, susceptible, immunological, CD8+ T cell response, ordination, examined, reduced, less, comparable, Total, baseline, follicular, immune cell response, levels of antibody, 【제목키워드】 SARS-CoV-2, children, Infection, age, T cell response,