T cell

In Context

• The study reveals the durability and robustness of the T cell responses against variants, including Delta, even after one year of infection. 
  • Strong and long standing T cell responses were seen even when people were not reinfected or vaccinated

About T cell

• T cells are a diverse and important group of lymphocytes that mature and undergo positive and negative selection processes in the thymus. 
• Types: 
  • There are several types of T cells; the most common and well-known are the CD4+ T cells (helper T cells) and CD8+ T Cells (cytotoxic T cells, or killer T cells).
  • As the names suggest, helper T cells ‘help’ other cells of the immune system, whilst cytotoxic T cells kill virally infected cells and tumours.
• Functions:
  • T cells play a vital role in both components of active immunity, including cell-mediated and to some extent humoral immunity. 
  •  T cells cannot recognize soluble, free antigens. T cells can only recognize protein-based, receptor-bound antigens. 

Source:TH