Role of T lymphocytes in hypertension

Abstract

Accumulating evidence indicates that the immune system plays a critical role in the pathogenesis of cardiovascular diseases including hypertension. Mice lacking T lymphocytes are resistant to blood pressure elevation, suggesting a key contribution of T lymphocytes to hypertension. However, the individual T cell subsets, including CD8(+), Th1, Th17, and T regulatory T cells have shown widely discrepant effects on blood pressure and target organ damage in this disorder. Moreover, the activation state of a T lymphocyte population exerts considerable influence over its role in hypertension. In turn, activated T cells regulate blood pressure through the elaboration of reactive oxygen species and vasoactive cytokines, altering the inflammatory milieu in the vascular wall and the kidney. Recent GWAS studies similarly point to a role for T lymphocytes in human hypertension.

Figure 1. The role of T lymphocytes in hypertension

A neo-antigen presented on the surface of an antigen presenting cell (APC) in the context of a major histocompatibility complex (MHC) to the T cell receptor (TCR) on the surface of the T lymphocyte triggers (a) secretion of inflammatory cytokines, (b) generation of reactive oxygen species (ROS), and (c) activation of surrounding myeloid and lymphocyte populations that generate additional ROS and make their own contribution to the cytokine milieu. These cytokines and ROS, in turn, modulate blood pressure through effects on vascular function and renal sodium handling.