• Vaccine Name: C. abortus DNA vaccine encoding MOMP
• Target Pathogen: Chlamydophila abortus
• Target Disease: Abortion and fetal death
• Vaccine Ontology ID: VO_0011430
• Type: DNA vaccine
• Status: Research
• Antigen: C. abortus major outer membrane protein omp1
• omp1 gene engineering:
  • Type: DNA vaccine construction
  • Description: The momp (omp1) gene was amplified by PCR and cloned into the vector pcDNA3.1 (Invitrogen) carrying the human cytomegalovirus immediate early promoter and the bovine growth hormone polyadenylation signal. The PCR was performed using chlamydial genomic DNA (80 ng) as template with dNTPs (200 µM each), specific primers (1 µM each) and 1 U Pfu DNA polymerase (Promega) in a Perkin Elmer 9600 thermocycler. The resulting fragment was inserted into the vector pcDNA3.1 after linearization by EcoRI/XhoI double digestion to generate pcDNA3.1 : : MOMP. The plasmid pcDNA3.1 : : MOMP and the pcDNA3.1 control plasmid were purified after an overnight Luria–Bertani culture of recombinant Escherichia coli DH5 using the EndoFree Plasmid Mega kit (Qiagen). Plasmid DNA was dissolved at 1 µg µl-1 in endotoxin-free PBS (Sigma) (Héchard et al., 2003).
  • Detailed Gene Information: Click Here.
• DNA vaccine plasmid:
  • DNA vaccine plasmid name:
  • DNA vaccine plasmid VO ID: VO_0000158
• Immunization Route: Intramuscular injection (i.m.)

Mouse Response

• Host Strain: OF1 Swiss
• Vaccination Protocol: Prior to DNA immunization, each mouse was injected with cardiotoxin (Latoxan) into the tibialis anterior muscles of both hind legs to enhance the uptake of plasmid DNA (Davis et al., 1993). Five days later, mice were anaesthetized by an intraperitoneal injection of ketamine and xylazine (respectively 80 and 8 mg kg-1 body weight) and immunized with pcDNA3.1 : : MOMP plasmid by intramuscular injections (50 µg in each tibialis anterior). Mice were boosted in the same way at days 21 and 42. The negative-control mice were immunized intramuscularly with endotoxin-free PBS (virulence control) or pcDNA3.1 plasmid. Positive-control mice were immunized with one subcutaneous injection of 4 x 10^4 p.f.u. of the live attenuated 1B vaccine at day 1 (Héchard et al., 2003).
• Challenge Protocol: The five groups of pregnant mice were mated at day 44. Non-pregnant and pregnant mice were challenged at day 58 by an intraperitoneal injection of 4 x 10^4 p.f.u. C. abortus AB7. One group of pregnant mice neither immunized nor challenged was kept as a control for the pregnancy (gestation control) (Héchard et al., 2003).
• Efficacy: The MOMP (omp1) DNA immunization induced a non-specific and partial protection in OF1 outbred mice fetuses against challenge with C. abortus (Héchard et al., 2003).
• Host Ighv1-9 response
  • Description: In non-pregnant mice, the MOMP DNA vaccine elicited a specific humoral response with predominantly serum IgG2a antibodies, suggesting a Th1-type immune response. No antibody response was detected in non-immunized mice or mice immunized with the control plasmid. The anti-MOMP IgG titre reached a maximum in the non-pregnant mice immunized with pcDNA3.1 : : MOMP after the third DNA injection (day 56) and decreased after challenge (day 63) (Héchard et al., 2003).
  • Detailed Gene Information: Click Here.