Yu M, Charles A, Cagigi A, Christ W, Österberg B, Falck-Jones S, Azizmohammadi L, Åhlberg E, Falck-Jones R, Svensson J, Nie M, Warnqvist A, Hellgren F, Lenart K, Arcoverde Cerveira R, Ols S, Lindgren G, Lin A, Maecker H, Bell M, Johansson N, Albert J, Sundling C, Czarnewski P, Klingström J, Färnert A, Loré K, Smed-Sörensen A
Nat Commun 14 (1) 2164 [2023-04-15; online 2023-04-15]
Effective humoral immune responses require well-orchestrated B and T follicular helper (Tfh) cell interactions. Whether these interactions are impaired and associated with COVID-19 disease severity is unclear. Here, longitudinal blood samples across COVID-19 disease severity are analysed. We find that during acute infection SARS-CoV-2-specific circulating Tfh (cTfh) cells expand with disease severity. SARS-CoV-2-specific cTfh cell frequencies correlate with plasmablast frequencies and SARS-CoV-2 antibody titers, avidity and neutralization. Furthermore, cTfh cells but not other memory CD4 T cells, from severe patients better induce plasmablast differentiation and antibody production compared to cTfh cells from mild patients. However, virus-specific cTfh cell development is delayed in patients that display or later develop severe disease compared to those with mild disease, which correlates with delayed induction of high-avidity neutralizing antibodies. Our study suggests that impaired generation of functional virus-specific cTfh cells delays high-quality antibody production at an early stage, potentially enabling progression to severe disease.