Complement-Dependent Cytotoxicity (None)

Complement-dependent cytotoxicity (CDC) is a biological mechanism by which the immune system destroys target cells, such as bacteria, virus-infected cells, or tumor cells. This process is initiated when antibodies—primarily IgG1, IgG3, and IgM—isotypes—bind to antigens on the surface of a target cell. The Fc region of these antibodies then interacts with C1q, the first component of the classical complement pathway. This triggers a cascade that leads to the assembly of the membrane attack complex (MAC), resulting in pore formation in the cell membrane and subsequent lysis or death of the target cell.

Antibody-mediated complement activation leading to MAC formation and cell lysis