Researchers at Texas A&M University are examining how the body's immune system deploys copper to combat urinary tract infections, hoping the work will open routes to treating bacteria that no longer respond to standard antibiotics. The project is based at the university's College of Veterinary Medicine and Biomedical Sciences and is backed by a $1.48 million grant from the National Institutes of Health, according to Tribune Online.
The study extends earlier work by Dr Sarguru Subash, an associate professor in the college's Department of Veterinary Pathobiology, whose laboratory found that copper concentrations in the urinary tract climb during an infection and assist the body in fighting off bacteria.
Why it matters
Antibiotic resistance is eroding the effectiveness of medicines relied on to clear common infections, and UTIs are among the conditions where resistant bacteria pose a growing problem. A treatment strategy that strengthens the immune system's own defences rather than only attacking bacteria directly could offer an alternative path. The Texas A&M work is still at the research stage, but it targets a mechanism the body already uses naturally.
How copper works against bacteria
Copper is needed for normal health in people and animals, but in large amounts it harms bacteria. The immune system takes advantage of this, Tribune Online reports. Certain immune cells take in bacteria and subject them to antimicrobial substances, copper among them.
The difficulty is that some bacteria have developed ways to survive this attack. They can expel surplus copper or reduce its harmful effects, which lets them persist despite the immune response. Subash's team plans to study the genetic systems behind that tolerance, looking for weak points that new medicines could exploit.
Subash said the importance of copper is established, but that it leaves many unanswered questions about how these pathogens adjust to higher copper levels, according to Tribune Online.
If scientists can learn how bacteria get around copper-based defences, they may be able to design treatments that leave the pathogens more exposed to the immune system.
Targeting the bacteria's grip on the bladder
The team is also following evidence that copper may interfere with fimbriae, the fine hair-like appendages bacteria use to fasten themselves to cells lining the bladder. That attachment is what allows an infection to take hold. Bacteria that cannot anchor firmly are more likely to be carried away by the normal flow of urine.
Breaking down these structures could therefore help bring infections under control, especially if used together with treatments that kill bacteria outright.
Subash said bacterial defences may weaken when they face copper alongside other immune responses. According to Tribune Online, he noted that whether the body contains an infection or the condition develops into clinical disease depends in part on which side has the upper hand.
The researchers are additionally studying ceruloplasmin, a protein that contains copper and may help move it to where it is needed during a UTI. Because too much copper can injure healthy cells, the body regulates its transport and storage closely. The team will look at how ceruloplasmin helps release copper during infection and how that contributes to limiting bacterial growth.
Compounds that work with the immune system
Subash's laboratory has already identified an experimental antimicrobial compound that performs better when copper is present. The researchers intend to alter and test similar compounds in the search for candidates that could complement the immune response.
This approach pairs the direct bacteria-killing effect of a potential drug with the body's own defences, which the team sees as a possible way around antibiotic resistance.
Subash said the goal is to understand the fundamentals of how the immune system controls pathogens so that next-generation antimicrobials can be developed that do not rely solely on killing bacteria directly but also act in concert with the immune system, Tribune Online reports.
The research may have uses beyond human medicine. It could be relevant to veterinary practice, particularly for dogs that suffer repeated UTIs. Since some of the bacteria behind UTIs can also infect other parts of the body, the findings may also inform later work on other bacterial diseases.
What to watch: whether the team's genetic studies and compound testing produce a candidate that can be developed further with immune-system support in mind.
