Cytotoxic t cells

Cytotoxic T cells (also known as Tc cells, Cytotoxic T lymphocytes (CTL), Killer T cells) are a type of T cell that play a key role in the immune system, particularly in the elimination of cancer cells and cells infected with viruses.

Function

Cytotoxic T cells are part of the adaptive immune system, which provides the body with tailored defenses against specific pathogens. They are activated when their T cell receptor (TCR) recognizes a specific antigen presented on the surface of target cells. This antigen is presented by a Major histocompatibility complex (MHC) molecule.

Once activated, cytotoxic T cells release cytotoxins, such as perforin and granzyme, which induce apoptosis (programmed cell death) in the infected or cancerous cell. This process is known as cell-mediated immunity.

Activation

The activation of cytotoxic T cells requires the recognition of specific antigens presented by MHC molecules on the surface of the target cell. This is often facilitated by helper T cells, which release cytokines that stimulate the cytotoxic T cell.

Role in disease

Cytotoxic T cells play a crucial role in the control and elimination of viral infections. They are also important in the immune response against certain types of cancer. However, in some cases, cytotoxic T cells can contribute to autoimmune diseases, when they mistakenly target and destroy healthy cells.

See also

• Immune system
• T cell
• Cell-mediated immunity
• Major histocompatibility complex
• Antigen
• Apoptosis