Scientists in Israel have discovered a new part of the human immune system, shedding light on a potential “untapped source of natural antibiotics.” The research focuses on protaesomes, structures inside cells that, according to the Israel Cancer Research Fund, essentially function as “cellular garbage cans,” helping remove “unwanted or damaged proteins and helping the immune system recognize harmful invaders and cancer cells.”
Now, as detailed in the scientific journal Nature and illuminated by the BBC, the new study has “addressed a question that remained unanswered for decades,” showing that proteasomes can detect bacteria in cells—and then use old proteins as defense against that bacteria.”
“These findings pave the way for previously undescribed diagnostic and therapeutic strategies in the fight against infectious diseases,” the researchers wrote in the paper.
Yifat Merbl, a researcher and professor from the Weizmann Institute of Science in Rehovot, Israel, called the results “really exciting,” telling the BBC, “[W]e never knew that this was happening. […] We discovered a novel mechanism of immunity that is allowing us to have a [defense] against bacterial infection. […] It’s happening throughout our body in all the cells, and generates a whole new class of potential natural antibiotics.”
The discovery process, likened to “dumpster diving,” led to tests involving lab-grown bacteria and mice with pneumonia and sepsis.
“Experiments in these mice showed that treatment with a proteasome-derived peptide significantly reduced the number of bacteria, lessened tissue damage, and even improved survival rates,” according to the Weizmann Institute’s news release. “The results surprised the researchers for two reasons. First, they showed that a single peptide that is naturally made by the body can prove effective against a life-threatening condition when administered in large amounts. Second, the results of the treatment were comparable to those of treatment with strong antibiotics in clinical use.”
Professor Daniel Davis, an immunologist at Imperial College London, told the BBC that the discoveries are “extremely provocative and very interesting,” while noting that the possibility of another source of antibiotics “still needs to be tested” and would require patience.
“This study highlights how technological innovation and basic research intertwine in unforeseen ways,” Merbl said in the news release. “Without the technology that allowed us to analyze the cellular trash, we would not have made this discovery, but when we developed this technology, we never imagined that we would uncover a new immune mechanism.”
Hopefully these findings will spur further research in the fight against superbugs resistant to currently available drugs. Antimicrobial resistance is a major ongoing concern—according to the World Health Organization, bacterial AMR “was directly responsible for 1.27 million global deaths in 2019 and contributed to 4.95 million deaths.”
Professor Merbl, who studied at the Weizmann Institute of Science and Harvard University, joined Weizmann as a Senior Scientist in 2014 and served as the scientific co-founder of Promise Bio, a company utilizing “a cloud-based AI platform that performs unbiased, broad-range epiproteomic analyses on standard mass-spectrometry data.”
In May 2024, the Israel Cancer Research Fund partnered with the Cancer Research Institute to fund Merbl’s work. Her lab team previously received a $200,000 CRI-ICRF Technology Impact Award, along with the 2024 Rappaport Prize for Excellence in Biomedical Research.
