[Immune complexes and effector cell activation (author's transl)].

The study of antibody-dependent cellular cytoxicity mechanisms in human and experimental schistosomiasis has revealed the particular role of immune complexes in triggering phagocytic cell activation. IgE complexes or aggregates were demonstrated to bind to specific receptors on rat macrophages as well as on human or baboon macrophages, leading to the killing of the parasite target. In the eosinophil-dependent cytotoxicity mechanisms, IgE complexes have been shown to exert a regulatory effect on eosinophil activation in vitro and in vivo and on the ability of this cell population to kill parasites. The various observations reported in this review suggest that the characteristics of the Fc receptors, the composition and antigen-antibody ratio of immune complexes might be essential factors in the regulation of the immune response against parasites.