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

Journal Article (Journal Article)

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.

Full Text

Duke Authors

Cited Authors

  • Leisman, DE; Privratsky, JR; Lehman, JR; Abraham, MN; Yaipan, OY; Brewer, MR; Nedeljkovic-Kurepa, A; Capone, CC; Fernandes, TD; Griffiths, R; Stein, WJ; Goldberg, MB; Crowley, SD; Bellomo, R; Deutschman, CS; Taylor, MD

Published Date

  • August 23, 2022

Published In

Volume / Issue

  • 119 / 34

Start / End Page

  • e2211370119 -

PubMed ID

  • 35969740

Pubmed Central ID

  • PMC9407661

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

Digital Object Identifier (DOI)

  • 10.1073/pnas.2211370119

Language

  • eng

Conference Location

  • United States