Immunization with Vibrio cholerae outer membrane vesicles induces protective immunity in mice

Area of Science:

• Immunology
• Microbiology
• Vaccinology

Background:

• Vibrio cholerae, a gram-negative bacterium, releases outer membrane vesicles (OMVs) during growth.
• OMVs contain various antigens that can potentially elicit immune responses.

Purpose of the Study:

• To evaluate the immunogenicity and protective efficacy of V. cholerae-derived OMVs in a mouse model.
• To investigate the impact of different immunization routes (intranasal, intragastric, intraperitoneal) on immune responses and protection.

Main Methods:

• Female mice were immunized via intranasal, intragastric, or intraperitoneal routes with purified V. cholerae OMVs.
• Immune responses, including immunoglobulin titers and specific isotypes, were analyzed.
• Offspring of immunized mice were challenged orally with V. cholerae to assess protection.

Main Results:

• All immunization routes induced high-titer, long-lasting immune responses against OMV antigens.
• Mucosal immunization (intranasal and intragastric) specifically induced significant levels of Immunoglobulin A.
• Offspring of immunized mice were protected against V. cholerae colonization regardless of the maternal immunization route.

Conclusions:

• Mucosal immunization with V. cholerae OMVs induces robust, long-term protective immunity against cholera in offspring.
• OMV-based vaccines, administered via oral or intranasal routes, represent a potential strategy for developing nonliving vaccines against V. cholerae and other enteric pathogens.