Serum Anti-Vibrio cholerae Immunoglobulin Isotype in BALB/c Mice Immunized With ompW-Loaded Chitosan

Background: Chitosan, a liner polysaccharide, is a biocompatible and safe material for the delivery of therapeutic proteins and antigens, particularly via mucosal systems. Objectives: In this study, the production of antibodies in response to outermembrane protein W (ompW)-loaded chitosan in BALB/c mice was evaluated. Materials and Methods: Mice were subjected to intraperitoneal injection of ompW or nasal administration of ompW-loaded chitosan on days 1, 14, and 28, and the antibodies were measured on day 42 with ELISA. Results: The titration of antibodies indicated that the nasal administration of ompW-loaded chitosan was better able to stimulate the immune response compared to intraperitoneal injections. However, the titration of total and IgG isotypes showed a significant difference between intraperitoneal and nasal immunization (P < 0.01). A significant difference was also seen in serum IgA isotypes at over 1/80 titrations, but not at lower dilutions (P < 0.01). Despite the serum antibodies, the results of lavage fluid analysis revealed that the IgG and IgA isotypes in the mice subjected to nasal immunization with ompW-loaded chitosan were significantly higher than in the other group (P < 0.01). Conclusions: Based on the preliminary results presented in this research, it is suggested that ompW-loaded chitosan could be a suitable choice for nasal application to immunize the host against Vibrio cholerae. However, more work is required to determine the efficiency of the antibodies in neutralizing the bacterial toxin or bacterial movement.