Activated macrophages in highly irradiated cercariae-induced immunity toSchistosoma japonicumin rats
SUMMARYThe results of studies on the schistosomulicidal activity of activated peritoneal and alveolar macrophages (pMø and aMø) from rats immunized with highly irradiated (50 krad.)Schistosoma japonicumcercariae are reported. The authors have examined the activation of these macrophages in terms of spreading, adhesion and ingestion of sheep erythrocytes and pinocytosis of horse-radish peroxidase. Using three criteria, peritoneal macrophages and alveolar macrophages from immunized rats and from rats intraperitoneally injected with BCG were significantly more active than those from normal rats or rats stimulated with 10% proteose-peptone or 1% sodium thioglycolate. A significantly higher percentage of adhesion and ingestion was obtained with the sheep erythrocytes that were co-opsonized by heat-inactivated rat anti-sheep erythrocyte serum and fresh normal rat serum. Schistosomulicidal effects were observed with macrophages from irradiated cercariae-immunized rats in two activation systems:in vitroactivation in the presence of macrophage-activating factor (MAF), andin vivoactivation by the intraperitoneal challenge with sonicated cercarial antigens.