• Vaccine Name: E. coli Hma protein vaccine
• Target Pathogen: Escherichia coli
• Target Disease: Hemorrhagic colitis
• Vaccine Ontology ID: VO_0011443
• Type: Subunit vaccine
• Status: Research
• Antigen: E. coli outer membrane receptor for iron compound or colicin (Hma)
• Hma 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 10:1 (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: A vaccine made by Hma from E. coli strain CFT073 and 536 induced protection to the infection of virulent strain CFT073 and 536, respectively, in the bladder in the CBA/J mice. (Alteri et al., 2009).