Evaluation of antibody responses to outer membrane vesicles (OMVs) and killed whole cell of Vibrio cholerae O1 El Tor in immunized mice

• Published in: Iranian journal of microbiology Vol. 11; no. 3; pp. 212 - 219
• Main Authors: Sedaghat, Manijeh, Siadat, Seyed Davar, Mirabzadeh, Esmat, Keramati, Malihe, Vaziri, Farzam, Shafiei, Morvarid, Shahcheraghi, Fereshteh
• Format: Journal Article
• Language: English
• Published: Iran Tehran University of Medical Sciences 01.06.2019
• Subjects: Dukoral vaccine; Killed whole cell; Original; Outer membrane vesicle; Vibrio cholerae O1 El Tor; Outer membrane vesicle; Dukoral vaccine; Killed whole cell; Vibrio cholerae O1 El Tor
• ISSN: 2008-3289; 2008-4447
• DOI: 10.18502/ijm.v11i3.1317

Cholera disease remains an important global health problem affecting 3-5 million subjects worldwide. Outer membrane vesicles (OMVs) have been found in a variety of Gram-negative bacteria and act as protective transport vesicles. The aim of this study was to evaluate Immune responses against O1 El Tor clinical strain OMV and compare it with killed whole cell (KWC), complex of (KWC-OMV) as well as the internationally licensed oral cholera vaccine, Dukoral, in serum and intestinal secretions of mice. OMVs were prepared by using modified detergent-centrifugation procedure from O1 El Tor clinical strain from 2005 outbreak. The ultrastructure and content of OMVs were investigated via the Scanning Electron Microscopy (SEM) and SDS-PAGE analysis. Three doses of oral immunization were adjusted and total IgG and IgA in serum and intestinal secretion were measured by enzyme-linked immunosorbent assay (ELISA). Extracted OMVs from the were spherical vesicles with a size ranging from 10 to 300 nm. OMV-immunized mice showed an increased level of total IgG and IgA both in serum and intestinal secretion when compared to the negative controls. Also, there existed a higher level of secretory IgA than the total IgG, suggesting the most of protection against colonization provided by sIgA. Our findings revealed that oral immunization with OMVs might induce a long-term immunity, especially when administered in combination with KWC. This study tested the adjuvant activity of OMVs and may be useful in future nano vaccine research.