title: Role of the antibody Fc in the immune clearance of Trypanosoma cruzi.
abstract: Passive transfer of immune serum obtained from mice chronically infected with Trypanosoma cruzi to mice containing circulating bloodstream trypomastigotes induces a very fast clearance of the parasites. Comparison of trypomastigotes clearance in normocomplementemic and C5-deficient mice showed no difference. IgG fraction obtained from immune serum was very efficient at inducing complement-mediated lysis and immune clearance of bloodstream trypomastigotes, whereas its Fc-missing F (ab') 2 fragments, although able to induce lysis, were unable to induce clearance. It is suggested that the immune clearance of bloodstream trypomastigotes is dependent on the antibody Fc region and that complement-mediated lysis is not a prerequisite for elimination of the parasites from circulation.
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D014355:Chagas Disease / Q000276:immunology* / Q000628:therapy; D003182:Complement C5 / Q000172:deficiency; D005260:Female; D007117:Immunization, Secondary; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007141:Immunoglobulin Fc Fragments / Q000276:immunology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D000913:Antibodies, Protozoan; D003182:Complement C5; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments