PROTECTIVE IMMUNITY INDUCED IN MICE BY F8.1 AND F8.2 ANTIGENS PURIFIED FROM SCHISTOSOMA-MANSONI EGGS

Schistosoma mansoni soluble egg antigens (SEA) were fractionated by is oelectric focusing, resulting ii? 20 components, characterized by pH, absorbance and protein concentration. The higher absorbance fractions were submitted to electrophoresis, and fraction 8 (F8) presented a spe cific pattern of bands on its isoelectric point. Protein 3 was observe d only on FS, and so, it was utilized to rabbit immunization, in order to evaluate its capacity of inducing, protective immunity IgG antibod ies from rabbit anti-F8 serum were coupled to Sepharose, and used to o btain the specific antigen by affinity chromatography. This antigen, s ubmitted to electrophoresis, presented two proteic bands (F8.1 and F8. 2), which were transferred to nitrocellulose membrane (PVDF) and seque nciated The homology of F8.2 to known proteins was determined using th e Basic Local Alignment Search Tool program (BLASTp). Significant homo logies were obtained for the rabbit cytosolic Ca2+ uptake inhibitor; a nd for the bird a(1)-proteinase inhibitor: immunization of mice with F 8.1 and F8.2, in the presence of Corynebacterium parvum and AI(OH)(3) as adjuvant, induced a significant protection degree against challenge infection, as observed by the decrease on worm burden recovered from portal system.