Modified antibody clarifies tumor-killing mechanisms

The structure of an antibody was modified to selectively activate a specific pathway of the immune system, demonstrating its value in killing tumor cells.

Immunotherapy—the use of the immune system to fight disease—has made tremendous progress in the fight against cancer. Antibodies such as immunoglobulin G (IgG) can identify and attack foreign or abnormal substances, including tumor cells. But to control and amplify this response, scientists need to know more about how elements of the immune system recognize tumor cells and trigger their destruction. There are two main pathways for this: antibody-dependent mechanisms and complement-dependent mechanisms.

The antibody pathway involves coating the surfaces of tumor cells with antibodies that recruit “natural killer” (NK) cells and macrophages (a type of white blood cell) to destroy the tumor cells. The complement pathway (so named because it complements the antibody pathway) also engages NK cells and macrophages and includes a third mechanism—a cascade of events culminating in tumor-cell destruction via a membrane attack complex (MAC).

>Read more on the ALS webpage

Image: extract of a schematic illustration (see on the ALS webpage)