Daniel Leisman, MD, a resident in the Department of Medicine at Massachusetts General Hospital, is the lead author of a new study in the Proceedings of the National Academy of Sciences (PNAS) titled Angiotensin II Enhances Bacterial Clearance via Myeloid Signaling in a Murine Sepsis Model .
What was the question you set out to answer with this study?
Does angiotensin-II enhance immune function and defense against severe bacterial infections?
Sepsis, a dysregulated immune response to infection, often causes life-threateningly low blood pressure that requires treatment with norepinephrine.
However, norepinephrine is immunosuppressive and may impair bacterial defense. Angiotensin-II, a cardiovascular hormone, is an alternative, recently approved treatment for low blood pressure but whether angiotensin-II impacts immune function in sepsis is unknown.
What are two or three key takeaways?
What were your conclusions?
In this study, angiotensin-II acted directly on immune cells to enhance bacterial killing functions, increase bacterial clearance, and modulate systemic inflammatory responses without increasing inflammatory injury.
These immune supporting effects suggest angiotensin-II may have a role in sepsis treatment not just to increase blood pressure, but also as an immunomodulator targeting the immune dysregulation that leads to sepsis.
Paper cited:
Leisman, D. E., Privratsky, J. R., Lehman, J. R., Abraham, M. N., Yaipan, O. Y., Brewer, M. R., Nedeljkovic-Kurepa, A., Capone, C. C., Fernandes, T. D., Griffiths, R., Stein, W. J., Goldberg, M. B., Crowley, S. D., Bellomo, R., Deutschman, C. S., & Taylor, M. D. (2022). Angiotensin II enhances bacterial clearance via myeloid signaling in a murine sepsis model . Proceedings of the National Academy of Sciences of the United States of America , 119 (34), e2211370119. https://doi.org/10.1073/pnas.2211370119
About Massachusetts General Hospital
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The Mass General Research Institute conducts the largest hospital-based research program in the nation, with annual research operations of more than $1 billion and comprises more than 9,500 researchers working across more than 30 institutes, centers and departments. In July 2022, Mass General was named #8 in the U.S. News & World Report list of "America’s Best Hospitals." MGH is a founding member of the Mass General Brigham healthcare system.
Proceedings of the National Academy of Sciences
Experimental study
Animals
Angiotensin II enhances bacterial clearance via myeloid signaling in a murine sepsis model
19-Aug-2022