What is the main role of cytotoxic T cells?

Cytotoxic T cells, also known as CD8+ T cells, play a critical role in the immune response by directly killing infected host cells. Their primary function involves recognizing cells that have been compromised by viral infections or intracellular bacteria. Once these infected cells present specific antigens on their surface, cytotoxic T cells bind to these antigens via their T cell receptors.

Upon binding, cytotoxic T cells release perforin and granzymes, which are molecules that create pores in the target cell's membrane and induce apoptosis, or programmed cell death. This process is essential for containing infections and eliminating compromised cells, thereby preventing the spread of pathogens within the body.

Understanding the role of cytotoxic T cells emphasizes the cellular aspect of the adaptive immune response, where different immune cells have specialized functions tailored to combat various threats. This knowledge is foundational for comprehending how the immune system operates and how it can be harnessed in vaccines and immunotherapies.