Antibody-dependent cell-mediated cytotoxicity

Antibody-dependent cell-mediated cytotoxicity (ADCC) (pronunciation: An-ti-bo-dy-de-pen-dent cell-me-di-a-ted cy-to-tox-i-ci-ty) is a mechanism of immune response in which the immune system's cells actively lyse a cell whose membrane-surface antigens have been bound by specific antibodies. It is one of the methods through which antibodies, as a part of the humoral immune response, can act to limit and contain infection.

Etymology

The term "Antibody-dependent cell-mediated cytotoxicity" is derived from its function. "Antibody-dependent" refers to the requirement of the presence of an antibody for the process to occur. "Cell-mediated" indicates that it is carried out by cells, specifically immune cells. "Cytotoxicity" is derived from the Greek words "kytos" meaning "cell" and "toxicity" meaning "poison", indicating the process involves the destruction of cells.

Mechanism

In ADCC, the antibody binds to the target cell at the antigen-specific region known as the Fab region. The Fc region of the antibody is recognized and bound by an effector cell, most commonly natural killer (NK) cells, but also macrophages and neutrophils. The effector cell then releases cytotoxic substances, such as perforin or granzymes, which leads to lysis or apoptosis of the target cell.

Related Terms

Natural Killer Cell: A type of lymphocyte that plays a major role in the host-rejection of both tumors and virally infected cells.
Antigen: A substance that induces an immune response, specifically the production of an antibody.
Antibody: A blood protein produced in response to and counteracting a specific antigen.
Immune Response: The body's defensive reaction to invasion by bacteria, viruses, or other foreign substances.
Humoral Immune Response: The aspect of immunity that is mediated by secreted antibodies produced in the cells of the B lymphocyte lineage.