Fasciola gigantica: immunization of rabbits with proteins isolated from coproantigen.

Two fractions were isolated from coproantigen by ion-exchange chromatography in which DEAE cellulose was utilized. Both fractions and crude antigen were characterized by SDS-polyacrylamide gel electrophoresis which revealed 13 bands of molecular weight ranged from 205-31 in crude coproantigen. While fraction I resolved into six bands of molecular weight 198, 178, 148, 111, 101 & 45. Fraction II showed seven bands of 191 KDa, 178KDa, 166KDa, 118KDa, 98.5KDa, 72KDa & 32KDa. Fraction 1I was higher immunoreactivity than fraction by ELISA. Three immunoreactive bands of 191KDa, 118KDa & 98.5KDa were identified in fraction II using immunoblot assay. Five bands of 178KDa, 148KDa, 111KDa, 101KDa & 45KDa were detected in fraction I. Immunization of rabbits twice with fraction II in Freund's adjuvant with two weeks interval followed by challenge with F. gigantica metacercariae resulted in 66.6% protection from infection. The protection was assessed by detect-ion of hepatic damage, worm recoveries and antibody response. High level of IgG response in vaccinated rabbits than control infected ones occurred and being responsible for the recorded protection.