Effectiveness and Safety of a Therapeutic Vaccine Against Angiotensin II Receptor Type 1 in Hypertensive Animals

Primary hypertension is a chronic disease with high morbidity, and the rate of controlled blood pressure is far from satisfactory, worldwide. Vaccination provides a promising approach for treatment of hypertension and improvement in compliance. Here, the ATRQβ-001 vaccine, a peptide (ATR-001) derived from human angiotensin II (Ang II) receptor type 1 conjugated with Qβ bacteriophage virus-like particles, was developed and evaluated in animal models of hypertension. The ATRQβ-001 vaccine significantly decreased the blood pressure of Ang II–induced hypertensive mice up to 35 mm Hg (143±4 versus 178±6 mm Hg; P=0.005) and that of spontaneously hypertensive rats up to 19 mm Hg (173±2 versus 192±3 mm Hg; P=0.003) and prevented remodeling of vulnerable hypertensive target organs. No obvious feedback activation of circulating or local renin-angiotensin system was observed. Additionally, no significant immune-mediated damage was detected in vaccinated hypertensive and nonhypertensive animals. The half-life of the anti-ATR-001 antibody was 14.4 days, surpassing that of existing chemical drugs. In vitro, the anti–ATR-001 antibody specifically bound to Ang II receptor type 1 and inhibited Ca-dependent signal transduction events, including protein kinase C-α translocation, extracellular signal-regulated kinase 1/2 phosphorylation (72% decrease; P=0.013), and elevation of intracellular Ca (68% decrease; P=0.017) induced by Ang II, but without inhibiting Ang II binding to the receptor. In conclusion, the ATRQβ-001 vaccine decreased the blood pressure of Ang II–induced hypertensive mice and spontaneously hypertensive rats effectively through diminishing the pressure response and inhibiting signal transduction initiated by Ang II. Thus, the ATRQβ-001 vaccine may provide a novel and promising method for the treatment of primary hypertension.