Therapeutic Intranasal Vaccine HB-ATV-8 Prevents Atherogenesis and Non-alcoholic Fatty Liver Disease in a Pig Model of Atherosclerosis

Abstract

Background and aims: Atherosclerosis as an inflammatory disease involved in the etiology of cardiovascular disease worldwide, in our days demands an array of different therapeutic approaches in order to soon be able to visualize an effective prevention. Based on an immunotherapeutic approach, we designed a non-invasive vaccine (HB-ATV-8), contained in a micellar nanoparticle composed of lipids and a peptide segment derived from the C-terminus of the cholesterol-ester transfer protein (CETP). Now we extend our successful proof of concept from the rabbit to a porcine model and investigated its effect in an attempt to undoubtedly establish the efficacy of vaccination in a model closer to the human.

Methods: A preclinical trial was designed to study the efficacy of vaccine HB-ATV-8 in pigs (Large White × Landrace). Male experimental animals were fed with standard diet (control), high fat diet (HFD) or the same HFD but treated with HB-ATV-8 (HFD + Vaccine) applied nasally for up to 7 months. All biochemical and enzymatic analyses were performed in peripheral venous blood and thoracic aorta and liver samples examined using conventional, two-photon excitation and second harmonic generation microscopy to identify atherosclerotic and hepatic lesions. mRNA concentrations for KLF2, ACTA2, SOD1, COL1A1 genes and protein levels for PPARα and ABCA1 were quantified in aorta and liver respectively using qPCR and Western blot analysis.

Results: The administration of vaccine HB-ATV-8 induced anti-CETP IgG antibodies and reduced atherosclerotic and hepatic lesions promoted by the high fat diet. In addition, plasma triglyceride levels of vaccine treated pigs fed the HFD were similar to those of control group, in contrast to high concentrations reached with animals exclusively fed with HFD. Moreover, HFD promotes a tendency to decrease hepatic PPARα levels and increase in aorta gene expression of KLF2, ACTA2, SOD1 and COL1A1, while vaccine application promotes recovery close to control values.

Conclusions: Vaccine HB-ATV-8 administration constitutes a promissory preventive approach useful in the control of atherogenesis and fatty liver disease. The positive results obtained, the non-invasive characteristics of the vaccine, the simple design employed in its conception and its low production cost, support the novelty of this therapeutic strategy designed to prevent the process of atherogenesis and control the development of fatty liver disease.

Keywords: Atherogenesis; CETP; NAFLD; Nasal therapeutic vaccine; Porcine model.