FC-GAMMA RECEPTORS IN CANCER AND INFECTIOUS-DISEASE

Through interaction with antibody, IgG Fc receptors provide an interface between specific humoral immunity and FcgammaR-bearing host cells. FcgammaR trigger such diverse functions as immune complex clearance, phagocytosis of opsonized pathogens, reactive oxygen intermediate and enzyme secretion, and antibody-dependent cellular cytotoxicity (ADCC). Moreover, FcgammaR are the exclusive trigger molecules for tumor cell killing by human myeloid cells. Studies of FcgammaR function have been aided by the use of bispecific antibodies to link cells or pathogens to specific host cell molecules, including FcgammaR. These reagents have permitted determination of the role of FcgammaR in ADCC of the protozoan, Toxoplasma gondii, by human effector cells. This approach has also indicated that FcgammaR do not serve as entry points for viruses such as dengue virus and HIV. Taken together, these results provide insight into the utility of manipulating FcgammaR function in the therapy of cancer and infectious disease.