Tailored for the job

Pseudomonas aeruginosa bacteria currently pose a serious threat to human health worldwide. Not only can these germs cause severe infections, especially in vulnerable individuals, but they are also increasingly resistant to a wide range of antibiotics. New therapeutic approaches are urgently needed.

Based on animal data, some researchers consider monoclonal antibodies to be a promising alternative to antibiotics for treating Pseudomonas infections. Produced by immune ‘B cells’, these tiny molecules are designed to recognize and neutralize germs with incredible specificity and precision. This process starts with an initial exposure to the pathogen, which allows the body to ‘learn’ how to produce the antibodies against this target. As a result, a dedicated population of B cells carries the genetic sequences necessary to ultimately produce pathogen-specific antibodies.

Initial attempts to treat human Pseudomonas infections using monoclonal antibodies have proven safe but largely ineffective. One possible reason is that these trials used mouse-derived antibodies, which may not work as well in people. Typically, successful monoclonal therapies, such as the ones developed for COVID-19, rely on human sequences from individuals who have recovered from infection. In response, Hale et al. set out to design new monoclonal antibodies using a similar approach.

To isolate human Pseudomonas-specific immune memory B cells, they turned to blood samples from patients with cystic fibrosis, who frequently experience infections caused by these bacteria. Having collected the genetic sequences that help generate monoclonal antibodies against Pseudomonas in these individuals, Hale et al. were able to create human antibodies that could strongly bind to Pseudomonas aeruginosa cells and effectively treat infected mice. While further investigation is needed, these findings may help develop new and more effective therapies against these deadly bacteria.