Immunity to Babesia in mice. III. The effects of corticosteroids and anti-thymocyte serum on mice immune to Babesia rodhaini.
BALB/c mice, immunized against Babesia rodhaini by an amicarbalide controlled infection, were exposed to selective immunosuppressive treatment with corticosteroids and anti-thymocyte serum (ATS) respectively. Hydrocortisone acetate, 100 mg/kg, given i.p. six times during the three weeks after challenge inoculation caused a rising parasitaemia and high mortality (6/7). Dexamethasone in the drinking water at 20 mg/l or 10 mg/l for 22 days had a similar suppressive effect on the protection against B. rodhaini. Mortality, 100% at the dose rate of 20 mg/l and 50% at 10 mg/l, occurred both in challenged and in carrier animals after the reappearance of parasites in the bloodstream. All the ATS-treated immune mice demonstrated parasitaemia after challenge, although at a lower level than did the corticosteroid treated mice. Seven out of 9 animals died. Corticosteroid-sensitive macrophages together with T-lymphocytes are considered to play an important role in protection against B. rodhaini in specifically induced immunity in mice.
D000818:Animals; D000961:Antilymphocyte Serum / Q000494:pharmacology*; D001404:Babesiosis / Q000276:immunology*; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D006854:Hydrocortisone / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000276:immunology*
D000961:Antilymphocyte Serum; D005938:Glucocorticoids; D003907:Dexamethasone; D006854:Hydrocortisone