What type of immunity are T lymphocytes responsible for?

T lymphocytes, also known as T cells, play a crucial role in the immune response, specifically in cell-mediated immunity. This form of immunity involves the activation and proliferation of T cells in response to antigens, typically from intracellular pathogens, such as viruses and some bacteria. T cells do not produce antibodies; instead, they directly kill infected cells or help other immune cells respond to the infection. This process is vital for controlling and eliminating infections, particularly those that cannot be effectively managed by antibodies alone.

Cell-mediated immunity contrasts with humoral immunity, which is primarily carried out by B lymphocytes that produce antibodies against extracellular pathogens. T cells also contribute to adaptive immunity, which encompasses both humoral and cell-mediated responses. However, the direct mechanism by which T lymphocytes function is specifically categorized under cell-mediated immunity, as it is characterized by the actions taken by T cells to combat infections at the cellular level.

This specialized role underscores the importance of T lymphocytes in the immune system and how they specifically target and eliminate infected or malfunctioning cells, forming one of the key pillars of the body's defense mechanisms.