Autonomic regulation of the immune system and its implications for hypertension

This presentation was given by Matthew Bailey from the British Heart Foundation Centre for Cardiovascular Science of the University of Edinburgh, Scotland. It was presented at the ISN’s Forefronts Symposium 2015 taking place in Shenzhen, China, on October 22-25, 2015 for which the theme was ‘Immunomodulation of Cardio-Renal Function’ during Session 6: Hypertension, Metabolism and Immunity.

View the Presentation:

Presentation Abstract:  

Cardiovascular disease and chronic kidney disease exert a large socioeconomic burden on global health. Hypertension remains the major modifiable risk factor for both conditions yet in a large number of affected individuals, blood pressure control is poor. Poor control rates partly reflect a persistent knowledge gap: in the majority of cases the underlying causes of hypertension are unclear and the pathophysiology complex. 

Extensive research shows that inappropriate activation of the renin-angiotensin-aldosterone system (RAAS) contributes to high blood pressure by promoting vasoconstriction and sodium retention; a role for over-activity of the sympathetic nervous system is similarly well-documented. Hypertension may also have an inflammatory component involving both the innate and adaptive immune systems. Each of these systems offers distinct therapeutic strategies for blood pressure control. Potentially more important, however, is the concept that these systems interact. For example, chronic activation of the RAAS enhances sympathetic tone, which in turn directly enhances the immune response. Any single component of the neuro-immune-endocrine axis may initiate hypertension. When acting in concert, the progression of cardiovascular or renal disease is accelerated. 

This talk will review the major studies in this area to establish points of convergence between the autonomic nervous system, the immune system and the RAAS. Recent data from our laboratory will be presented, illustrating a novel contribution of macrophages to blood pressure homeostasis. Unraveling the complex biology of the neuro-immune-endocrine axis is challenging but it is likely to improve our understanding of hypertension and offer mechanism-based therapies to restore blood pressure control.