The Immunotherapy group of Jeanette Leusen studies the working mechanisms of therapeutic antibodies and the biology of Fc receptors. As therapy for cancer, monoclonal antibodies are used that specifically target tumor cells. In the clinic, an antibody called rituximab is used for patients with non-hodgkin's lymphoma, trastuzumab for treatment of certain breast cancers, and cetuximab for metastatic colorectal cancer. Although clinical results are promising, therapeutic responses to antibody therapy remain heterogeneous, and warrant further investigation.
Previous work showed clinical responses induced by cancer therapeutic antibodies to critically depend on immune cell Fc receptors, that bind the constant part of antibodies. Fc receptors are expressed on immune cells and induce phagocytosis, cellular cytotoxicity and facilitate antigen presentation: in mice lacking Fc receptors, cancer therapeutic antibodies lose their effect on tumor growth, and in cancer patients FcR polymorphisms directly impact therapeutic responses to antibodies like rituximab.
At present, the immunotherapy group investigates the underlying mechanisms of Fc-mediated therapeutic antibody function on two levels: 1) signaling required from Fc receptors 'outside-in' killer immune cells, and 2) 'inside-out' control of Fc receptors. Furthermore, the immunotherapy group studies IgA as a next generation therapeutic antibody, for cancer but also for viral targets, such as RSV and influenza.