CD1d‐Dependent Natural Killer T Cells Mediate Hypertension and Vascular Injury Through Interleukin‐17A

BACKGROUND: Different T‐lymphocyte subsets, including CD1d‐dependent natural killer T (NKT) cells, play distinct roles in hypertension, highlighting the importance of identifying key immune cells for its treatment. This study aimed to determine the unknown effects of CD1d‐dependent NKT cells on hypertension and vascular injury. METHODS AND RESULTS: Hypertension models were induced in male CD1d knockout (CD1dko), wild‐type, and adoptive bone marrow transfer mice by angiotensin II (Ang II) or deoxycorticosterone acetate salt. Blood pressure was measured by the tail‐cuff system and radiotelemetry. Vascular injury was assessed by histologic studies or aortic ring assay. Inflammation was detected by flow cytometry, quantitative real‐time polymerase chain reaction, or ELISA. Results showed that Ang II infusion significantly reduced CD1d expression and NKT cell numbers in the aorta of mice. CD1dko mice exhibited worsened blood pressure elevation, vascular injury, and inflammatory response induced by Ang II or deoxycorticosterone acetate salt. However, these effects were markedly reversed in wild‐type mice treated with NKT cell–specific activator. Adoptive transfer of CD1dko bone marrow cells to wild‐type mice also significantly worsened Ang II–induced responses. Mechanistically, CD1dko increased Ang II–induced interleukin‐6 production and activated signal transducer and activator of transcription 3 and orphan nuclear receptor γ, subsequently inducing interleukin‐17A production. Neutralizing interleukin‐17A partially reversed Ang II–induced hypertension and vascular injury in CD1dko mice. In addition, levels of NKT cells were lower in the blood of patients with hypertension (n=57) compared with normotensive individuals (n=87). CONCLUSIONS: These findings reveal a previously unknown role for CD1d‐dependent NKT cells in hypertension and vascular injury, indicating that NKT cell activation could be a promising therapeutic target for hypertension.