title: Immunosuppression in mouse trypanosomiasis: inhibition of secondary antibody responses is dependent on the time of antigen priming.
abstract: Trypanosoma musculi-induced immunosuppression was examined in both congenitally athymic (nude) mice and their phenotypically normal, euthymic littermates using T-independent (polyvinylpyrrolidone = PVP) and T-dependent (sheep erythrocyte = SE) antigens. T. musculi-infected nude mice had significantly diminished direct (IgM) plaque-forming cell (PFC) responses to PVP. In euthymic mice, T. musculi parasitemia significantly inhibited the direct PFC response to both PVP and SE. Trypanosoma musculi-infected euthymic mice had significantly diminished indirect (IgG) SE-specific PFC responses if priming occurred during parasitemia; however, T. musculi parasitemia did not significantly decrease indirect SE-specific PFC responses in euthymic mice if the mice were primed before infection.
mesh_terms: D000818:Animals; D000955:Antigens, T-Independent / Q000276:immunology; D006462:Hemolytic Plaque Technique; D007108:Immune Tolerance; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007156:Immunologic Memory; D051379:Mice; D008819:Mice, Nude; D011205:Povidone / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors; D014352:Trypanosomiasis / Q000276:immunology*
chemical_list: D000955:Antigens, T-Independent; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011205:Povidone