• Vaccine Name: E. coli IreA protein vaccine
• Target Pathogen: Escherichia coli
• Target Disease: Hemorrhagic colitis
• Vaccine Ontology ID: VO_0011444
• Type: Subunit vaccine
• Status: Research
• Antigen: E. coli iron-regulated outer membrane virulence protein (IreA)
• ireA gene engineering:
  • Type: Recombinant protein preparation
  • Description: Genes encoding the selected antigens were PCR-amplified from CFT073 genomic DNA and cloned into either pBAD-myc-HisA (Invitrogen) or pET30b+ (Novagen). The six iron receptor vaccine candidates, ChuA, Hma, IutA, IreA, Iha, and IroN were expressed and purified as affinity-tagged recombinant proteins. Consistent with the predicted structure of these antigens, the CD spectrum of refolded purified Hma displayed a trough at 218 nm, which is characteristic of a β-sheet-rich conformation. The six purified protein antigens were each biochemically cross-linked to the adjuvant cholera toxin (CT) at a ratio of 101 (Alteri et al., 2009).
  • Detailed Gene Information: Click Here.
• Adjuvant:
  • Adjuvant name:
  • VO adjuvant ID: VO_0000143
• Immunization Route: Intranasal

Mouse Response

• Host Strain: CBA/J
• Vaccination Protocol: Purified antigens were chemically cross-linked to cholera toxin (CT) (Sigma) at a ratio of 101 using N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) (Pierce) according to the manufacturer's recommendations. Peptide antigens were dissolved in 1 mM EDTA in PBS, mixed with reduced CT, and incubated at 4°C for 18 h. All immunizations were administered intranasally in a total volume of 20 µl/animal (10 µl/nare). Animals received a primary dose on day 0 of 100 µg crosslinked antigen (containing 10 µg CT) or 10 µg CT alone. Two boosts of 25 µg antigen (crosslinked to 2.5 µg CT) or 2.5 µg CT alone were given on days 7 and 14 (Alteri et al., 2009).
• Challenge Protocol: The animals were transurethrally challenged with UPEC strain CFT073 and protection was assessed at 48 h post infection (hpi) by determining CFUs in the urine, bladder, and kidneys (Alteri et al., 2009).
• Efficacy: Immunization with IreA protects against urinary tract colinization by E.coli CFT073 and reduces colinization by E.coli 536 in the bladder of CBA/J mice (Alteri et al., 2009).
• Host Ifng (Interferon gamma) response
  • Description: Mouse splenocytes were measured for IFN-gamma and IL-17 production after vaccination but before challenge, and after challenge. Mice vaccinated with IreA produced significantly higher IFN-gamma levels than mice immunized with the adjuvant alone (CT vaccinated) both before and after challenge (Alteri et al., 2009).
  • Detailed Gene Information: Click Here.
• Host IL-17 response
  • Description: Mouse splenocytes were measured for IFN-gamma and IL-17 production after vaccination but before challenge, and after challenge. Mice vaccinated with IreA produced significantly higher IL-17 levels than mice immunized with the adjuvant alone (CT vaccinated) both before and after challenge (Alteri et al., 2009).
  • Detailed Gene Information: Click Here.