T Cell Subsets and COVID-19: Function and Dysregulation Effect

By: Chikondi Malamba-Banda, Chisomo Kafamau, Tiyamike Nthandira, Austine Kumwenda, David T. Mzinza, Gama P. Bandawe, Wilson L. Mandala,

Abstract

T cell responses are an important component of the human immune response to viral infections and specifically for viral clearance, establishing memory recall and inducing antibody responses. In SARS-CoV-2 infected individuals, lymphopenia and/or T-cell exhaustion somehow contributes towards the development of severe diseases. In contrast, long-lived memory T cells play a key role in preventing severe cases of COVID-19 disease. Exposure to SARS-CoV-2 either through infection or vaccination generates immune cells that provide long-term immunity to SARS-CoV-2 which is crucial for the development of herd immunity. In this review, we summarize what is currently known about various T cells subsets such as CD4+ and CD8+ T cells in response to SARS-CoV-2 and the specific T cell responses linked to natural, vaccine-induced and hybrid immunity highlighting the need to look beyond blood to fully understand how T cells function in the tissue. Understanding the T cell-specific immune responses in various body tissues could facilitate the formulation of better therapeutic strategies for COVID-19 patients.