• Vaccine Name: MBP fused on Campylobacter FlaA (MBP-FlaA)
• Target Pathogen: Campylobacter jejuni
• Target Disease: Campylobacterosis
• Vaccine Ontology ID: VO_0004101
• Type: Conjugate vaccine
• Antigen: recombinant protein comprising the maltose-binding protein (MBP) of E. coli fused to amino acids 5 to 337 of the FlaA flagellin of Campylobacter coli VC167 (Lee et al., 1999)
• FlaA from C. jejuni NCTC 11168 gene engineering:
  • Type: flagellin protein
  • Description:
  • Detailed Gene Information: Click Here.
• Adjuvant:
  • Adjuvant name:
  • VO adjuvant ID: VO_0001321
  • Description: immunization occurs with the mutant E. coli heat-labile enterotoxin (LT( R192G)) as a mucosal adjuvant (Lee et al., 1999)
• Preparation: Part of the flaA gene ( 780 base pairs ) was cloned in plasmid pBEB downstream and in frame with the LT-B to allow expression of a hybrid protein . Transformed E coli chi 6097 expressed the hybrid protein ( 43 kdaltons ) in inclusion bodies at mid log phase . The inclusion bodies were isolated , and the identity of the protein was verified by western blot . (Khoury et al., 1995)
• Virulence: The full range of MBP-FlaA doses were effective in eliciting antigen-specific serum IgG responses, and these responses were enhanced by adjuvant use. Stimulation of FlaA-specific intestinal secretory IgA (sIgA) responses required immunization with higher doses of MBP-FlaA or coadministration of lower doses with the adjuvant (Lee et al., 1999).
• Description: A mucosal vaccine was used in an effort to elicit serum IgG and intestinal secretory IgA. A genetic hybrid of the Campylobacter jejuni flaA gene with LT-B of Escherichia coli and assessment of the efficacy of the hybrid protein has been developed an oral chicken vaccine (Wilkinson et al., 2003).

Mouse Response

• Host Strain: BALB/c
• Vaccination Protocol: Mice were immunized intranasally with two doses of 3 to 50 mg of MBP-FlaA, given 8 days apart, with or without 5 mg of the mutant E. coli heat-labile enterotoxin (LTR192G) as a mucosal adjuvant (Lee et al., 1999).
• Persistence: The results showed that, when challenged with bacteria, there was a reduction in colonization as early as 3 days after infection and that no campylobacter organisms could be detected in stools by 7 days post-feeding (Lee et al., 1999).
• Immune Response: Stimulation of FlaA-specific intestinal secretory IgA (sIgA) responses required immunization with higher doses of MBP-FlaA or co-administration of lower doses with the adjuvant (Lee et al., 1999).
• Side Effects: Animals were monitored for sickness and death for 5 days and only minimal adverse side effects were encountered (Lee et al., 1999).
• Challenge Protocol: Mice were intranasally challenged after the second vaccination. Fecal excretion of C. jejuni was monitored daily for 10-14 days after challenge by culturing fecal homogenates. Putative colonies were confirmed by morphology and oxidase reactions. Mice were challenged orally with 0.5 ml of various doses of C. jejuni. Fecal excretion was monitored as described above for 7-9 days (Lee et al., 1999).
• Efficacy: The full range of MBP-FlaA doses were effective in eliciting antigen-specific serum IgG responses, and these responses were enhanced by adjuvant use, except in the highest dosing group. When vaccinated mice were challenged intranasally 26 days after immunization, the best protection was seen in animals given 50 mg of MBP-FlaA plus LTR192G. The protective efficacies of this dose against disease symptoms and intestinal colonization were 81.1 and 84%, respectively. When mice which had been immunized intranasally were challenged orally with 8 x 10^10, 8 x 10^9, or 8 x 10^8 cells of strain 81-176, the protective efficacies against intestinal colonization at 7 days postinfection were 71.4, 71.4, and 100%, respectively (Lee et al., 1999).
• Description: It is interesting that antibodies generated during natural infection by either strain 81-176 or strain VC167 appear to react more strongly to glycosylated flagellins isolated from Campylobacter spp. than to unglycosylated, recombinant flagellins isolated from E. coli. Immunization with the recombinant fusion protein lacking post-translational modifications may lead to antibody production against epitopes which are less immunogenic in the native molecule due to differences in folding and/or masking by the carbohydrate moiety but are, nonetheless, capable of eliciting a protective immune response. Further evaluation of this recombinant flagellin is ongoing as a vaccine in a ferret diarrheal disease model (Lee et al., 1999).