Fig. 3

Exosomes and tumor immunosurveillance. Exosome reduce tumor immunosurveillance by interfering with the innate and adaptive immune system. This can cause failure of tumor immunotherapy. Exosomes reduce antibody dependent cytotoxicity by inhibiting natural killer cells. Exosomes reduce activation of the complement systems causing reduced membrane attack complex (MAC) formation and cell lysis. Both mechanism are important effector functions of therapeutic antibodies. Furthermore exosomes reduce T- and B-lymphocyte function and their differentiation from progenitor cells. Lymphocyte function is important for the vaccine effect of therapeutic antibodies