• Vaccine Name: C. pneumoniae DNA vaccine encoding Ssb
• Target Pathogen: Chlamydophila pneumoniae
• Target Disease: Pneumonia
• Vaccine Ontology ID: VO_0011425
• Type: DNA vaccine
• Status: Research
• Antigen: C. pneumoniae single-stranded DNA-binding protein, ssb
• Ssb gene engineering:
  • Type: DNA vaccine construction
  • Description: The genome sequence of C. pneumoniae isolate CDC/CWL-029 (ATCC strain VR-1310) was extracted from Genbank (AE001363, 1,230,230 bp). The 1052 annotated genes of C. pneumoniae were imported into a gene-splitting and primer prediction program; primer pairs to amplify 1263 ORFs of 1.5 kb or less were exported. A 1.5 kb maximum ORF length was chosen to ensure sufficient PCR quality and yields, and this generated a few additional fragments (Li et al., 2006).
  • Detailed Gene Information: Click Here.
• DNA vaccine plasmid:
  • DNA vaccine plasmid name:
  • DNA vaccine plasmid VO ID: VO_0005027
• Immunization Route: Intramuscular injection (i.m.)

Mouse Response

• Host Strain: A/J
• Vaccination Protocol: For intranasal inoculation, mice received a light isoflurane inhalation anesthesia. Vaccine protection control mice were inoculated with a low dose of 5 × 10^6 C. pneumoniae elementary bodies in 30 μl SPG buffer (Li et al., 2006).
• Challenge Protocol: High-dose challenge infection was performed 4 weeks after the last gene gun genetic vaccination or low dose inoculation of live C. pneumoniae, and 6 weeks after the last intramuscular-intradermal genetic vaccination, by intranasal inoculation of 1 × 10^8 C. pneumoniae elementary bodies in 30 μl SPG buffer. Mice were sacrificed by CO2 inhalation 2 h, 3 days, 10 days, or 15 days after inoculation, and lungs and spleen were weighed, snap frozen in liquid nitrogen, and stored at −80 °C until further processing (Li et al., 2006).
• Efficacy: Mice vaccinated with candidate gene ssb showed significant reduction of spleen chlamydial loads as compared to naïve, non-protected control mice (p ≤ 0.048). This resulted in the ability of ssb to mediate a modest, but significant level of protection in an inbred A/J mouse respiratory challenge model (Li et al., 2006).