Distinct T cell polyfunctional profile in SARS-CoV-2 seronegative children associated with endemic human coronavirus cross-reactivity

• Published in: iScience 2024-01, Vol.27 (1), p.108728-108728, Article 108728
• Main Authors: Benede, Ntombi, Tincho, Marius B., Walters, Avril, Subbiah, Vennesa, Ngomti, Amkele, Baguma, Richard, Butters, Claire, Hahnle, Lina, Mennen, Mathilda, Skelem, Sango, Adriaanse, Marguerite, Facey-Thomas, Heidi, Scott, Christiaan, Day, Jonathan, Spracklen, Timothy F., van Graan, Strauss, Balla, Sashkia R., Moyo-Gwete, Thandeka, Moore, Penny L., MacGinty, Rae, Botha, Maresa, Workman, Lesley, Johnson, Marina, Goldblatt, David, Zar, Heather J., Ntusi, Ntobeko A.B., Zühlke, Liesl, Webb, Kate, Riou, Catherine, Burgers, Wendy A., Keeton, Roanne S.
• Format: Article
• Language: English
• Subjects: Components of the immune system; Immune response; Immunology; Virology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2023.108728

SARS-CoV-2 infection in children typically results in asymptomatic or mild disease. There is a paucity of studies on SARS-CoV-2 antiviral immunity in African children. We investigated SARS-CoV-2-specific T cell responses in 71 unvaccinated asymptomatic South African children who were seropositive or seronegative for SARS-CoV-2. SARS-CoV-2-specific CD4+ T cell responses were detectable in 83% of seropositive and 60% of seronegative children. Although the magnitude of the CD4+ T cell response did not differ significantly between the two groups, their functional profiles were distinct, with SARS-CoV-2 seropositive children exhibiting a higher proportion of polyfunctional T cells compared to their seronegative counterparts. The frequency of SARS-CoV-2-specific CD4+ T cells in seronegative children was associated with the endemic human coronavirus (HCoV) HKU1 IgG response. Overall, the presence of SARS-CoV-2-responding T cells in seronegative children may result from cross-reactivity to endemic coronaviruses and could contribute to the relative protection from disease observed in SARS-CoV-2-infected children. [Display omitted] •SARS-CoV-2-specific T cell responses are detected in 60% of seronegative children•Similar magnitude T cell response between seropositive and seronegative children•Seronegative children exhibit a lower proportion of polyfunctional T cells•CoV-2-specific T cell and endemic HKU1 IgG responses correlate in seronegative children Immunology; Immune response; Components of the immune system; Virology