Immunogenicity of a new recombinant IpaC from Shigella dysenteriae type I in guinea pig as a vaccine candidate.

BACKGROUND Recombinant vaccine technology is one of the most developed means in controlling infectious diseases. However, an effective vaccine against Shigella is still missing. OBJECTIVE To evaluate recombinant IpaC protein of Shigella as a vaccine candidate. METHODS In this study we cloned IpaC gene into an expression vector in prokaryotic system. The protein expression was evaluated by SDS-PAGE and Western-Blotting analysis. The recombinant protein was purified using Ni-NTA affinity chromatography. Guinea pigs were immunized with the recombinant protein and the level of immunogenicity was examined by ELISA and Western blotting of IpaC. Challenge test was done through the intraoculary injection of Shigella dysenteriae (6×108 CFU/eye) and after 48 hours was scored for keratoconjunctivitis. RESULTS The results showed a remarkable level of immunogenicity in terms of antibody response and protection against keratoconjunctivitis in tested animals. The recombinant IpaC protein provided a protective system against Shigella dysenteriae type I during the challenge test. CONCLUSION The results showed the potential of using recombinant IpaC in preparation of vaccine in perspective studies.