Efficiency Evaluation of Immunization Protocol with Echinococcus Granulosus Antigen B (Agb)

Abstract

Antigen B (AgB), the major antigens of Echinococcus granulosus, is a polymeric thermostable lipoprotein that constitutes as much as 10% of hydatid fluid.Antibody and cytokine response were both studied in rabbits immunized with Echinococcus granulosus antigen B (AgB). This study aimed to assess the effect of antigen B (AgB) on immune response for this purpose hydatid cysts were collected from liver of infected sheep from slaughter house in Basra . AgB was purified from hydatid fluid by anion exchange chromatography.For evaluation of AgB efficiency in immunization , 15 rabbits were enrolled in the study ,10 of them were immunized subcutaneously with AgB using freund's complete adjuvant after two weeks three booster injections were repeated intramuscularly according to immunization schedule using freund's incomplete adjuvant and 5 rabbits were treated as a control group. After six weeks , blood were collected from rabbits and the levels of IgG , IFN-γ and IL-10 were measured by ELISA test.Means of IgG of immunized rabbits were significantly (P < 0.05) elevated (45.9) ng/ml in comparison with control rabbits (16.6) ng/ml. Cytokines levels of Th1 (IFN-γ) and Th2 (IL-10) were recorded a significant differences (P < 0.05) between immunized and control groups , the mean concentrations of IFN-γ in immunized rabbits (28.6 pg/ml) was lower than those of control group (83.6 pg/ml) while IL-10 mean concentrations in immunized rabbits (60.1) pg/ml was higher than those of control group (18.8) pg/ml .The results indicated that AgB has the ability to modulate immune response toward Th2 bias in immunized rabbits as there was significant elevation in total IgG, IL-10 and significant decreasing IFN-γ concentration.