Cytotoxic T cells

Definition

Cytotoxic T cells are a subtype of T lymphocytes that directly kill infected, cancerous, or otherwise abnormal cells. They recognize antigens presented by MHC class I molecules on the surface of target cells.

5 Must Know Facts For Your Next Test

1. Cytotoxic T cells express CD8 receptors, which bind to MHC class I molecules.
2. They release perforin and granzymes to induce apoptosis in target cells.
3. Activation requires antigen presentation by an antigen-presenting cell (APC) and co-stimulatory signals.
4. They play a crucial role in controlling viral infections and tumor surveillance.
5. Memory cytotoxic T cells provide a faster response upon re-exposure to the same antigen.

Review Questions

• What type of MHC molecule do cytotoxic T cells interact with?
• Which molecules do cytotoxic T cells release to induce apoptosis in infected cells?
• What is the role of memory cytotoxic T cells?

Related terms

Helper T Cells:

A subtype of T lymphocytes that assist other white blood cells in immunologic processes.

MHC Class I: Molecules found on all nucleated cells that present endogenous antigens to cytotoxic T cells.

Perforin:

A protein released by cytotoxic T cells that forms pores in the membrane of target cells.