Open AccessOuter membrane vesicles of S higella boydii type 4 induce passive immunity in neonatal mice
Author(s) -
Mitra Soma,
Barman Soumik,
Nag Dhrubajyoti,
Sinha Ritam,
Saha Dhira Rani,
Koley Hemanta
Publication year - 2012
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2012.01004.x
Subject(s) - shigella , shigellosis , shigella flexneri , shigella dysenteriae , shigella boydii , microbiology and biotechnology , biology , immunogen , shigella sonnei , bacterial outer membrane , virology , salmonella , immunology , antibody , bacteria , escherichia coli , biochemistry , genetics , gene , monoclonal antibody
Like most other G ram‐negative bacteria, S higella releases outer membrane vesicles ( OMV s) into the surrounding environment during growth. In this study, we have exploited OMV s of S higella as a protective immunogen in a mice model against S higellosis . Distinctive vesicle secretion was noticed from different S higella strains. Among them, S higella boydii type 4 ( BCH 612) was secreting relatively higher amounts. We immunized female adult mice orally with 32 μg of purified S higella boydii type 4 ( BCH 612) OMV s four times at 1‐week intervals. Antibodies against these vesicles were detected in immunized sera until 120 days, indicating a persistent immune response. To observe whether the passive immunity had been transferred to the neonates, the immunized female mice were mated and the offspring were challenged orally, with wild‐type homologous and heterologous S higella strains. All offspring of immunized mothers survived the challenge with homologous strain BCH 612 and up to 81% protective efficacy was noted against heterologous strains S higella dysenteriae 1, S higella flexneri 2a, S higella flexneri 3a, S higella flexneri 6 and S higella sonnei . Our results exhibited for the first time that oral immunization of adult female mice with purified OMV s of S higella , without any adjuvant, conferred passive protection to their offspring against shigellosis. These findings will contribute to the future development of a potential non‐living vaccine candidate against shigellosis.