In the field of research exploring the connection existing between hypertension and immune system, CD8 effector T cells emerge as the possible mediators of target organ colonization. In the absence of overt inflammation or pathogen response, naïve T cells circulate from the blood into secondary lymphoid organs, where, upon challenge, become activated. Then, they differentiate into effector T cells, which display typical activation patterns. However, less is known about the intracellular signaling pathways that are responsible for the acquisition of effectors functions in T cells. The p110γ isoform of the PI3K family has unique features, being crucially involved in the immune and cardiovascular systems. On this issue, we have described that PI3Kγ has a crucial role in blood pressure regulation, being KO mice protected from AngII-induced hypertension. Moreover, we found that mice with a constitutively active PI3Kγ isoform (CAAX mice) were spontaneously hypertensive (SBP: CAAX 135 ± 3 vs WT 105 ± 4 mmHg, p<0.001). Interestingly, PI3Kγ is known to play a selective role in regulating the migration of effector CD8 T cells, even though there was no effect of PI3Kγ in naïve T cells. Thus we explored the possible involvement of PI3Kγ in the crosstalk between hypertension and immunity. CAAX mice displayed a significant infiltration of activated CD8
+
CD69
+
T cells in kidney, as compared to WT mice (10.2 ± 2.1 vs 2.8 ± 0.6 *10
4
cells/kidney, p<0.01). At the functional level, this phenotype was associated with enlarged Bowman’s spaces and fibrosis in the kidney of CAAX mice, leading to disruption of renal function, as shown by later development of proteinuria. In the end, to demonstrate whether the CAAX hypertensive phenotype, associated to renal damage after CD8 colonization, could be ascribed to the overactivation of PI3Kγ signaling in this immune cell type, we performed an adoptive transfer of CD8 T cells isolated from CAAX mice in WT mice. Strikingly we found that CD8 T cells with constitutively active PI3Kγ were effective to induce hypertension in naïve mice. These data suggest that in the development of hypertension, PI3Kγ signaling in CD8 T cells is crucial for their accumulation in the kidney, likely contributing to increase in blood pressure by altering renal function.