• Vaccine Ontology ID: VO_0011426
• Type: DNA vaccine
• Status: Research
• Antigen: C. psittaci ompA
• ompA gene engineering:
  • Type: DNA vaccine construction
  • Description: To enhance the expression of MOMP in turkey cells, the coding sequence of the ompA gene was adapted and optimised to the codon usage in birds (GenScript Corporation, New Jersey, USA) in order to increase the codon adaptation index (CAI). The CAI was calculated (http://www.evolvingcode.net/codon/cai/cai.php) based on the most frequent codon usage in chickens and turkeys. EGFP was cloned downstream from the codon optimised ompAopt into the EcoRV restriction site of pcDNA1, resulting in the final construct: pcDNA1/MOMPopt–EGFP. Plasmid DNA was propagated in Escherichia coli MC1061/P3, purified using the EndoFree® Plasmid Giga kit (Qiagen, Venlo, The Netherlands) and dissolved in 20 mM Hepes buffer (pH 7.4). Following purification, a PCR reaction on the plasmid was performed with vector associated SP6 and T7 primers to amplify the fusion construct cloned into the multicloning site of pcDNA1(Verminnen et al., 2010).
  • Detailed Gene Information: Click Here.
• Vector: pcDNA1
• Immunization Route: Intramuscular injection (i.m.)

Turkey Response

• Host Strain: SPF
• Vaccination Protocol: Three groups received a primary DNA inoculation at 1 day of age and one booster inoculation 3 weeks later. Groups 1 and 2 were twice immunised intramuscularly with respectively naked plasmid DNA or brPEI-pcDNA/MOMPopt, while group 3 was vaccinated at both time points through nebulisation of brPEI-pcDNA/MOMPopt. The control group (4) was left unvaccinated (Verminnen et al., 2010).
• Challenge Protocol: Turkeys were challenged by aerosol infection at the age of 5.5 weeks using the Cirrus™ nebulizer. The challenge infection consisted of 108 TCID50 of Cp. psittaci strain 92/1293 (avian genotype D strain). All turkeys were euthanized at 25 days post-challenge (PC) (Verminnen et al., 2010).
• Efficacy: The ompA codon was adapted to the codon usage in birds, resulting in pcDNA1/MOMP(opt). Researchers examined the capacity of nebulised or intramuscularly (IM) administered brPEI-pcDNA1/MOMP(opt) to induce a significant protective immune response in SPF turkeys experimentally infected with 10^8 TCID(50) of a virulent Cp. psittaci strain. Vaccinated groups were significantly protected against Cp. psittaci challenge (Verminnen et al., 2010).