In:
The Journal of Immunology, The American Association of Immunologists, Vol. 210, No. 1_Supplement ( 2023-05-01), p. 75.20-75.20
Abstract:
The pre-existing SARS-CoV-2-reactive T cells identified in unexposed individuals are likely induced by prior infections with seasonal coronaviruses and may modulate disease outcomes. By assessing humoral and cellular immunity in paired samples from SARS-CoV-2 unexposed children at ages 2 and 6 (n=16), and SARS-CoV-2 seronegative adults (n=94, ages 26–83), this study aims to elucidate how age influences the immune responses against coronaviruses. Using flow cytometry, the phenotype and function of seasonal coronavirus OC43-specific and pre-existing SARS-CoV-2-reactive memory (m) CD4 +T cells were characterized after a 10h stimulation with viral peptides. The frequency of SARS-CoV-2-reactive mCD4 +T cells were closely linked with the OC43-specific responses in all age groups. However, a positive response to either OC43- or SARS-CoV-2-derived peptides was more common at age 6 than in adults. Similarly, the functional capacity, defined by IFN-γ, IL-2 and TNF expression, of both OC43-specific and SARS-CoV-2-reactive mCD4 +T cells peaked at age 6 and then declined with age. Age-dependent phenotypic markers were also identified, including CD226, TIGIT and CD38. Lastly, in contrast to Rhinovirus, EBV, Influenza and other coronaviruses, OC43 seroprevalence did not increase between ages 2 and 6, or from childhood to adulthood, further establishing OC43 as a childhood infection. Our results show that memory responses to coronaviruses develop at a young age and exhibit age-dependent qualities, findings which may aid in future vaccine development. In addition, the high prevalence and functional capacity of pre-existing SARS-CoV-2-reactive mCD4 +T cells at age 6 may contribute to the low incidence of severe COVID-19 in this age group.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.210.Supp.75.20
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2023
detail.hit.zdb_id:
1475085-5
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