title: Suppressive effect of secondary Toxoplasma gondii infection on antibody responses in mice.
abstract: The effect of the secondary infection with Toxoplasma gondii on antibody responses to unrelated antigens was examined in mice. A reinfection with 5 X 10(3) organisms did not affect either primary anti-sheep erythrocyte antibody responses, or anti-dinitrophenol antibody responses to dinitrophenylated keyhole limpet hemocyanin. With an increase of the reinfection dose to 2.5 X 10(4) organisms, suppression of anti-sheep erythrocyte antibody responses was induced. By contrast, in the primary infection, the anti-sheep erythrocyte and anti-dinitrophenol antibody responses were markedly suppressed by an injection with only 5 X 10(2) or 1 X 10(3) T. gondii organisms. Plastic-adherent cells of spleens from mice reinfected with 2.5 X 10(4) organisms showed a strong suppressor activity in an in vitro primary anti-sheep erythrocyte antibody response system. These results demonstrate that a nonspecific suppression of antibody responses is provoked by a secondary T. gondii infection, only when mice receive a large number of organisms in the reinfection, and the suppressed antibody responses seem to be caused by an activation of suppressor cells that adhere to plastic.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: A
authors.initials: A
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000917:Antibody Formation; D004136:Dinitrobenzenes / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D007108:Immune Tolerance; D007114:Immunization; D051379:Mice; D008810:Mice, Inbred C57BL; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D014124:Toxoplasmosis, Animal / Q000276:immunology*
chemical_list: D004136:Dinitrobenzenes