1. High burden of viruses and bacterial pathobionts drives heightened nasal innate immunity in children.
- Author
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Watkins TA, Green AB, Amat JAR, Cheemarla NR, Hänsel K, Lozano R, Dudgeon SN, Germain G, Landry ML, Schulz WL, and Foxman EF
- Subjects
- Humans, Child, Preschool, Infant, Child, Female, Male, Nasopharynx immunology, Nasopharynx virology, Nasopharynx microbiology, Viral Load, Nasal Mucosa immunology, Nasal Mucosa virology, Nasal Mucosa microbiology, Cytokines metabolism, Cytokines immunology, Host-Pathogen Interactions immunology, Adolescent, Nose immunology, Nose virology, Nose microbiology, Coinfection immunology, Coinfection virology, Immunity, Innate immunology, COVID-19 immunology, COVID-19 virology, SARS-CoV-2 immunology
- Abstract
Studies during the COVID-19 pandemic showed that children had heightened nasal innate immune responses compared with adults. To evaluate the role of nasal viruses and bacteria in driving these responses, we performed cytokine profiling and comprehensive, symptom-agnostic testing for respiratory viruses and bacterial pathobionts in nasopharyngeal samples from children tested for SARS-CoV-2 in 2021-22 (n = 467). Respiratory viruses and/or pathobionts were highly prevalent (82% of symptomatic and 30% asymptomatic children; 90 and 49% for children <5 years). Virus detection and load correlated with the nasal interferon response biomarker CXCL10, and the previously reported discrepancy between SARS-CoV-2 viral load and nasal interferon response was explained by viral coinfections. Bacterial pathobionts correlated with a distinct proinflammatory response with elevated IL-1β and TNF but not CXCL10. Furthermore, paired samples from healthy 1-year-olds collected 1-2 wk apart revealed frequent respiratory virus acquisition or clearance, with mucosal immunophenotype changing in parallel. These findings reveal that frequent, dynamic host-pathogen interactions drive nasal innate immune activation in children., (© 2024 Watkins et al.)
- Published
- 2024
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