Angiotensin II–Induced Vascular Dysfunction Depends on Interferon-γ–Driven Immune Cell Recruitment and Mutual Activation of Monocytes and NK-Cells
Objective—Immune cells contribute to angiotensin II (ATII)–induced vascular dysfunction and inflammation. Interferon-γ (IFN-γ), an inflammatory cytokine exclusively produced by immune cells, seems to be involved in ATII-driven cardiovascular injury, but the actions and cellular source of IFN-γ remain incompletely understood.
Approach and Results—IFN-γ−/− and Tbx21−/− mice were partially protected from ATII-induced (1 mg/kg per day of ATII, infused subcutaneously by miniosmotic pumps) vascular endothelial and smooth muscle dysfunction, whereas mice overexpressing IFN-γ showed constitutive vascular dysfunction. Absence of T-box expressed in T cells, the IFN-γ transcription factor encoded by Tbx21, reduced vascular superoxide and peroxynitrite formation and attenuated expression of nicotinamid adenosin dinucleotid phosphate oxidase subunits as well as inducible NO synthase, monocyte chemoattractant protein 1, and interleukin 12 in aortas of ATII-infused mice. Compared with controls, IFN-γ−/− and Tbx21−/− mice were characterized by reduced ATII-mediated vascular recruitment of both NK1.1+ NK-cells as the major producers of IFN-γ and CD11b+Gr-1low interleukin-12 secreting monocytes. Selective depletion and adoptive transfer experiments identified NK-cells as essential contributors to vascular dysfunction and showed that T-box expressed in T cells+LysM+ myelomonocytic cells were required for NK-cell recruitment into vascular tissue and local IFN-γ production.
Conclusions—We provide first evidence that NK-cells play an essential role in ATII-induced vascular dysfunction. In addition, we disclose the T-box expressed in T cells–IFN-γ pathway and mutual monocyte–NK-cell activation as potential therapeutic targets in cardiovascular disease.
- Received February 22, 2013.
- Accepted March 5, 2013.
- © 2013 American Heart Association, Inc.