Differential phenotypes of tissue-infiltrating T cells during angiotensin II-induced hypertension in mice

PLoS One. 2014 Dec 11;9(12):e114895. doi: 10.1371/journal.pone.0114895. eCollection 2014.

Abstract

Hypertension remains the leading risk factor for cardiovascular disease (CVD). Experimental hypertension is associated with increased T cell infiltration into blood pressure-controlling organs, such as the aorta and kidney; importantly in absence of T cells of the adaptive immune system, experimental hypertension is significantly blunted. However, the function and phenotype of these T cell infiltrates remains speculative and undefined in the setting of hypertension. The current study compared T cell-derived cytokine and reactive oxygen species (ROS) production from normotensive and hypertensive mice. Splenic, blood, aortic, kidney and brain T cells were isolated from C57BL/6J mice following 14-day vehicle or angiotensin (Ang) II (0.7 mg/kg/day, s.c.) infusion. T cell infiltration was increased in aorta, kidney and brain from hypertensive mice. Cytokine analysis in stimulated T cells indicated an overall Th1 pro-inflammatory phenotype, but a similar proportion (flow cytometry) and quantity (cytometric bead array) of IFN-γ, TNF-α, IL-4 and IL-17 between vehicle- and Ang II- treated groups. Strikingly, elevated T cell-derived production of a chemokine, chemokine C-C motif ligand 2 (CCL2), was observed in aorta (∼6-fold) and kidney in response to Ang II, but not in brain, spleen or blood. Moreover, T cell-derived ROS production in aorta was elevated ∼3 -fold in Ang II-treated mice (n = 7; P<0.05). Ang II-induced hypertension does not affect the overall T cell cytokine profile, but enhanced T cell-derived ROS production and/or leukocyte recruitment due to elevated CCL2, and this effect may be further amplified with increased infiltration of T cells. We have identified a potential hypertension-specific T cell phenotype that may represent a functional contribution of T cells to the development of hypertension, and likely several other associated vascular disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II / administration & dosage*
  • Animals
  • Aorta / metabolism
  • Aorta / pathology
  • Blood Pressure
  • Humans
  • Hypertension / chemically induced
  • Hypertension / metabolism*
  • Hypertension / pathology
  • Interleukin-17 / metabolism
  • Interleukin-4 / metabolism
  • Mice
  • Phenotype
  • Reactive Oxygen Species / metabolism
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism
  • Vascular Diseases / metabolism*
  • Vascular Diseases / pathology

Substances

  • IL17A protein, human
  • Interleukin-17
  • Reactive Oxygen Species
  • TNF protein, human
  • Tumor Necrosis Factor-alpha
  • Angiotensin II
  • Interleukin-4

Grants and funding

This work was supported by a Monash Larkins Fellowship (AV) and Ramaciotti Foundation Establishment Grant (3227/2011). AV was supported by a Heart Foundation of Australia Postdoctoral Fellowship (PF12M6922), while ZW received an Australian Postgraduate Award. None of the funding sources outlined above had any role in study design; collection, analysis and interpretation of data; writing of the report; or in the decision to submit the article for publication.