Neuromed, a new immune mechanism that contributes to hypertension identified

A new piece is added to the line of research carried out by the Angiocardioneurology and Translational Medicine Unit of the IRCCS Neuromed in Pozzilli regarding the link between the immune system and arterial hypertension. A study published in Nature Communications has in fact identified a mechanism through which CD8 T lymphocytes can contribute to this pathology: an intracellular enzyme, PI3Kγ, guides their activation and migration to key organs such as the kidneys and the vascular district, where they trigger an inflammatory response capable of altering blood pressure regulation. Using animal models, scientists were able to observe that constant activation of the PI3Kγ enzyme leads to the development of hypertension even without exposure to traditional risk factors. Once activated, CD8 T cells migrate from the spleen to peripheral tissues, establishing direct contact with the walls of the arteries. This “dialogue” between the immune system and the cardiovascular system results in increased vessel stiffness and an alteration of blood pressure control. “Our research – says Daniela Carnevale, Full Professor at Sapienza University of Rome, at the IRCCS Neuromed – has shown that the activation of PI3Kγ in these cells is sufficient to trigger a chain of events: the cells are activated even without external stimuli, move into peripheral tissues and contribute to modifying the reactivity of the vessels, increasing the risk of organ damage”. The researchers demonstrated that PI3Kγ enables CD8 lymphocytes to produce an inflammatory molecule, RANTES/CCL5, which facilitates tissue infiltration and the formation of an interface with vascular cells. By blocking this molecule, the hypertensive effect disappears. An important piece of information from the point of view of possible future applications of this research is the fact that the same type of activation was observed in CD8 lymphocytes present in the kidneys of hypertensive patients, indicating that this mechanism could also be relevant in humans.

“These results – comments Giuseppe Lembo, Full Professor at Sapienza University of Rome, at the IRCCS Neuromed – shed new light on the role of immunity in regulating blood pressure, indicating a possible way to protect the target tissues of hypertension, in particular the kidneys, by pharmacologically intervening on the PI3Kγ signal or on the RANTES molecule produced by lymphocytes”.