Urinary tract infections (UTIs) are a common and painful infection that can be surprisingly persistent. Now, researchers at Duke University have developed a vaccine that can be delivered via catheter to clear out the bacteria and prevent infections from recurring.
UTIs are caused by bacteria getting into the urinary tract, sometimes making it up into the bladder, where they can be hard to treat. Most of the time they require antibiotics taken either orally or intravenously, which can have the side effects of being system-wide carpet bombs. Worse still, these methods often don’t destroy the whole population of invaders in the bladder, paving the way for infections to return.
For the new study, the Duke researchers set out to investigate a more direct approach. In previous work, the team found that the reason bacteria stick around is because the immune system sends in more Th2 cells, which focus on repairing damaged tissue, rather than the Th1 cells that target bacterial pathogens.
So this time the researchers set out to boost that immune response. They developed a vaccine consisting of bacterial antigens combined with an adjuvant that summons more Th1 cells to the bladder.
The researchers tested this in mice with E. coli infections in their urinary tracts. One group received the vaccine through a catheter, delivered directly to the bladder, while the other received an injection. And sure enough, those that had the catheter method had more Th1 cells, eliminating the bacteria and preventing recurrence of infection.
“The new vaccine strategy attempts to ‘teach’ the bladder to more effectively fight off the attacking bacteria," says Jianxuan Wu, lead author of the study. “By administering the vaccine directly into the bladder where the residual bacteria harbor, the highly effective vaccine antigen, in combination with an adjuvant known to boost the recruitment of bacterial clearing cells, performed better than traditional intramuscular vaccination.”
While the results have only been shown in mice so far, the team says that it should be relatively simple to adapt to human clinical trials. That’s because the components of the vaccine have previously been shown to be safe for human use.
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: Duke University