Effect of cyclophosphamide on Toxoplasma gondii infection: reversal of the effect by passive immunization.
Treatment of mice with cyclophosphamide (CY) at a dose of 250 mg/kg body weight 24 hr prior to infection with an avirulent strain of Toxoplasma gondii delays the appearance of antibody by about one week and results in 70% mortality. To discount other effects of CY besides inhibition of antibody synthesis, CY-treated infected mice were passively immunized with a pooled specific serum collected from chronically infected syngeneic animals. Passive immunization reversed the effect of CY treatment if the titre of antibody in recipients reached 1 : 512 or more, as measured by the indirect immunofluorescence technique (IFT). It is therefore suggested that antibody plays an important role in establishing an infection-immunity (premunition) in this system.
D000818:Animals; D000906:Antibodies / Q000032:analysis; D000917:Antibody Formation / Q000187:drug effects*; D003520:Cyclophosphamide / Q000494:pharmacology*; D005260:Female; D007116:Immunization, Passive; D008297:Male; D051379:Mice; D014124:Toxoplasmosis, Animal / Q000276:immunology*
D000906:Antibodies; D003520:Cyclophosphamide