Antibiotic protein with the ability to target pathogens expressing the blood group B antigen.
- Naturally occurring factors produced by humans.
- Induces rapid cell death in bacteria expressing the blood group B antigen.
- Does not harm commensal bacteria.
Emory University scientists have successfully demonstrated in vivo that two Galectin family members, Galectin-4 and -8, possess antibiotic properties that effectively treat pathogenic E. coli infections. Galectin interaction with cell surface antigens resembling blood group B provides a means to selectively target and eliminate these bacteria. They have demonstrated that oral administration of either purified protein in mice selectively kills E. coli expressing the blood group B antigen while leaving commensal flora of the gut unperturbed. The antibiotic properties of Galectin-4 and -8 are quite potent, with IC50 values in the nanomolar range. At these doses E. coli expressing the blood group B antigen are quickly and selectively immobilized, and their membranes destabilized. As a number of pathogens express the blood group B antigen, it is expected that Galectin-4 and -8 will serve as effective treatments against a wide range of pathogenic diseases.
Largely due to antibiotic misuse, the incidence of antibiotic resistant infections is on the rise. This is especially troubling, as pathogenic strains have been identified that are resistant to even the newest antibiotic compounds. Galectins offer a solution to combat this resistance; any change in the Galectin recognition site will expose the pathogen to host immune cells that it is trying to avoid. Thus, the novel nature of Galectin interactions not only poses an attractive mechanism for targeting pathogens without disrupting commensal bacteria, but also will extend the life cycle and effectiveness of the drug.
- In vivo proof of principle has been demonstrated in rodent models.
- Bacterial resistance to the most recent chemical antibiotics has already been identified.