Myeloid Suppressor Cells Accumulate and Regulate Blood Pressure in Hypertension
Rationale: Chronic inflammation is a major contributor to the progressive pathology of hypertension and T cell activation is required for the genesis of hypertension. However, the precise role of myeloid cells in this process is unclear.
Objective: To characterize and understand the role of peripheral myeloid cells in the development of hypertension.
Methods and Results: We examined myeloid cells in the periphery of hypertensive mice and found that increased numbers of CD11b+Gr1+ myeloid cells in blood and the spleen is a characteristic of three murine models of experimental hypertension (Ang II, L-NAME, and high salt). These cells express surface markers and transcription factors associated with immaturity and immunosuppression. Also, they produce hydrogen peroxide to suppress T cell activation. These are characteristics of myeloid-derived suppressor cells (MDSCs). Depletion of hypertensive MDSCs increased blood pressure and renal inflammation. In contrast, adoptive transfer of wild-type MDSCs to hypertensive mice reduced blood pressure, while the transfer of NADPH oxidase 2-deficient MDSCs did not.
Conclusions: The accumulation of MDSCs is a characteristic of experimental models of hypertension. MDSCs limit inflammation and the increase of blood pressure through the production of hydrogen peroxide.
- Received March 25, 2015.
- Revision received August 19, 2015.
- Accepted August 20, 2015.