title: Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats.
abstract: Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D001491:Basophils / Q000276:immunology; D004804:Eosinophils / Q000276:immunology; D005260:Female; D007113:Immunity, Innate; D007116:Immunization, Passive; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D051381:Rats; D011916:Rats, Inbred F344; D011923:Rats, Nude; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014611:Vaccination; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D000906:Antibodies; D003189:p-Methoxy-N-methylphenethylamine