What role do T-cells play in the immune system?

T-cells are a crucial component of the adaptive immune response, and one of their primary functions is to directly attack and destroy infected or cancerous cells. This activity is carried out primarily by cytotoxic T-cells, which recognize specific antigens presented on the surface of infected or abnormal cells. Upon recognition, these T-cells release perforins and granzymes, substances that create pores in the target cell's membrane and induce apoptosis (programmed cell death).

This direct attack is vital for controlling infections caused by intracellular pathogens, such as viruses, as well as for eliminating cancer cells that may express abnormal antigens. While T-cells also have other roles in the immune system, such as helping B-cells in antibody production and enhancing phagocytic activity, their direct attack on pathogens is a defining characteristic that underscores their critical function in cellular immunity.

The other roles of T-cells, such as assisting in antibody production and enhancing phagocyte activities, highlight their importance in coordinating the immune response rather than serving as the primary mechanism of pathogen destruction.