Infection of congenitally athymic (nude) mice with Toxoplasma gondii.

Nude mice, congenitally lacking most thymus-derived lymphocytes, are neither more susceptible nor more resistant against primary infection with virulent T. gondii cells than normal control mice. Both mouse groups died at the same time after intraperitoneal infection. Treatment with sulfadiazine protected both mouse groups against acute fatal disease. After termination of treatment with sulfadiazine the Nude mice gradually died, whereas the normal hairy mice survived. The latter had developed high amounts of antibodies and protective immunity to an otherwise lethal challenge infection. In the serum of Nude mice no antibodies could be detected. Pathologic alterations existed in the livers of Nude mice at the time of death.