Relational interaction between T-lymphocytes and SARS-CoV-2: A review.

Coronavirus disease 2019 (COVID-19) has turned out as one of the worst medical and economic misfortunes across the globe. The etiological agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a member of the Coronaviridae family and represents a disease manifestation from asymptomatic to severe respiratory damage. High transmissibility and contagious nature of the virus helps it to flourish in a large population. The immune system aids to retain the virus, but with accelerated cytokine secretion, it could transform into double edge sword resulting in unrestrained systemic inflammation which might become life-threatening. SARS-CoV-2 sets substantial impact on T-lymphocytes during its course of infection. The number of CD4+ T, CD8+ T, and Treg cells tend to decrease profoundly in case of severe illness. Besides, the virus modulates the CD4+ T/ CD8+ T and Treg/Th17 cells ratio and induces the functional exhaustion of T cells to make them inefficient. T cells define the pathogenesis of severe cases and provide major contributions in antiviral defense. Therefore, the apprehension of T-lymphocytes in SARS-CoV-2 infection would implicate in developing antivirals, disease control, and would broaden the way for vaccine formulation. Thus, the review depicts the significance of T-lymphocytes interaction with SARS-CoV-2. Keywords: SARS-CoV-2; COVID-19; T-lymphocytes; cytokine; inflammation; immune response.