- Antibody-Dependent Cellular Cytotoxicity (ADCC) is a crucial immune mechanism that bridges humoral and cellular immunity. In this process, antibodies mark infected or malignant cells for destruction by immune effector cells. These effector cells, primarily natural killer (NK) cells, macrophages, neutrophils, and eosinophils, recognize antibody-coated targets through their Fc receptors.
- The process begins when antibodies (mainly IgG) bind to specific antigens on target cells. The Fc portion of these antibodies is then recognized by Fc receptors on effector cells, particularly FcγRIII (CD16) on NK cells. Upon activation, these cells release cytotoxic granules containing perforin and granzymes, which induce programmed cell death in the target cells.
- ADCC plays a vital role in both natural immunity and therapeutic interventions. Modern cancer treatments like rituximab and trastuzumab harness this mechanism to destroy tumor cells.
- The effectiveness of ADCC depends on factors such as antigen density, antibody affinity, and Fc receptor expression on effector cells.
- Beyond cancer treatment, ADCC is crucial in fighting viral infections. However, some viruses can evade this response by downregulating Fc receptors or producing decoy proteins. Understanding these evasion strategies is essential for developing better vaccines and antiviral therapies.
- Research continues to optimize ADCC-based therapies through antibody engineering and the development of enhanced effector cells. While ADCC offers powerful therapeutic potential, it must be carefully controlled, as it can contribute to autoimmune responses if antibodies mistakenly target healthy cells.
