Neutrophils as effector cells for antibody-based immunotherapy of cancer.

The use of monoclonal antibodies (mAbs) has become a mainstream strategy for the treatment of cancer. After binding to the target antigen, they mediate a plethora of effector functions for elimination of tumour cells. These range from direct effects like induction of apoptosis or growth inhibition of tumour cells to activation of immune system components, including the initiation of complement-dependent lysis or recruitment of immune effector cells. Neutrophils are generally not considered as potential effector cells. However, the most abundant population of circulating white blood cells consists of neutrophils, which express Fc receptors for both immunoglobulin (Ig) G and IgA. In the presence of mAbs that are directed against tumour cells, they execute potent cytotoxic functions. Moreover, as they play a role in regulating adaptive immunity, neutrophil activation may lead to the generation of anti-tumour immune responses as well. This article addresses the possibility of exploiting neutrophils for mAb-based immunotherapy of cancer.