Imbalanced Immune Response of T-Cell and B-Cell Subsets in Patients with Moderate and Severe COVID-19
А. С. Головкин, Olga Kalinina, Vadim Bezrukikh, Arthur Aquino, Ekaterina Zaikova, Tatyana L. Karonova, Olesya Melnik, Elena Vasilieva, Igor Kudryavtsev
Abstract
BACKGROUND: The immunological changes associated with COVID-19 are largely unknown. METHODS: ≤ 300 mmHg, permanent oxygen therapy, qSOFA > 2) infection, and 37 healthy donors (HD) were enrolled. Circulating T- and B-cell subsets were analyzed by flow cytometry. RESULTS: CD4+Th cells were skewed toward Th2-like phenotypes within CD45RA+CD62L- (CM) and CD45RA-CD62L- (EM) cells in patients with severe COVID-19, while CM CCR6+ Th17-like cells were decreased if compared with HD. Within CM Th17-like cells "classical" Th17-like cells were increased and Th17.1-like cells were decreased in severe COVID-19 cases. Circulating CM follicular Th-like (Tfh) cells were decreased in all COVID-19 patients, and Tfh17-like cells represented the most predominant subset in severe COVID-19 cases. Both groups of patients showed increased levels of IgD-CD38++ B cells, while the levels of IgD+CD38- and IgD-CD38- were decreased. The frequency of IgD+CD27+ and IgD-CD27+ B cells was significantly reduced in severe COVID-19 cases. CONCLUSIONS: We showed an imbalance within almost all circulating memory Th subsets during acute COVID-19 and showed that altered Tfh polarization led to a dysregulated humoral immune response.