Induction of immune response against IpaD N-terminal region of Shigella dysenteriae in Guinea pigs

Shigellosis is one of the major causes of morbidity and mortality worldwide and the disease causes around millions deaths per year. Due to the increasing number of infected persons in some areas of the world, in addition to the emergence of strains resistant to multiple antibiotics, WHO has put emphasis on the need for an effective vaccine. Shigella bacteria attach to M- cells in epithelial cells through invasion factors and then cause mucosal ulceration, inflammation and bleeding. IpaD has an important role in pathogenicity of Shigella. The N-terminal region is the most significant functional fragment of IpaD. In this study, the induction of the immunity response against the N-terminal region of IpaD has been investigated. Ni-NTA column chromatography was used for purification of the N-terminal region of IpaD. Afterwards, the recombinant protein was injected to Guinea pigs for producing polyclonal antibodies. Produced antibody titers were measured by ELISA. This antibody was purified with a column of protein G and then examined by Western blot test. The result of Western blot confirmed the expression of the purified protein. High ELISA titers of antibody were observed in the serum of animals immunized with the protein. The polyclonal antibody purified with protein G column chromatography was confirmed by immunobloting test.