How do T-cells contribute to the immune response?

T-cells play a crucial role in the immune response by directly attacking infected cells. They are a type of lymphocyte that is essential for the adaptive immune system. When T-cells encounter cells that display foreign antigens, such as those found on the surfaces of virus-infected or cancerous cells, they become activated and can carry out several functions. One key function is the cytotoxic action, where certain subtypes of T-cells, known as cytotoxic T-lymphocytes, actively seek out and destroy these infected or aberrant cells. This mechanism is vital for controlling and eliminating infections as well as for tumor surveillance.

In contrast, other components of the immune system, like B-cells, are responsible for producing antibodies, which help neutralize pathogens rather than directly engaging in cell destruction. Barriers against pathogens are typically formed by physical structures like skin and mucous membranes, not by T-cells. Digesting pathogens largely falls under the activity of phagocytes, such as macrophages and neutrophils, which engulf and break down microorganisms. Understanding the specialized roles of T-cells enhances our grasp of how the immune system coordinates its response to various challenges.