Suppression of IgE Antibody Production by Component of Vibrio Cholerae

We have reported that IgE antibody production was enhanced by sensitization with vibrio cholerae whole cell or a component of vibrio cholerae IF52. We designed to find out factors which suppress the IgE antibody production. Mice were sensitized intraperitoneally with IF30, IF52 or vibrio cells before or after the immunization. IgE antibody production by DNP-vibrio cholerae was suppressed when sensitized intraperitoneally with IF30, but IgM antibody production was suppressed by sensitization with IF30 before immunization. Vibriocidal antibody production was enhanced by sensitization with IF30. IgE antibody production by DNP-ovalbumin was suppressed by sensitization of IF30, but IgM antibody production was enhanced and IgE antibody production was not affected. Non-specific IgE antibody production was enhanced by sensitization with IF52. Another study was designed to check the combined effect of oral and intraperitoneal sensitizations. Mice were first sensitized orally with IF30 or killed vibrios and were sensitized intraperitoneally with either IF30 or killed vibrios, then mice were immunized with DNP-vibrios. This sensitization method suppressed IgE antibody production stronger than one intraperitoneal sensitization with IF30, enhanced IgM antibody production, did not affect IgG antibody production and enhanced vibriocidal antibody production. Therefore, combination of the oral and systemic sensitization will be the best method for the induction of the protective immunity for cholera.