Antibody-Dependent Cell-mediated Cytotoxicity (ADCC) is a sophisticated defense mechanism within the immune system. This process involves specialized antibodies and immune cells working together to identify and eliminate undesirable cells. ADCC is a vital aspect of the body’s continuous surveillance, contributing to overall health and protection.
What is an ADCC Antibody?
An ADCC antibody is not a distinct type, but describes a function certain antibodies perform. Antibodies are Y-shaped proteins produced by the immune system that recognize and neutralize foreign invaders or abnormal cells. For ADCC, immunoglobulin G (IgG) antibodies are key players.
The structure of these antibodies is crucial for ADCC function. The two “arms” (Fab regions) recognize and bind to antigens on a target cell’s surface. Once bound, the “tail” (Fc region) becomes exposed. This Fc region signals the target cell for destruction by immune cells.
How ADCC Works
ADCC begins when an antibody attaches its Fab regions to antigens on a target cell, such as an infected or cancer cell. This binding tags the target cell for elimination. The exposed Fc region is a recognition site for immune cells.
Natural Killer (NK) cells mediate ADCC. These NK cells have specialized receptors, particularly CD16, that bind to the Fc region of the antibody. This binding triggers NK cell activation. Upon activation, NK cells release cytotoxic substances, including perforin and granzymes. Perforin creates pores in the target cell’s membrane, allowing granzymes to enter and initiate cell destruction.
ADCC in Natural Immunity
ADCC plays a significant role in the body’s natural immune defense. This mechanism identifies and eliminates cells that might otherwise evade detection. For example, ADCC helps combat virus-infected cells by targeting viral proteins.
It also contributes to the clearance of bacterial infections and removing early-stage cancer cells. ADCC helps maintain cellular health and prevent disease progression by destroying abnormal or infected cells.
ADCC in Medical Treatments
Understanding ADCC has led to innovative medical treatments, particularly in cancer therapy. Scientists design specialized monoclonal antibodies to target markers on diseased cells. When these antibodies bind to cancer cells, they activate the body’s ADCC mechanism.
This activation recruits immune cells, primarily NK cells, to the tumor site. These antibodies harness the patient’s immune system to attack cancerous cells while minimizing harm to healthy tissues. Therapeutic antibodies leveraging ADCC are used in treating various cancers, demonstrating how leveraging ADCC has transformed approaches to targeted therapies.