Abstract
T cells are involved in control of coronavirus disease 2019 (COVID-19), but limited knowledge is available on the relationship between antigen-specific T cell response and disease severity. Here, we used flow cytometry to assess the magnitude, function, and phenotype of SARS coronavirus 2–specific (SARS-CoV-2–specific) CD4+ T cells in 95 hospitalized COVID-19 patients, 38 of them being HIV-1 and/or tuberculosis (TB) coinfected, and 38 non–COVID-19 patients. We showed that SARS-CoV-2–specific CD4+ T cell attributes, rather than magnitude, were associated with disease severity, with severe disease being characterized by poor polyfunctional potential, reduced proliferation capacity, and enhanced HLA-DR expression. Moreover, HIV-1 and TB coinfection skewed the SARS-CoV-2 T cell response. HIV-1–mediated CD4+ T cell depletion associated with suboptimal T cell and humoral immune responses to SARS-CoV-2, and a decrease in the polyfunctional capacity of SARS-CoV-2–specific CD4+ T cells was observed in COVID-19 patients with active TB. Our results also revealed that COVID-19 patients displayed reduced frequency of Mycobacterium tuberculosis–specific CD4+ T cells, with possible implications for TB disease progression. These results corroborate the important role of SARS-CoV-2–specific T cells in COVID-19 pathogenesis and support the concept of altered T cell functions in patients with severe disease.
Authors
Catherine Riou, Elsa du Bruyn, Cari Stek, Remy Daroowala, Rene T. Goliath, Fatima Abrahams, Qonita Said-Hartley, Brian W. Allwood, Nei-Yuan Hsiao, Katalin A. Wilkinson, Cecilia S. Lindestam Arlehamn, Alessandro Sette, Sean Wasserman, Robert J. Wilkinson, on behalf of the HIATUS consortium
Figure 1
Measures of COVID-19 disease severity.
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)