The interactions of therapeutic antibodies with Fc receptors

During the last two decades, a rapidly increasing number of therapeutic antibodies have been generated and used in a variety of diseases. The rationale of passive immunotherapy is that, due to their unique specificity, antibodies can selectively target and act on molecules associated with pathological processes. However, how therapeutic antibodies actually act on target molecules and cells under specific conditions is poorly known. As a consequence, whether the efficacy of available antibodies could be increased and whether new antibodies could be tailored for specific purposes have not been thoroughly investigated. We discuss in this review how therapeutic antibodies interact with Fc receptors, what are the cellular responses induced by these interactions and how a better knowledge of these interactions and biological responses could improve antibody-based passive immunotherapy.