antibody-dependent cellular cytotoxicity

Definition

Target type: biologicalprocess

Cytolysis of target cells by natural killer cells, eosinophils, neutrophils, monocytes, or macrophages following engagement of antibodies bound to the target cells by Fc receptors on the effector cells. [GOC:pr, ISBN:0781735149, PMID:11677095, PMID:9581795]

Antibody-dependent cellular cytotoxicity (ADCC) is a crucial immune mechanism where antibody-coated target cells are destroyed by immune effector cells, primarily natural killer (NK) cells. This process involves several steps:

1. **Antibody Binding:** Specific antibodies, usually IgG, bind to antigens on the surface of target cells, such as infected cells, cancer cells, or transplanted cells.

2. **Effector Cell Recruitment:** The Fc portion of the bound antibody interacts with Fc receptors (FcγR) on the surface of NK cells or other effector cells, like macrophages. This interaction bridges the antibody-coated target cell and the effector cell.

3. **Effector Cell Activation:** The binding of FcγR to the antibody initiates a signaling cascade within the effector cell. This activation triggers a series of downstream events, including the release of cytotoxic granules.

4. **Target Cell Lysis:** The cytotoxic granules, containing perforin and granzyme, are released by the effector cell and directed towards the target cell. Perforin forms pores in the target cell membrane, allowing granzyme to enter. Granzyme then activates apoptotic pathways within the target cell, leading to its programmed death.

5. **Immune Clearance:** The dead target cell is then cleared from the body by phagocytic cells, such as macrophages.

ADCC is a vital defense mechanism against a wide range of pathogens and cancerous cells. It plays a crucial role in immune surveillance and the elimination of infected or abnormal cells. The effectiveness of ADCC is influenced by various factors, including the type of antibody involved, the expression of target antigens, and the activation state of the effector cells.'
"

Proteins (1)

Compounds (2)