Abstract
Children have reduced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates and a substantially lower risk for developing severe coronavirus disease 2019 compared with adults. However, the molecular mechanisms underlying protection in younger age groups remain unknown. Here we characterize the single-cell transcriptional landscape in the upper airways of SARS-CoV-2-negative (n = 18) and age-matched SARS-CoV-2-positive (n = 24) children and corresponding samples from adults (n = 44), covering an age range of 4 weeks to 77 years. Children displayed higher basal expression of relevant pattern recognition receptors such as MDA5 (IFIH1) and RIG-I (DDX58) in upper airway epithelial cells, macrophages and dendritic cells, resulting in stronger innate antiviral responses upon SARS-CoV-2 infection than in adults. We further detected distinct immune cell subpopulations including KLRC1 (NKG2A)+ cytotoxic T cells and a CD8+ T cell population with a memory phenotype occurring predominantly in children. Our study provides evidence that the airway immune cells of children are primed for virus sensing, resulting in a stronger early innate antiviral response to SARS-CoV-2 infection than in adults.
【초록키워드】 SARS-CoV-2, Macrophage, coronavirus, SARS-COV-2 infection, children, molecular mechanism, virus, dendritic cells, airway, memory, Adults, MDA5, phenotype, RIG-I, age, infection rate, upper airway, group, expression, single-cell, CD8+ T cell, Evidence, antiviral response, DDX58, Immune cell, airway epithelial cells, pattern recognition receptor, Cytotoxic T cell, acute respiratory syndrome, severe coronavirus disease, lower risk, subpopulation, IFIH1, transcriptional, resulting, reduced, provide, KLRC1, 【제목키워드】 Antiviral, Innate immunity, SARS-COV-2 infection, children, Control, upper airway,