MORHART PATRICK, KEHL SVEN, SCHUH WOLFGANG, HERMES KATHARINA, MELTENDORF STEFAN, NEUBERT ANTJE, SCHNEIDER MICHAEL, BRUNNER-WEINZIERL MONIKA, SCHNEIDER HOLM, LINGEL HOLGER. Age-related Differences in Immune Reactions to SARS-CoV-2 Spike and Nucleocapsid Antigens.
In Vivo 2023;
37:70-78. [PMID:
36593041 PMCID:
PMC9843773 DOI:
10.21873/invivo.13055]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND/AIM
The manifestation and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections show a clear correlation to the age of a patient. The younger a person, the less likely the infection results in significant illness. To explore the immunological characteristics behind this phenomenon, we studied the course of SARS-CoV-2 infections in 11 households, including 8 children and 6 infants/neonates of women who got infected with SARS-CoV-2 during pregnancy.
MATERIALS AND METHODS
We investigated the immune responses of peripheral blood mononuclear cells (PBMCs), umbilical cord blood mononuclear cells (UCBCs), and T cells against spike and nucleocapsid antigens of SARS-COV-2 by flow cytometry and cytokine secretion assays.
RESULTS
Upon peptide stimulation, UCBC from neonates showed a strongly reduced IFN-γ production, as well as lower levels of IL-5, IL-13, and TNF-α alongside with decreased frequencies of surface CD137/PD-1 co-expressing CD4+ and CD+8 T cells compared with adult PBMCs. The PBMC response of older children instead was characterized by elevated frequencies of IFN-γ+ CD4+ T cells, but significantly lower levels of multiple cytokines (IL-5, IL-6, IL-9, IL-10, IL-17A, and TNF-α) and a marked shift of the CD4+/CD8+ T-cell ratio towards CD8+ T cells in comparison to adults.
CONCLUSION
The increased severity of SARS-CoV-2 infections in adults could result from the strong cytokine production and lower potential to immunomodulate the excessive inflammation, while the limited IFN-γ production of responding T cells in infants/neonates and the additional higher frequencies of CD8+ T cells in older children may provide advantages during the course of a SARS-CoV-2 infection.
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