A team of researchers identified a peptide that can fight infection by boosting the body's own immune system and may help in the fight against hospital superbugs.
"Antibiotics are now under threat because of the explosion in antibiotic-resistant bacteria," notes Robert Hancock, principal investigator and Canada Research Chair in Pathogenomics and Antimicrobials. "The beauty of this peptide is that it acts on the host to trigger a protective response and doesn't act on bacteria directly. That means it's unlikely bacteria will become resistant to it."
The team found that a peptide, dubbed innate defense regulator peptide (IDR-1), can increase innate immunity without triggering harmful inflammation and offer protection both before and after infection is present.
In animal models, the researchers tested the peptide's effectiveness against Staphylococcus aureus, including MRSA, vancomycin-resistant Enterococcus (VRE), and salmonella. In staph and VRE infections, although bacteria were not completely eradicated, IDR-1 significantly reduced bacteria counts and mortality, when given either 24–48 hours before or four hours after infection began. In salmonella, the peptide offered significant protection when administered prior to infection setting in.
Data showed that IDR-1 activates several signaling pathways to stimulate infection-clearing chemokines—a chemical mediator that mobilizes immune response.
In addition, the peptide did not produce harmful inflammation and toxicity often seen when the immune system is stimulated and, in fact, actually reduced the potentially harmful septic response.
The researchers anticipate the therapy may be useful as a supplement to antibiotics in combating common hospital infections such as ventilator-associated pneumonia, postsurgical infections, high-dose chemotherapy, and infections arising from insertion of catheters or other medical devices.
The study was carried out by a team at the University of British Columbia (UCB) in collaboration with university spin-off company, Inimex Pharmaceuticals. It was published in Nature Biotechnology.