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Angiotensin II enhances bacterial clearance via myeloid signaling in a murine sepsis model

Sepsis, defined as organ dysfunction caused by a dysregulated host-response to infection, is characterized by immunosuppression. The vasopressor norepinephrine is widely used to treat low blood pressure in sepsis but exacerbates immunosuppression. An alternative vasopressor is angiotensin-II, a pept...

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Detalles Bibliográficos
Autores principales: Leisman, Daniel E., Privratsky, Jamie R., Lehman, Jake R., Abraham, Mabel N., Yaipan, Omar Y., Brewer, Mariana R., Nedeljkovic-Kurepa, Ana, Capone, Christine C., Fernandes, Tiago D., Griffiths, Robert, Stein, William J., Goldberg, Marcia B., Crowley, Steven D., Bellomo, Rinaldo, Deutschman, Clifford S., Taylor, Matthew D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: National Academy of Sciences 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9407661/
https://www.ncbi.nlm.nih.gov/pubmed/35969740
http://dx.doi.org/10.1073/pnas.2211370119
Descripción
Sumario:Sepsis, defined as organ dysfunction caused by a dysregulated host-response to infection, is characterized by immunosuppression. The vasopressor norepinephrine is widely used to treat low blood pressure in sepsis but exacerbates immunosuppression. An alternative vasopressor is angiotensin-II, a peptide hormone of the renin-angiotensin system (RAS), which displays complex immunomodulatory properties that remain unexplored in severe infection. In a murine cecal ligation and puncture (CLP) model of sepsis, we found alterations in the surface levels of RAS proteins on innate leukocytes in peritoneum and spleen. Angiotensin-II treatment induced biphasic, angiotensin-II type 1 receptor (AT1R)-dependent modulation of the systemic inflammatory response and decreased bacterial counts in both the blood and peritoneal compartments, which did not occur with norepinephrine treatment. The effect of angiotensin-II was preserved when treatment was delivered remote from the primary site of infection. At an independent laboratory, angiotensin-II treatment was compared in LysM-Cre AT1aR(−/−) (Myeloid-AT1a(−)) mice, which selectively do not express AT1R on myeloid-derived leukocytes, and littermate controls (Myeloid-AT1a(+)). Angiotensin-II treatment significantly reduced post-CLP bacteremia in Myeloid-AT1a(+) mice but not in Myeloid-AT1a(−) mice, indicating that the AT1R-dependent effect of angiotensin-II on bacterial clearance was mediated through myeloid-lineage cells. Ex vivo, angiotensin-II increased post-CLP monocyte phagocytosis and ROS production after lipopolysaccharide stimulation. These data identify a mechanism by which angiotensin-II enhances the myeloid innate immune response during severe systemic infection and highlight a potential role for angiotensin-II to augment immune responses in sepsis.