Journal of Clinical and Cellular Immunology
Open Access

Abstract

Induction of Protective Cellular and Humoral Responses against Fasciolosis in Rabbits using Immunoaffinity Fraction of Fasciola gigantica Excretory Secretory Products

Sanaa KA Abou-El-Doubal, Soad E Hassan, Nagwa I Toaleb, Ahmed G Hegazi and Eman H Abdel-Rahman

Fasciolosis due to Fasciola gigantica or F. hepatica causes significant production losses in animals, as well as being a zoonotic disease of global importance. In an attempt to develop vaccine against fasciolosis in rabbits, an immunoaffinity fraction of F. gigantica excretory secretory products was isolated. The fraction possesses 87.67% of the initial antigenic activities with 2051.5 fold increase in specific activity compared to crude extract. It consists of two bands of molecular weight 27 kDa and 23.5 kDa as revealed by SDS-PAGE. The detailed structural analyses of the pure fraction showed O-glycan [Ser-Arg-Ser-Arg-Ser-GlucNAc] using mass spectrometry. Vaccination of rabbits twice with the fraction resulted in 85% reduction in worm burden. It is also resulted in high antibody IgG levels as proved by ELISA. The highest IgG response was observed in vaccinated rabbits at two weeks post infection and remained stable to the end of the experiment. A significant expression of IL-4 and INF-γ was observed in vaccinated rabbits starting one week until thirteen weeks post infection. The level of IL-4 was significantly higher than the level of INF- γ throughout the experiment as measured by ELISA. Collectively, the current results suggest promising immunoprophylactic potentials of the immunoaffinity fraction of Fasciola gigantica excretory secretory products against fasciolosis in rabbits through induction of both cellular and humoral responses.