Perforin

Definition

Perforin is a protein released by cytotoxic T cells and natural killer (NK) cells that forms pores in the membranes of target cells, leading to cell lysis. It plays a critical role in the immune system's ability to eliminate infected or cancerous cells.

5 Must Know Facts For Your Next Test

1. Perforin is essential for the function of cytotoxic T cells and NK cells.
2. It forms pores in the target cell membranes, allowing granzymes to enter and induce apoptosis.
3. Mutations in the perforin gene can lead to immunodeficiency and increased susceptibility to infections.
4. Perforin-mediated cytotoxicity is crucial for controlling viral infections and cancer.
5. It works in concert with other molecules like granzymes to ensure effective immune responses.

Review Questions

• What types of immune cells release perforin?
• How does perforin contribute to the destruction of target cells?
• Why are mutations in the perforin gene significant?

Related terms

Cytotoxic T Cells: A type of immune cell that kills cancer cells, virus-infected cells, and damaged cells.

Natural Killer (NK) Cells: Immune cells that can attack and destroy tumor cells or pathogen-infected cells without prior sensitization.

Granzymes: Serine proteases released by cytotoxic T cells and NK cells that induce apoptosis in target cells after being delivered through perforin-formed pores.