Influenza Neuraminidase Virus Like Particles (NA-VLP) displaying small peptide antigen: a new carrier for an Angiotensin II (AngII) peptide hypertension vaccine

Abstract

Abstract Background Virus-like particles (VLPs) are composed of multiple protein subunits with structures that resemble natural virus particles and have been known for their efficiency in inducing immune responses. VLPs functions could also be extended to display or deliver small molecules such as drugs or antigens. A new and simple VLP, NA-VLP, was developed for displaying Angiotensin II (AngII) octapeptide hormones that raise blood pressure, as a potential antigen for the hypertension vaccine. Methods and Results NA-VLPs, which were solely made of an influenza A (H5N1) structural protein, neuraminidase (NA), had been constructed and further modified to have AngII peptides incorporated into the NA structure, immediately above the stalk, at the bottom of its head. Stably transformed insect cells were genetically engineered to produce these NA-AngII VLPs. High numbers of repetitive AngII peptides were displayed on the NA-VLP’s surface, and they were able to raise anti-AngII antibodies after one injection into hypertensive rats and decreases in the systolic blood pressure of the rats were observed. Conclusions The NA-VLPs could effectively display AngII peptides and stimulate the hypertensive rat immune system to produce antibodies, which could neutralize the AngII peptides and lower its systolic blood pressure. The NA-AngII VLPs could be developed into a new hypertension vaccine. The NA-VLPs are therefore promising carriers for peptide antigens.