On-line version ISSN 1025-0298
PEREZ, José Luis et al. Obtaining Vibrio cholerae 01 outer membrane extracts with different detergents. Vaccimonitor [online]. 2006, vol.15, n.1, pp. 1-7. ISSN 1025-0298.
Two oral vaccine variants have been developed to prevent cholera infection: one from genetically attenuated strains, and the other one from inactivated whole cells. A subunit vaccine could be another very attractive alternative. In this report, we describe the partial purification and preliminary characterization of V. cholerae O1 Outer Membrane Protein-Lipopolysaccharide (OMP-LPS) complexes, to select a proteoliposome that could be administered orally in humans as a cochleate. Preparations were obtained using different detergents. The quantity of LPS was estimated by determination of endotoxic units using Limulus test (LAL). The composition of the samples was visualized by SDS-PAGE and dot blot assay. Balb/c mice were inoculated intranasally (IN) and the immune response was evaluated using ELISA and vibriocidal antibody titer assay. The molecular size of the preparation giving the best results for immunogenicity assays was estimated by chromatography on Sephacryl S- 1000. Different electrophoretic profiles were obtained according to the type of detergent used. LPS was identified in all the preparations evaluated. The preparation obtained with 15% SDS showed the lowest OMP/LPS relation, the best results for the immunogenicity assay and a similar molecular size when compared to VA-MENGOC-BC proteoliposome. These results are very stimulating and constitute a very important step for research to obtain a subunit vaccine as a preventive alternative against cholera.
Keywords : Cholera; vaccines; vibriocidal response; OMP-LPS complexs.