Insights into the T-cell response to SARS-CoV-2

Abstract

Following infection with SARS-CoV-2, cellular components of the adaptive immune system play a crucial role in eliminating the virus. Specifically, virus-specific CD4+ and CD8+ T cells generate effector cytokines and display cytotoxic activity. A number of studies carried out during the COVID-19 pandemic highlighted the importance of CD4+ T cells, CD8+ T cells, and memory cells in this process. T-cell responses emerge early and contribute to protection, but are comparatively impaired in severe cases, often accompanied by intense activation or lymphopenia. Since December 2020, SARS-CoV-2 vaccines have been licensed and administered worldwide. These vaccines induce a targeted T-cell response against SARS-CoV-2. The cellular response after the third dose was strong and superior to that obtained with the second dose. COVID-19 multiple vaccines elicit a robust CD4+ and CD8+ T cell response after the short-term booster. While, the T-cell response induced by COVID-19 vaccines has been shown to decline within 6-12 months of vaccination. In addition, the long-term persistence of cellular immunity may protect against the development of severe disease. In addition, adoptive T-cell therapies have shown considerable potential in the development of COVID-19 traitement. These therapies involve the transfer of T cells with specific antiviral properties into patients to boost their immune response against SARS-CoV-2.