Researchers at the University of Colorado Boulder have found that bacteria and human cells fight off invaders similarly: they have the same basic machinery to turn on and off immune pathways.
The study, published in Nature, sheds light on the shared ancient machinery, a cluster of enzymes known as ubiquitin transferases. A better understanding of this machine could lead to novel approaches for treating various human diseases, from autoimmune disorders to neurodegenerative diseases.
The study is not the first to highlight the lessons that bacteria can teach humans. There is growing evidence that parts of the human immune system may have originated from bacteria, with evolution yielding more complex versions of bacteria’s virus-fighting tools.
The study focuses on a protein called cGAS, which is present in humans and bacteria and is critical for mounting a defense when the cell senses a viral invader. Using cryo-electron microscopy, the researchers discovered additional proteins that bacteria use to help cGAS defend the cell from viral attack and that bacteria modify cGAS using a streamlined version of ubiquitin transferases.
The study reveals how the machine works, identifying two key components, Cap2 and Cap3, which serve as on and off switches for the cGAS response. The authors believe that pieces of the bacterial ubiquitin transferase machine could be programmed to edit out problem proteins and treat human diseases. The more the scientific community understands ubiquitin transferases, the better equipped it will be to target these proteins therapeutically.
References
Ledvina, H. E., Ye, Q., Gu, Y., Sullivan, A. E., Quan, Y., Lau, R. K., Zhou, H., Corbett, K. D., & Whiteley, A. T. (2023). An E1–E2 fusion protein primes antiviral immune signalling in bacteria. Nature, 1–7. https://doi.org/10.1038/s41586-022-05647-4
Marshall, L. (2023, February 8). We’re not so different: Bacterial weapons could help fight human diseases. CU Boulder Today; University of Colorado Boulder. https://www.colorado.edu/today/2023/02/08/were-not-so-different-bacterial-weapons-could-help-fight-human-diseases
